JP2005044964A - Surface emitting laser element, method of manufacturing the same array, and module for surface emitting laser, electronic photography system, optical interconnection system, and optical communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface emitting laser element capable of obtaining high output operation, having low element resistor and capable of high-speed operation in a single fundamental lateral mode. <P>SOLUTION: A hole constriction structure defining a hole implantation region to an active layer 106 is constituted by high resistor regions 116 provided by ion implantation, and a conductive region 117 surrounded by the regions 116 on the middle of a hole path. Also, a high-order lateral suppressing structure is constituted by selectively oxidized regions 115 formed by selectively oxidizing a semiconductor layer including Al as a constituent, and a non-oxidized region 114 surrounded by the regions 115 is provided independently from the hole constriction structure. The region 114 of the high-order lateral mode suppressing structure has an area smaller than that of the conductive region 117 of the hole constriction structure. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surface emitting laser element, a surface emitting laser array, a surface emitting laser module, an electrophotographic system, an optical interconnection system, an optical communication system, and a method for manufacturing the surface emitting laser element.
[0002]
[Prior art]
Surface emitting lasers (surface emitting semiconductor lasers) are attracting attention as communication light sources for LANs and the like because they have a smaller active layer volume and can be modulated at a higher speed than edge emitting lasers. Further, since the surface emitting laser can take out the laser output in the direction perpendicular to the substrate, it is easy to integrate the two-dimensional array, and has attracted attention as a light source for parallel optical interconnection. In addition, since the surface emitting laser element can reduce the volume of the active layer as compared with the edge emitting laser, the oscillation threshold current can be easily reduced, and extensive research has been conducted on lowering the threshold current.
[0003]
As a typical structure of a surface emitting laser element, a structure using selective oxidation as described below and a structure using hydrogen ion implantation are known.
[0004]
First, as a structure using selective oxidation, for example, Non-Patent Literature 1 and Non-Patent Literature 2 show a 0.98 μm band surface emitting laser element using InGaAs as an active layer. In the surface emitting laser elements in these non-patent documents, p-Al provided on the active layer is provided._0.9Ga_0.1In an upper distributed Bragg reflector made of As / GaAs, Al_0.98Ga_0.02An As selective oxidation layer is provided. In this surface emitting laser element, after the crystal growth, the upper distributed Bragg reflector is etched into a rectangular mesa so that the side surface of the selectively oxidized layer is exposed by etching, and water heated to 85 ° C. is heated with nitrogen gas. In a bubbling atmosphere, heat to 425 ° C and Al from the etching side toward the center of the mesa_0.98Ga_0.02The As selective oxidation layer is selectively oxidized. Al is around the mesa by selective oxidation.₂O₃An insulating region is formed by a non-oxidized region in the center of the mesa.
[0005]
In the surface emitting laser elements of Non-Patent Document 1 and Non-Patent Document 2, holes injected from the surface of the upper distributed Bragg reflector are confined to the non-oxidation conduction region at the center of the mesa and injected into the active layer. . Al₂O₃Is a very good insulator, and the hole injection region can be limited to the center of the mesa. By using such a selective oxidation structure, the oscillation threshold current can be greatly reduced. For example, in Non-Patent Document 2, a low threshold current of 900 μm is obtained in an element in which the area of the non-oxidized region is 4.5 μm × 8 μm.
[0006]
Furthermore, Al₂O₃Since the refractive index of this is about 1.6, which is lower than other semiconductor layers, a lateral refractive index difference occurs in the resonator structure, and the oscillation light is confined in the center of the mesa. It is possible to reduce and improve the efficiency of the element. However, on the contrary, since the optical confinement becomes large, it is necessary to reduce the diameter of the oxidized constriction in order to suppress the oscillation of the high-order transverse mode. Although it depends on the wavelength band, in a conventional surface emitting laser element provided with a single oxidized constriction structure, it is possible to obtain single fundamental mode oscillation by narrowing the oxidized constriction diameter to about 3 to 4 times the oscillation wavelength. Is possible. As described above, by using the selective oxidation structure, reduction of the oscillation threshold, reduction of diffraction loss, and single fundamental mode control are realized.
[0007]
Next, as a structure using hydrogen ion implantation, for example, Non-Patent Document 3 shows a 0.85 μm band surface emitting laser element using GaAs as an active layer. In the surface emitting laser element in Non-Patent Document 3, a p-type distributed Bragg reflector is provided on the active layer, and after crystal growth, hydrogen ions are implanted from the upper surface of the wafer. A part of the p-type distributed Bragg reflector in the vicinity of the active layer is increased in resistance while leaving a region to be a hole conduction region. As a result, the hole injection region is limited to a partial region of the active layer, and the oscillation threshold current is reduced. In the surface emitting laser element of Non-Patent Document 3, an oscillation threshold current of 2.5 mA is obtained by a hole injection region having a diameter of 10 μm.
[0008]
Further, Non-Patent Document 4 shows an example of a 0.85 μm band surface emitting laser element aiming at high output as a structure using both hydrogen ion implantation and selective oxidation. In the surface emitting laser element disclosed in Non-Patent Document 4, a large selective oxidation structure of a non-oxidation region is provided above and below the active layer, and a selective oxidation structure is provided in a region other than between the active layer and the selective oxidation structure. A narrowing structure of carriers by hydrogen ion implantation having a smaller narrowing diameter is provided.
[0009]
The selective oxidation structure in this element is provided for confining the transverse mode, but the oxidation diameter is large and the effect of suppressing the high-order transverse mode itself is small. However, the area of the high resistance region by hydrogen injection provided in the p conductivity type distributed Bragg reflector is made smaller than the area of the non-oxidized region, and the region where the carriers are injected is a small region at the center of the mesa. By limiting to the above, the gain for the high-order transverse mode is suppressed, and single fundamental transverse mode oscillation up to a high output of 5 mW is achieved.
[0010]
[Non-Patent Document 1]
Applied Physics Letters vol. 66, no. 25, pp. 3413-3415, 1995
[0011]
[Non-Patent Document 2]
Electronics Letters No. 24, Vol. 30, pp. 2043-2044, 1994
[0012]
[Non-Patent Document 3]
Electronics Letters No. 5, Vol. 27, pp. 457-458, 1991
[0013]
[Non-Patent Document 4]
IEEE Photonics Technology Letters Vol. 13, no. 9, pp. 927-929, 2001
[0014]
[Problems to be solved by the invention]
In many applications of surface-emitting laser elements such as long-distance communication light sources using optical fibers, writing light sources for electrophotographic systems, optical disks, etc., the demand for unimodal beam shape and single fundamental transverse mode oscillation is Very expensive.
[0015]
However, conventionally, in order to obtain single transverse mode oscillation by the current confinement structure by selective oxidation of Non-Patent Document 1 and Non-Patent Document 2, it is necessary to reduce the oxidation confinement diameter and suppress higher-order mode oscillation. . Although the threshold current can be reduced by reducing the oxidized constriction diameter, the region contributing to oscillation is reduced, so that it becomes difficult to obtain a high output.
[0016]
Furthermore, there is a problem that the element resistance increases due to the reduction of the area of the conduction region, and the output saturation due to the heat generation of the element makes it difficult to oscillate to a high output. In particular, in the p-type semiconductor material, since the effective mass of holes is large and the mobility is small, the resistance is originally high, and the increase in resistance when the oxidized confinement diameter is reduced becomes very remarkable. As a method of reducing the resistance of the p-conductivity type distributed Bragg reflector, there is a method of inserting a hetero spike buffer layer or the like at the interface, but even in this case, the resistance due to oxidation constriction is still large.
[0017]
Conversely, when the oxidized confinement diameter is increased, a relatively high output can be obtained by widening the oscillation region, but the higher-order transverse mode suppression effect by the oxidized constriction layer is weakened. Oscillation in the transverse mode will occur.
[0018]
As described above, there is a contradictory relationship between oscillating a single fundamental transverse mode and obtaining a high output. Conventionally, depending on the wavelength band, a single fundamental transverse mode oscillation is achieved by a single oxide constriction structure. In order to obtain, one side or diameter of about 3 to 4 times the oscillation wavelength is required. However, in the conventional oxidized surface emitting laser element, current confinement and single fundamental transverse mode control are performed simultaneously by a selective oxidation structure having a small non-oxidized region, and an extremely low threshold current and a single fundamental transverse mode oscillation are obtained. Therefore, the element has a very high resistance, and the upper limit of the output is about 2 mW due to the influence of heat generation due to the high resistance and the reduction of the oscillation region. Also, high speed operation is difficult due to the high resistance of the element.
[0019]
In addition, the conventional hydrogen ion implantation surface emitting laser element shown in Non-Patent Document 3 does not have a built-in waveguide structure inside the element, and the transverse mode confinement is caused by a refractive index change caused by energization. Is going by. That is, the current path in the center of the mesa generates heat when energized, the refractive index of this region increases, and a waveguide structure is formed. Such a phenomenon is called a thermal lens effect. The refractive index change caused by the thermal lens effect is 5 × 10.^-4K^-1The degree and slightness. Therefore, in order to suppress higher-order transverse modes, it is not necessary to reduce the hole confinement diameter as in the case of an oxidized surface emitting laser element. Since the structure does not have a structure, it is sensitive to changes in the refractive index due to the thermal lens effect, and the stability of the transverse mode is poor. That is, the transverse mode is unstable with respect to changes in the injection current of the element, and it is difficult to obtain single fundamental transverse mode oscillation.
[0020]
Furthermore, in the hydrogen ion implanted surface emitting laser element, it takes time until the temperature of the semiconductor layer sufficiently changes before the anti-waveguide structure in which the thermal lens effect is generated by the plasma effect is canceled and the waveguide structure is formed. In general, it is known to cause an oscillation delay of the order of nanoseconds. Therefore, there is a problem that the high-speed operation of the element is hindered.
[0021]
In the surface emitting laser element shown in Non-Patent Document 4, the gain region is limited to a very small region at the center of the mesa in order to suppress higher-order transverse mode oscillation, and the p-conductivity type distributed Bragg reflection is performed. The constriction diameter of the hole confinement structure by hydrogen ion implantation provided in the chamber is narrowed down. Therefore, as described above, the resistance of the constriction portion is high, and it is considered that the output is affected by the heat generated by the element. Similarly, it is expected that high speed operation is difficult due to the increase in resistance.
[0022]
As described above, both the conventional oxidation type surface emitting laser element and the hydrogen injection type surface emitting laser element have a problem that it is difficult to obtain a high output in single fundamental transverse mode oscillation. In addition, the oxidation type surface emitting laser element has a problem that high-speed operation is difficult because of the high resistance due to oxidation constriction and the hydrogen injection type surface emitting laser element because of the oscillation delay due to the thermal lens effect.
[0023]
The present invention relates to a surface emitting laser element, a surface emitting laser array, a surface emitting laser module, an electrophotographic system, and an optical device capable of obtaining a high output operation in a single fundamental transverse mode oscillation and further having a low element resistance and capable of high speed operation. An object of the present invention is to provide an interconnection system, an optical communication system, and a method of manufacturing a surface emitting laser element.
[0024]
[Means for Solving the Problems]
To achieve the above object, according to the first aspect of the present invention, an active layer, a pair of distributed Bragg reflectors facing each other across the active layer, a hole path reaching the active layer from the first electrode, In a surface emitting laser element comprising an electron path that reaches the active layer from the second electrode,
In the middle of the hole passage, a hole confinement that defines a hole injection region into the active layer, which is configured by a high resistance region provided by ion implantation and a conduction region surrounded by the high resistance region In addition to the hole confinement structure, a structure is provided that includes a selectively oxidized region formed by selectively oxidizing a semiconductor layer containing Al as a constituent element and a non-oxidized region surrounded by the selectively oxidized region. A high-order transverse mode suppression structure is provided, and the non-oxidized region of the high-order transverse mode suppression structure has a smaller area than the conduction region of the hole confinement structure.
[0025]
According to a second aspect of the present invention, in the surface emitting laser element according to the first aspect, the high-order transverse mode suppression structure is provided in the middle of the electron path.
[0026]
According to a third aspect of the present invention, in the surface emitting laser element according to the first aspect, the high-order transverse mode suppression structure is provided avoiding the electron passage and the hole passage. .
[0027]
According to a fourth aspect of the present invention, in the surface emitting laser element according to any one of the first to third aspects, the pair of distributed Bragg reflectors is made of a semiconductor material. It is said.
[0028]
According to a fifth aspect of the present invention, in the surface-emitting laser element according to any one of the first to third aspects, the pair of distributed Bragg reflectors are made of a semiconductor material and a dielectric material. It is characterized by being.
[0029]
According to a sixth aspect of the present invention, in the surface-emitting laser device according to any one of the first to fifth aspects, at least one of the pair of distributed Bragg reflectors is an n-conductivity-type semiconductor Bragg reflector. And a tunnel junction between the n-conductivity type semiconductor Bragg reflector and the active layer.
[0030]
The invention according to claim 7 is the surface emitting laser element according to any one of claims 1 to 5, wherein at least one of the pair of distributed Bragg reflectors is a distributed Bragg reflector, A non-doped semiconductor Bragg reflector, or a Bragg reflector including a region made up of a part of a non-doped semiconductor Bragg reflector, and a region formed of the non-doped semiconductor Bragg reflector or a non-doped semiconductor Bragg reflector and an active layer An electrode for injecting carriers is provided in the semiconductor layer between the two layers.
[0031]
The invention according to claim 8 is the surface emitting laser element according to any one of claims 1 to 7, wherein the higher-order transverse mode suppression structure provided in the middle of the electron path, or the electron And the high-order transverse mode suppression structure provided in the area | region which avoided the channel | path of the said hole is characterized by being plural.
[0032]
The invention according to claim 9 is the surface-emitting laser element according to any one of claims 1 to 8, wherein the group III element constituting the active layer is selected from among Al, Ga, and In. It includes at least one, and includes at least one of As and P as a group V element constituting the active layer, and has an oscillation wavelength shorter than 1.1 μm.
[0033]
The invention according to claim 10 is the surface-emitting laser device according to any one of claims 1 to 8, wherein at least one of Ga and In is used as a group III element constituting the active layer. And the group V element constituting the active layer includes at least one of As, P, N, and Sb, and has an oscillation wavelength longer than 1.1 μm.
[0034]
The invention according to claim 11 is a surface-emitting laser array comprising the surface-emitting laser element according to any one of claims 1 to 10.
[0035]
According to a twelfth aspect of the present invention, in the surface emitting laser array according to the eleventh aspect, the surface emitting laser array has different oscillation wavelengths due to different areas of the non-oxidized regions of the high-order transverse mode suppression structure. It is characterized by being composed of more than one type of surface emitting laser element.
[0036]
According to a thirteenth aspect of the present invention, in the surface emitting laser array according to the twelfth aspect, each of the surface emitting laser elements constituting the surface emitting laser array has a plurality of higher-order transverse mode suppression structures of two or more layers. It is characterized by having.
[0037]
The invention according to claim 14 is characterized in that the surface-emitting laser element according to any one of claims 1 to 10 or the surface-emitting laser array according to claim 11 is used. This is a surface emitting laser module.
[0038]
In the invention according to claim 15, the surface emitting laser element according to any one of claims 1 to 10 or the surface emitting laser array according to claim 11 is used as a writing light source. An electrophotographic system characterized by the above.
[0039]
In the invention described in claim 16, the surface emitting laser element according to any one of claims 1 to 10 or the surface emitting laser array according to claim 11 is used as a light source. This is an optical interconnection system that is characterized.
[0040]
The invention described in claim 17 is characterized in that the surface emitting laser element according to any one of claims 1 to 10 or the surface emitting laser array according to claim 11 is used as a light source. An optical communication system is characterized.
[0041]
The invention according to claim 18 is characterized in that the surface emitting laser array according to claim 12 or claim 13 is used as a light source.
[0042]
According to a nineteenth aspect of the present invention, there is provided a surface-emitting laser array comprising two or more types of surface-emitting laser elements having different oscillation wavelengths due to different areas of the non-oxidized regions of the higher-order transverse mode suppressing structure. The method is characterized in that the areas of the non-oxidized regions of the high-order transverse mode control layer are made different by making the diameters of the mesas including the higher-order transverse mode control layer different.
[0043]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0044]
(First embodiment)
The first embodiment of the present invention includes an active layer, a pair of distributed Bragg reflectors facing each other across the active layer, a hole path reaching the active layer from the first electrode, and an active from the second electrode. In a surface emitting laser element comprising an electron path reaching the layer,
In the middle of the hole passage, a hole confinement that defines a hole injection region into the active layer, which is configured by a high resistance region provided by ion implantation and a conduction region surrounded by the high resistance region In addition to the hole confinement structure, a structure is provided that includes a selectively oxidized region formed by selectively oxidizing a semiconductor layer containing Al as a constituent element and a non-oxidized region surrounded by the selectively oxidized region. A high-order transverse mode suppression structure is provided, and the non-oxidized region of the high-order transverse mode suppression structure has a smaller area than the conduction region of the hole confinement structure.
[0045]
According to the configuration of the first embodiment, the high-order transverse mode suppression structure provided by selectively oxidizing the semiconductor layer containing Al in the composition forms a transverse mode optical confinement structure in the surface emitting laser, and is driven. It has a function of stabilizing the oscillation state against a change in state. Further, by providing a small area of the non-oxidized region, it is possible to suppress high-order transverse mode oscillation and obtain single fundamental transverse mode oscillation.
[0046]
In addition, the hole confinement structure having a hole confinement region relatively large with respect to the non-oxidized region in the higher-order transverse mode suppression structure formed by ion implantation prevents carrier diffusion to the side surface of the mesa, It has a function to obtain high internal quantum efficiency.
[0047]
In addition, the configuration in which the high-order transverse mode suppression structure and the hole confinement structure are provided separately enables the area of the hole confinement region to be increased, the oscillation region can be expanded, and the element resistance Can be reduced. A high output operation is possible by reducing the increase in element resistance.
[0048]
As described above, the configuration of the first embodiment can provide a surface-emitting laser element that has a low element resistance, can obtain a high output in a single fundamental transverse mode, and can operate at high speed.
[0049]
(Second Embodiment)
According to a second embodiment of the present invention, in the surface emitting laser element according to the first embodiment, the high-order transverse mode suppression structure is provided in the middle of the electron path.
[0050]
According to the configuration of the second embodiment, the high-order transverse mode suppression structure provided by selectively oxidizing a semiconductor layer containing Al in the composition provided in the middle of the electron path has a transverse mode in the surface emitting laser. An optical confinement structure is formed, and the oscillation state is stabilized against changes in the driving state. Further, by providing a small area of the non-oxidized region, it is possible to suppress high-order transverse mode oscillation and obtain single fundamental transverse mode oscillation.
[0051]
Furthermore, since the n-conductivity type semiconductor has an electrical resistance that is about an order of magnitude lower than that of the p-conductivity type semiconductor, the high-order transverse mode suppression structure in the second embodiment has a high resistance without significantly increasing the element resistance. Next transverse mode oscillation can be suppressed.
[0052]
As described above, in the first and second embodiments, the hole confinement structure and the high-order transverse mode suppression structure are provided separately from each other, and the minute amount necessary for suppressing the oscillation of the high-order transverse mode is provided. A high-order transverse mode suppression structure having a non-oxidized region is provided in the middle of an electron path that is difficult to increase the resistance, thereby preventing the resistance of the element from increasing. In addition, the area of the conduction region in the hole confinement structure is increased, the oscillation region is expanded, and the resistance of the element is prevented from being increased.
[0053]
(Third embodiment)
According to a third embodiment of the present invention, in the surface emitting laser element according to the first embodiment, the high-order transverse mode suppression structure is provided to avoid the electron passage and the hole passage. Yes.
[0054]
According to the configuration of the third embodiment, the high-order transverse mode suppression structure provided by selectively oxidizing the semiconductor layer containing Al in the composition provided avoiding the electron passage and the hole passage is provided in the surface emitting laser. A transverse mode light confinement structure is formed, and the oscillation state is stabilized against a change in driving state. Furthermore, by providing a small area of the non-oxidized region, the high-order transverse mode oscillation is suppressed and a single fundamental transverse mode oscillation is obtained.
[0055]
Furthermore, the high-order transverse mode suppression structure in the third embodiment has no influence on the element resistance because it is provided avoiding the electron path and the hole path, and therefore the element resistance is not increased. Higher-order transverse mode oscillation can be suppressed.
[0056]
As described above, in the first and third embodiments, the hole confinement structure and the high-order transverse mode suppression structure are provided separately from each other, and the minute amount necessary for suppressing the oscillation of the high-order transverse mode is provided. A high-order transverse mode suppressing structure having a non-oxidized region is provided in a region avoiding the hole passage and the electron passage to prevent the device from increasing in resistance. In addition, the area of the conduction region in the hole confinement structure is increased, the oscillation region is expanded, and the resistance of the element is prevented from being increased.
[0057]
(Fourth embodiment)
The fourth embodiment of the present invention is characterized in that, in the surface emitting laser element of any one of the first to third embodiments, the pair of distributed Bragg reflectors is made of a semiconductor material.
[0058]
According to the configuration of the fourth embodiment, the surface emitting laser element of any one of the first to third embodiments can be obtained with high accuracy by a single crystal growth. In addition, an element can be obtained with good controllability and yield by a semiconductor process with good controllability.
[0059]
(Fifth embodiment)
According to a fifth embodiment of the present invention, in the surface emitting laser element according to any one of the first to third embodiments, the pair of distributed Bragg reflectors is made of a semiconductor material and a dielectric material. It is a feature.
[0060]
The dielectric material has less light absorption loss than the semiconductor material, and it is possible to use a material having a large refractive index difference compared to the semiconductor material, and a high reflectance can be obtained with a small number of layers. . Therefore, according to the fifth embodiment, the surface-emitting laser element of the present invention having excellent efficiency can be obtained by the dielectric distributed Bragg reflector with little absorption loss.
[0061]
That is, according to the fifth embodiment, a highly efficient surface emitting laser with low element resistance, high output in a single fundamental transverse mode, high-speed operation, and reduced loss due to light absorption. An element can be provided.
[0062]
(Sixth embodiment)
According to a sixth embodiment of the present invention, in the surface emitting laser element according to any one of the first to fifth embodiments, at least one of the pair of distributed Bragg reflectors includes an n-conductivity type semiconductor Bragg reflector. In addition, a tunnel junction is provided between the n-conductivity type semiconductor Bragg reflector and the active layer.
[0063]
By reverse-biasing the pn junction subjected to high-concentration doping, holes are generated by band-to-band tunneling, and holes can be injected into the active region. Therefore, hole injection is possible using a tunnel junction and an n-conductivity distributed Bragg reflector. Further, the n-conduction type distributed Bragg reflector has a lower absorption loss than the p-conduction type distributed Bragg reflector.
[0064]
Therefore, according to the configuration of the sixth embodiment, instead of the p-conduction type semiconductor distributed Bragg reflector, an n-type semiconductor distributed Bragg reflector with low absorption loss has characteristics such as low threshold current and high slope efficiency. A surface emitting laser element is obtained.
[0065]
That is, according to the sixth embodiment, a highly efficient surface emitting laser with low element resistance, high output in a single fundamental transverse mode, high speed operation, and reduced loss due to light absorption. An element can be provided.
[0066]
(Seventh embodiment)
According to a seventh embodiment of the present invention, in the surface emitting laser element according to any one of the first to fifth embodiments, at least one of the pair of distributed Bragg reflectors is a non-doped semiconductor Bragg. A reflector, or a Bragg reflector partially including a region composed of a non-doped semiconductor Bragg reflector, and further between the non-doped semiconductor Bragg reflector or a region composed of a non-doped semiconductor Bragg reflector and the active layer An electrode for injecting carriers is provided in the semiconductor layer.
[0067]
Semiconductor materials generally tend to increase light absorption by free carriers with increasing doping concentration. In addition, particularly in a p-conductivity type semiconductor, light absorption due to absorption between valence bands occurs in addition to this. On the other hand, according to the configuration of the seventh embodiment, a surface emitting laser element excellent in characteristics such as a low threshold current and a high slope efficiency can be obtained by using a non-doped semiconductor distributed Bragg reflector with a small absorption loss. .
[0068]
That is, according to the seventh embodiment, a highly efficient surface emitting laser with low element resistance, high output in a single fundamental transverse mode, high speed operation, and reduced loss due to light absorption. An element can be provided.
[0069]
(Eighth embodiment)
According to an eighth embodiment of the present invention, in the surface emitting laser element of any one of the first to seventh embodiments, a high-order transverse mode suppression structure provided in the middle of an electron path, or a path for electrons and holes The structure is such that there are a plurality of higher-order transverse mode suppression structures provided in the region avoiding the above.
[0070]
According to the configuration of the eighth embodiment, a non-area having a relatively small area with respect to the hole confinement region provided in the middle of the electron passage or in a region avoiding the passage of electrons and holes. By using a plurality of higher-order transverse mode suppression structures having an oxidation region, it is possible to more effectively suppress higher-order transverse mode oscillation.
[0071]
(Ninth embodiment)
According to a ninth embodiment of the present invention, in the surface emitting laser element according to any one of the first to eighth embodiments, at least one of Al, Ga, and In is used as a group III element constituting the active layer. In addition, the group V element constituting the active layer includes at least one of As and P, and the oscillation wavelength is shorter than 1.1 μm.
[0072]
In a surface emitting laser element having an oscillation wavelength shorter than 1.1 μm, in order to perform single fundamental transverse mode control, the length or diameter of one side of the non-oxidized region needs to be about 5 μm or less. The increase is particularly noticeable. However, according to the configuration of the ninth embodiment, the element resistance can be reduced very effectively.
[0073]
This can provide a great effect particularly in a surface emitting laser in the visible band. For example, when an AlGaInP-based material is used as an active layer of a surface emitting laser element, a red surface emitting laser element having an oscillation wavelength in the 660 nm band can be obtained. In order to obtain the transverse mode oscillation, the length or diameter of one side of a very fine non-oxidized region of 3 μm or less is required, and the increase in resistance due to constriction becomes very significant. However, in the element of the present invention, the high-order transverse mode suppressing structure that requires a small non-oxidized region area is in the middle of an electron path (in an n-type semiconductor) where resistance is not easily increased, or electrons that do not contribute to resistance. Since it is provided in a region avoiding the passage and the hole passage, single basic transverse mode control can be performed without increasing the resistance of the element.
[0074]
As described above, according to the configuration of the ninth embodiment, in the surface emitting laser element whose oscillation wavelength is shorter than 1.1 μm, the element resistance is reduced and the high output operation in the single fundamental transverse mode oscillation is achieved. Is possible.
[0075]
(Tenth embodiment)
The tenth embodiment of the present invention includes at least one of Ga and In as a group III element constituting the active layer in the surface emitting laser element of any one of the first to eighth embodiments, Further, the group V element constituting the active layer includes at least one of As, P, N, and Sb, and the oscillation wavelength is longer than 1.1 μm.
[0076]
A surface emitting laser element using GaInNAs (Sb) or the like as an active layer can obtain oscillation in 1.3 μm band and 1.55 μm band which are important wavelength bands in optical fiber communication. Moreover, since a high characteristic temperature is obtained, it is highly important as a subscriber light source. Particularly in the 1.3 μm band, high-speed communication using a quartz single mode fiber is possible, but in order to obtain a high coupling rate with an optical fiber, it is strongly desired to be a single fundamental transverse mode oscillation. In the surface emitting laser element of the present invention, single fundamental transverse mode oscillation can be obtained up to a high output, so that the coupling rate with the fiber does not vary due to variations in driving conditions. Further, since the element resistance is low as described above, high speed operation is possible.
[0077]
Therefore, according to the configuration of the tenth embodiment, an element having an oscillation wavelength in a long wavelength region having particularly excellent characteristics can be obtained.
[0078]
(Eleventh embodiment)
The eleventh embodiment of the present invention is a surface emitting laser array in which a plurality of surface emitting laser elements of any of the first to tenth embodiments are arranged.
[0079]
According to the eleventh embodiment, since the surface emitting laser array is configured by the surface emitting laser element according to any one of the first to tenth embodiments, the element resistance is low and the single basic transverse mode is high. It is possible to provide a surface emitting laser array capable of obtaining an output and capable of high speed operation.
[0080]
(Twelfth embodiment)
According to a twelfth embodiment of the present invention, in the surface emitting laser array according to the eleventh embodiment, the surface emitting laser array has different oscillation wavelengths due to different areas of non-oxidized regions of the high-order transverse mode suppression structure. It is characterized by comprising two or more surface emitting laser elements.
[0081]
An oxidation surface emitting laser element has a feature that the resonance wavelength of the resonator changes depending on the area of the non-oxidized region in the selective oxidation structure. By reducing the area of the non-oxidized region, the oscillation wavelength (resonance wavelength) Is known to shift by a short wavelength. The reason why the wavelength changes due to the size of the area of the non-oxidized region is that the oxide region has a confinement action for the oscillation transverse mode, so the lateral mode spread changes as the area of the non-oxidized region changes. This is because the vertical resonance condition of the resonator changes.
[0082]
For example, the document “IEEE Journal of Selected Topics In Quantum Electronics Vol. 3, No. 2, pp. 344, 1997” and the document “IEEE Journal of Quant. From the numerical calculation, the short wavelength shift amount of the oscillation wavelength (resonance wavelength) with respect to the area of the non-oxidized region in the 0.98 μm band element is estimated. The results of these documents show that the short wavelength shift starts gradually from the diameter of the non-oxidized region of about 5 μm, and the short wavelength shift increases rapidly from the diameter of the non-oxidized region of about 2 μm or less.
[0083]
Actually, in the document “IEEE Photonics Technology Letter Vol. 8, No. 7, pp. 858 1996”, devices having different areas of non-oxidized regions were fabricated, and 2 × 2 with a wavelength interval of about 1 nm in the 0.98 μm band. An example of producing a surface emitting laser array has been reported. In this case, the minimum stenosis diameter is 2.0 μm, and the maximum stenosis diameter is 3.5 μm.
[0084]
However, in a conventional surface emitting laser element that performs current confinement and high-order transverse mode suppression with a single selective oxidation structure, the distribution in the array of threshold current, optical output, etc., is very high by changing the oxidation confinement diameter. The problem of becoming larger occurs. Further, as described above, there is a problem that by making the oxidized constriction diameter minute, the resistance of the constriction region increases drastically and it is difficult to obtain a high output due to heat generation. Actually, in the above document, it is described that even in an element having a maximum oxidized confinement diameter of 3.5 μm, the maximum light output was about 0.38 mW due to element heat generation. In an element having a smaller oxidized confinement diameter than this, the light output is considered to be further smaller due to the influence of heat generation due to the increase in resistance. As described above, it is difficult to produce a surface emitting laser array capable of high output operation when a multi-wavelength surface emitting laser array is produced by the above-described method.
[0085]
Further, in order to obtain a wider-band multiwavelength surface emitting laser array, it is necessary to further reduce the area of the non-oxidized region. Actually, when the diameter of the non-oxidized region is about 1 μm or less, the light loss due to the selective oxidation structure starts to increase rapidly. Therefore, this level is considered to be the lower limit for actual operation. When the area of the non-oxidized region is reduced to about this value, the element heat generation (high resistance) increases drastically and it is very difficult to obtain oscillation.
[0086]
According to the present invention, the hole confinement structure by ion implantation and the high-order transverse mode suppression structure by selective oxidation are individually provided, and the high-order transverse mode suppression structure is further made of an n conductivity type that is difficult to increase in resistance. The semiconductor layer is provided in a region other than the carrier (electron, hole) passage not related to the electrical resistance. For this reason, the increase in resistance when the area of the non-oxidized region of the high-order transverse mode suppression structure is made small is small as compared with the element of the conventional structure, or not in the latter case. Therefore, since heat generation due to high resistance can be suppressed to a low level, fundamental lateral mode oscillation and high output can be obtained with respect to an element having a small area of the non-oxidized region of the high-order transverse mode suppression structure as described above. It is possible to reduce the variation in light output between elements. Furthermore, by making the area of the confinement region of the hole confinement structure separately provided by ion implantation for the elements in the array, variation in characteristics such as oscillation threshold current and operating voltage can be extremely reduced. Is possible.
[0087]
As described above, according to the twelfth embodiment, it is possible to obtain a multi-wavelength surface emitting laser array capable of performing single fundamental transverse mode oscillation up to high output with little variation in characteristics such as oscillation threshold current and output. That is, according to the twelfth embodiment, it is possible to provide a multi-wavelength surface emitting laser array that has a low element resistance, a high output in a single fundamental transverse mode, and a high-speed operation.
[0088]
(13th Embodiment)
According to a thirteenth embodiment of the present invention, in the surface emitting laser array according to the twelfth embodiment, each of the surface emitting laser elements constituting the surface emitting laser array includes a plurality of higher-order transverse mode suppression structures having two or more layers. It is characterized by having.
[0089]
According to the configuration of the thirteenth embodiment, the high-order transverse mode suppression structure is a multilayer of two or more layers, so that the effect of confining the transverse mode of light is increased, and the oscillation wavelength (resonance wavelength) is more effectively achieved. Can be shifted by a short wavelength, and a wider-band multiwavelength surface emitting laser array can be obtained. That is, according to the thirteenth embodiment, a multi-wavelength surface emitting laser array having a low element resistance, a higher output in a single fundamental transverse mode, a high-speed operation, and a wider wavelength band is provided. be able to.
[0090]
(Fourteenth embodiment)
The fourteenth embodiment of the present invention is a surface emitting laser module in which the surface emitting laser element of any one of the first to tenth embodiments or the surface emitting laser array of the eleventh embodiment is used. .
[0091]
The surface-emitting laser elements of the first to tenth embodiments and the surface-emitting laser array of the eleventh embodiment can stably oscillate to a high output in a single fundamental transverse mode. In addition, the device resistance is low and high speed operation is possible. Therefore, the surface emitting laser element according to any one of the first to tenth embodiments or the surface emitting laser module using the surface emitting laser array according to the eleventh embodiment can operate at high speed, and the fiber The coupling rate is stable without fluctuation, and the reliability is high.
[0092]
That is, according to the fourteenth embodiment, it is possible to provide a highly reliable surface emitting laser module that can obtain high output in the single basic transverse mode and can operate at high speed.
[0093]
(Fifteenth embodiment)
The fifteenth embodiment of the present invention is an electrophotographic system in which the surface emitting laser element of any one of the first to tenth embodiments or the surface emitting laser array of the eleventh embodiment is used as a writing light source. It is.
[0094]
The surface emitting laser elements of the first to tenth embodiments and the surface emitting laser array of the eleventh embodiment can oscillate to a high output in a single fundamental transverse mode. In addition, since the outgoing beam is circular and has high positional accuracy between arrays, it is possible to easily collect multiple beams with the same lens with good reproducibility, which makes the optical system simple, A low-cost electrophotographic system can be configured. Further, since a high output can be obtained in the basic transverse mode, when an array is used, particularly high-speed writing is possible, and a high-speed electrophotographic system can be realized.
[0095]
That is, according to the fifteenth embodiment, high-speed operation writing is possible, and a high-definition electrophotographic system can be provided.
[0096]
(Sixteenth embodiment)
The sixteenth embodiment of the present invention is an optical interconnection system in which the surface emitting laser element of any one of the first to tenth embodiments or the surface emitting laser array of the eleventh embodiment is used as a light source. It is.
[0097]
The surface-emitting laser elements according to the first to fifteenth embodiments and the surface-emitting laser array according to the eleventh embodiment have a single fundamental transverse mode, can oscillate to a high output, have high coupling with optical fibers, The transverse mode is stable even when the operating state changes. Furthermore, since the element resistance is low, high-speed operation is possible. Therefore, by using these as the light source, a highly reliable optical interconnection system can be realized.
[0098]
That is, according to the sixteenth embodiment, it is possible to provide a highly reliable optical interconnection system in which the coupling with the fiber is stable and high-speed transmission is possible.
[0099]
(Seventeenth embodiment)
The seventeenth embodiment of the present invention is an optical communication system in which the surface emitting laser element of any one of the first to tenth embodiments or the surface emitting laser array of the eleventh embodiment is used as a light source. is there.
[0100]
The surface-emitting laser elements according to the first to fifteenth embodiments and the surface-emitting laser array according to the eleventh embodiment have a single fundamental transverse mode, can oscillate to a high output, have high coupling with optical fibers, The transverse mode is stable even when the operating state changes. Furthermore, since the element resistance is low, high-speed operation is possible. Therefore, by using these as light sources, a highly reliable optical communication system can be realized.
[0101]
In addition, since the basic transverse mode output is high, an optical communication system capable of long-distance communication can also be realized.
[0102]
As described above, according to the seventeenth embodiment, it is possible to provide a highly reliable optical communication system in which coupling with a fiber is stable and high-speed communication is possible.
[0103]
(Eighteenth embodiment)
The eighteenth embodiment of the present invention is an optical communication system in which the surface emitting laser array of the twelfth or thirteenth embodiment is used as a light source.
[0104]
In the surface emitting laser arrays of the twelfth and thirteenth embodiments, there are few variations in the characteristics of the surface emitting laser elements in the surface emitting laser array, the drive control of the surface emitting laser array is easy, and high in single basic transverse mode. Output operation is possible. Further, since the element resistance is low, high speed operation is possible. Further, since the surface emitting laser arrays of the twelfth and thirteenth embodiments are multi-wavelength arrays, wavelength division multiplexing communication is possible.
[0105]
Therefore, by using these for the light source, a highly reliable wavelength division multiplexing optical communication system can be realized.
[0106]
Thus, according to the eighteenth embodiment, it is possible to provide a highly reliable wavelength division multiplexing communication system in which coupling with a fiber is stable and high-speed transmission is possible.
[0107]
(Nineteenth embodiment)
According to a nineteenth embodiment of the present invention, a surface emitting laser array including two or more types of surface emitting laser elements having different oscillation wavelengths due to different areas of non-oxidized regions of a high-order transverse mode suppressing structure is manufactured. The method is characterized in that the areas of the non-oxidized regions of the higher order transverse mode control layer are made different by making the diameters of the mesas including the higher order transverse mode control layer different.
[0108]
According to the nineteenth embodiment, the surface emitting laser arrays of the twelfth and thirteenth embodiments can be easily obtained with good controllability, good yield, and low cost.
[0109]
【Example】
Next, examples of the present invention will be described.
[110]
(First embodiment)
FIG. 1 is a diagram showing a surface emitting laser element according to a first embodiment. The surface emitting laser element of FIG._0.15Ga_0.85This is a 0.85 μm band surface emitting laser device having an As multiple quantum well structure as an active layer. The structure will be described below according to the manufacturing process.
[0111]
The surface emitting laser element of FIG. 1 is crystal-grown by metal organic chemical vapor deposition (MOCVD), and trimethylaluminum (TMA), trimethylgallium (TMG), and trimethylindium (TMI) are used as group III materials. Used as a group V raw material, arsine (AsH₃) Gas is used. CBr is also used for p-type dopants.₄And the n-type dopant is H₂Se is used.
[0112]
Specifically, the element of FIG. 1 includes an n-GaAs buffer layer 102, an n-Al substrate on an n-GaAs substrate 101._0.9Ga_0.1As / Al_0.15Ga_0.8536 cycles of n-Al with one pair of As_0.9Ga_0.1As / Al_0.15Ga_0.85As lower semiconductor distributed Bragg reflector 103, non-doped Al_0.15Ga_0.85As resonator spacer 105, GaAs / Al_0.15Ga_0.85As multiple quantum well active layer 106, non-doped Al_0.15Ga_0.85As resonator spacer 107, p-Al with 20 periods_0.9Ga_0.1As / Al_0.15Ga_0.85The As upper semiconductor distributed Bragg reflector 108 is formed by sequentially growing crystals. Moreover, Al which becomes the outermost surface layer of the upper distributed Bragg reflector 108_0.15Ga_0.85In the As layer, a contact layer (not shown) having a high concentration of p-type dopant (carbon) in the vicinity of the surface is provided.
[0113]
N-Al_0.9Ga_0.1As / Al_0.15Ga_0.85An n-AlAs selective oxidation layer 104 is provided in the As lower distributed Bragg reflector 103, and the n-AlAs selective oxidation layer 104 is oxidized in an oxidized region 115 (black in the drawing). The region shown here; the same applies to the following embodiments) and the non-oxidized region 114 that has not been oxidized. P-Al_0.9Ga_0.1As / Al_0.15Ga_0.85In the As upper distributed Bragg reflector 108, an ion implantation high resistance region 116 and an ion non-implant conduction region 117 are provided.
[0114]
Here, n and p-Al corresponding to the low refractive index layers of the upper distributed Bragg reflector 108 and the lower distributed Bragg reflector 103 are used._0.9Ga_0.1As layers 103a and 108a and n and p-Al corresponding to the high refractive index layers_0.15Ga_0.85The thickness of the As layers 103b and 108b is set to a layer thickness at which the phase change of the oscillation light in each semiconductor layer is π / 2 so as to satisfy the multiple reflection phase condition of the distributed Bragg reflector (for each layer) (See FIG. 2). The specific thickness of each layer is Al_0.9Ga_0.1As layers 103a and 108a are 69.8 nm, Al_0.15Ga_0.85The As layers 103b and 108b are 59.7 nm.
[0115]
FIG. 2 is a diagram showing in detail the resonance region (resonator region) of the surface emitting laser element of FIG. 1 together with the standing wave of the oscillation light. Hereinafter, the resonance region is defined as a region sandwiched between Bragg reflectors. In the element of the first embodiment, a region indicated by reference numeral 113 in FIG. 1 is a resonance region. FIG. 2 shows the resonance region 113 and n-Al._0.9Ga_0.1As lower semiconductor distributed Bragg reflector low refractive layer 103a and n-Al_0.15Ga_0.85N-Al with As lower semiconductor distributed Bragg reflector high refractive layer 103b_0.9Ga_0.1As / Al_0.15Ga_0.85The structure of one period of the As lower semiconductor distributed Bragg reflector 103 and p-Al_0.9Ga_0.1As upper semiconductor distributed Bragg reflector low refractive layer 108a and p-Al_0.15Ga_0.85P-Al with As upper semiconductor distributed Bragg reflector high refractive layer 108b_0.9Ga_0.1As / Al_0.15Ga_0.85The structure of one period of the As upper semiconductor distributed Bragg reflector 108 is shown.
[0116]
Here, in the surface emitting laser element shown in FIG. 1, as shown in FIG. 2, n-Al is in contact with the resonance region._0.9Ga_0.1An n-AlAs selectively oxidized layer 104 is provided in the As lower semiconductor distributed Bragg reflector low-refractive layer 103a. The thickness of the n-AlAs selective oxidation layer is 30 nm. N-AlAs provided with an n-AlAs selective oxidation layer_0.9Ga_0.1Only the thickness of the As lower semiconductor distributed Bragg reflector low-refractive layer 103a is set such that the phase change of the oscillation light in each region including the n-AlAs layer 104 is 3π / 2.
[0117]
Non-doped Al that forms the resonance region_0.15Ga_0.85As resonator spacer layer 105, non-doped GaAs / Al_0.15Ga_0.85As multiple quantum well active layer 106, non-doped Al_0.15Ga_0.85The As resonator spacer layer 107 forms a 1λ resonator structure. Non-doped GaAs / Al_0.15Ga_0.85The As multiple quantum well active layer 106 is provided at a position corresponding to the antinode of the standing wave of the oscillation light in order to obtain a high stimulated emission probability. Conversely, the n-AlAs selectively oxidized layer 104 is provided at a position corresponding to a node of the standing wave of the oscillation light in order to reduce the diffraction loss of light. In the element of FIG. 1, as shown in FIG. 2, each element is provided at a position that becomes a node of the second standing wave as viewed from the active layer 106.
[0118]
In the surface emitting laser element of FIG. 1, after crystal growth, a square resist pattern having a side of 10 μm is formed by a known photolithography technique, and hydrogen ions are implanted using the resist pattern as a mask. Region 116 is formed. Next, alignment is performed on the hydrogen ion implantation region, and a square resist pattern having a side of 30 μm is formed again by a known photolithography technique, and p-Al is formed using a known dry etching technique._0.9Ga_0.1As / Al_0.15Ga_0.85N-Al from the surface of the As upper semiconductor distributed Bragg reflector 108_0.9Ga_0.1As / Al_0.15Ga_0.85Etching of each layer up to the middle of the As lower distributed semiconductor Bragg reflector 103 is performed to form a square mesa.
[0119]
Next, in a heated atmosphere containing water vapor, the n-AlAs selectively oxidized layer 104 is selectively oxidized in a direction parallel to the substrate from the etching end face toward the center of the mesa, leaving a non-oxidized region 114 in the center. The selective oxidation region 115 is formed around the mesa. Here, one side of the non-oxidized region 114 was 3 μm. As described above, the non-oxidation (conduction) region 114 in the electron passage is formed to have a relatively small area with respect to 10 μm on one side of the ion non-injection conduction region 117 in the hole passage. Note that the selective oxidation structure including the non-oxidized region 114 and the selective oxidation region 115 is provided as a high-order transverse mode suppression structure.
[0120]
Next, a vapor-phase chemical deposition method (CVD method) is used to form SiO on the entire wafer surface.₂After the layer 109 was formed, the insulating resin 110 was spin-coated by aligning with the center of the mesa and removing the insulating resin on the mesa. Next, the insulating resin removal part SiO₂Layer 109 was removed. Next, a 10 μm square resist pattern was formed in a region to be a light emitting portion on the mesa, and p-side electrode material was deposited. Next, the electrode material of the light emitting part was lifted off, and the p-side electrode 111 was formed. Next, after polishing the back surface of the n-GaAs substrate 101, the n-side electrode 112 was provided on the back surface of the substrate 101 by vapor deposition. Next, ohmic conduction was established between the electrodes 111 and 112 by annealing.
[0121]
In the surface emitting laser element of FIG._0.9Ga_0.1As / Al_0.15Ga_0.85The As upper semiconductor distributed Bragg reflector 108 is provided with a hole confinement structure including an ion-implanted high resistance region 116 and an ion non-implant conduction region 117, and n-Al_0.9Ga_0.1As / Al_0.15Ga_0.85The As lower semiconductor distributed Bragg reflector 103 includes a higher-order transverse mode suppression structure including a selective oxidation region 115 and a non-oxidation region 114, and the area of the non-oxidation region 114 in the higher-order lateral mode suppression structure is positive. It is provided smaller than the area of the ion non-implanting conduction region 117 in the hole confinement structure.
[0122]
In the conventional surface emitting laser element, in order to stably obtain a single fundamental transverse mode oscillation, the area of the non-oxidized region in the p-conductivity type distributed Bragg reflector is reduced. And the heat generation of the element due to the increase in resistance.
[0123]
However, the element of the first embodiment is n-Al._0.9Ga_0.1As / Al_0.15Ga_0.85The oscillation transverse mode is controlled by the high-order transverse mode suppression structure provided in the As lower semiconductor distributed Bragg reflector 103, and the resistance of the n-type distributed Bragg reflector is lower than that of the p-conductivity distributed Bragg reflector. Therefore, single fundamental transverse mode oscillation can be obtained up to a high output without increasing the resistance of the element.
[0124]
However, since electrons have a higher mobility than holes, it is difficult to effectively confine the carrier injection region at the center of the mesa by the high-order transverse mode suppression structure provided in the n-type distributed Bragg reflector. There is a problem that the carrier diffuses to the mesa side surface and the light emission efficiency is lowered by the non-radiative recombination level of the mesa side surface. In order to confine holes with high confinement efficiency to the center of the mesa and to achieve high internal quantum efficiency, a hole confinement structure is provided by ion implantation. In addition, by selecting a large area of the ion non-injection conduction region in the hole confinement structure within a range where high internal quantum efficiency can be obtained, the oscillation region can be expanded and the resistance of the element can be prevented from being increased. it can.
[0125]
Further, in the surface emitting laser element of this structure, since the transverse mode is confined by the selective oxidation structure having a large refractive index difference, single fundamental transverse mode oscillation can be stably obtained even when the driving state of the element is changed. I can do things.
[0126]
As described above, the element of the first embodiment can oscillate in a single fundamental mode up to a high output, and the output saturation point due to heat is higher than that of the conventional element, so that a high output can be obtained. It was. Further, the element has a low resistance, and high-speed modulation was possible.
[0127]
In the first embodiment, the position of the high-order transverse mode suppression structure is the position of the standing wave node closest to the active layer in the distributed Bragg reflector. Also good. Further, the position of the high-order transverse mode suppression structure can be provided at an arbitrary position such as an antinode other than the standing wave node.
[0128]
(Second embodiment)
FIG. 3 is a diagram showing a surface emitting laser element according to the second embodiment. The surface emitting laser element of FIG. 3 is a 1.3 μm band surface emitting laser element having a GaInNAs / GaAs multiple quantum well structure as an active layer. The surface emitting laser element of FIG. 3 is obtained by crystal growth by MOCVD as in the surface emitting laser element of the first embodiment, and dimethylhydrazine (DMHy) is used as the nitrogen source of the active layer. .
[0129]
The surface emitting laser element shown in FIG. 3 is grown by the same crystal growth method as in the first embodiment. Specifically, the device of FIG. 3 includes an n-GaAs buffer layer 202 and an n-Al on an n-GaAs substrate 201._0.9Ga_0.136 cycles of n-Al with one pair of As / GaAs_0.9Ga_0.1An As / GaAs lower semiconductor distributed Bragg reflector 203, a non-doped GaAs resonator spacer 205, a non-doped GaInNAs / GaAs multiple quantum well active layer 206, a non-doped GaAs resonator spacer 207, and a p-Al_0.9Ga_0.1As / GaAs upper semiconductor Bragg reflector 208 and n-Al_0.9Ga_0.1A 20-period upper semiconductor distributed Bragg reflector composed of an As / GaAs upper semiconductor distributed Bragg reflector 219 is formed by sequentially crystal growth. In addition, in the GaAs layer serving as the outermost surface layer of the upper distributed Bragg reflector, a p-GaAs contact layer (not shown) having a high concentration of carbon doping as a p-type dopant in the vicinity of the surface is provided.
[0130]
Further, in each layer constituting the upper semiconductor distributed Bragg reflectors 219 and 208 and the lower semiconductor multi-distributed Bragg reflector 203, the phase change of light in each layer with respect to the oscillation wavelength is π / 2 as in the first embodiment. The layer thickness is as follows. The same applies to the following embodiments.
[0131]
N-Al_0.9Ga_0.1The As / GaAs bottom distributed Bragg reflector 203 is provided with an n-AlAs selectively oxidized layer 204 having a thickness of 30 nm. The n-AlAs selectively oxidized layer 204 is selectively oxidized by selective oxidation. The region includes an oxidized region 215 and a non-oxidized region 214 that is not oxidized. P-Al_0.9Ga_0.1In the As / GaAs upper semiconductor Bragg reflectors 208 and 219, an ion implantation high resistance region 216 and an ion non-implant conduction region 217 are provided.
[0132]
FIG. 4 is a diagram showing in detail the periphery of the resonance region 213 in the surface emitting laser element of FIG. 3 together with the standing wave of the oscillation light. FIG. 4 shows a resonance region 213 composed of a non-doped GaAs resonator spacer 205, a non-doped GaInNAs / GaAs multiple quantum well active layer 206, and a non-doped GaAs resonator spacer 207, and n-Al._0.9Ga_0.1An n-Al composed of an As lower semiconductor distributed Bragg reflector low refractive layer 203a, an n-AlAs selectively oxidized layer 204, and an n-GaAs lower semiconductor distributed Bragg reflector high refractive layer 203b._0.9Ga_0.1A structure of one period of the As / GaAs lower semiconductor distributed Bragg reflector 203 and p-Al_0.9Ga_0.1As upper semiconductor distributed Bragg reflector low refractive layer 208a, p-GaAs upper semiconductor distributed Bragg reflector high refractive layer 208b, tunnel junction 218, n-GaAs upper semiconductor distributed Bragg reflector high refractive layer 219b, n- Al_0.9Ga_0.1A structure comprising an As upper semiconductor distributed Bragg reflector low refractive layer 219a is shown.
[0133]
Also, between the p-GaAs upper semiconductor distributed Bragg reflector high refractive layer 208b and the n-GaAs upper semiconductor distributed Bragg reflector high refractive layer 219b, p⁺⁺-GaAs layer and n⁺⁺A tunnel junction 218 made of a −GaAs layer is provided. n-Al provided with n-AlAs selectively oxidized layer 204_0.9Ga_0.1The thickness of the As lower semiconductor distributed Bragg reflector low-refractive layer 203a is such that the phase change of the oscillation light in each region including the AlAs selectively oxidized layer is 3π / 2 so as to satisfy the phase condition of the Bragg reflector. It has become. Similarly, the tunnel junction 218, the p-GaAs upper semiconductor distributed Bragg reflector high-refractive layer 208b, and the n-GaAs upper semiconductor distributed Bragg reflector high-refractive layer 219b also have a light phase change of 3π / in these layers. The thickness is 2.
[0134]
In the element of the second embodiment, as in the first embodiment, the positive ion implantation region 216 and the non-ion implantation conduction region 217 surrounded by the ion implantation high resistance region 216 are positively implanted by hydrogen ion implantation. After forming the hole constriction structure, a mesa is formed in the same manner. Next, the selective oxidation region 215 and the non-oxidation region 214 are formed by selectively oxidizing the n-AlAs selectively oxidized layer 204. Here, the area of the non-oxidation (conduction) region 214 is formed relatively smaller than the area of the ion non-implantation conduction region 217. Specifically, the length of one side of the non-ion-implanted conduction region 217 is 10 μm, and the length of one side of the non-oxidized region 214 is 5 μm. The selective oxidation structure composed of the non-oxidized region 214 and the selective oxidation region 215 is provided as a high-order transverse mode suppression structure.
[0135]
Here, since the surface emitting laser element of the second embodiment has a long oscillation wavelength, the thickness of the distributed Bragg reflector is thicker than that of the element of the 0.85 μm band and the like is high near the active layer. In order to provide the resistance region, a larger acceleration voltage of hydrogen ions is required. Therefore, in the surface emitting laser element of the second embodiment, a high resistance region is provided in the region near the active layer by an acceleration voltage larger than usual.
[0136]
As another manufacturing method, n-Al_0.9Ga_0.1During crystal growth of the As / GaAs upper distributed Bragg reflector 219, the growth is interrupted and a resist pattern is formed. Then, hydrogen ion implantation is performed to provide an ion implantation high resistance region 216 to remove the resist and remove the growth surface. After cleaning, the remaining n-Al again_0.9Ga_0.1Crystal growth of the As upper distributed Bragg reflector 219 can also be performed. With such a manufacturing method, it is possible to easily provide a high resistance region with a relatively low acceleration voltage. At this time, if the ion-implanted high resistance region 216 is formed by oxygen ion implantation instead of hydrogen ions, the effect of reducing the resistance of the ion implantation region due to the temperature during growth is effectively reduced. .
[0137]
Next, as in the first embodiment, SiO₂After the insulating region 209 and the insulating region 210 are formed by the insulating resin 210, the p-side electrode 211 and the n-side electrode 212 are formed.
[0138]
The element of the second embodiment is similar to the element of the first embodiment in that n-Al_0.9Ga_0.1As / Al_0.15Ga_0.85The lateral mode is controlled by a high-order transverse mode suppression structure provided in the As lower semiconductor distributed Bragg reflector 203, and the resistance of the n-type distributed Bragg reflector is lower than that of the p-conductivity distributed Bragg reflector. Therefore, it is possible to suppress high-order transverse mode oscillation without increasing the resistance.
[0139]
In fact, the surface emitting laser element of FIG. 3 has a low element resistance like the element of Example 1, can obtain a high output while maintaining a single fundamental transverse mode oscillation, and can operate at a higher speed. It was. Further, since the transverse mode confinement is performed by the selective oxidation structure, it is possible to stably obtain a single fundamental transverse mode oscillation even when the driving state of the element is changed.
[0140]
Most of the upper and lower distributed Bragg reflectors are composed of n-semiconductor distributed Bragg reflectors with less absorption loss than p-semiconductor distributed Bragg reflectors, and have characteristics such as high slope efficiency and low oscillation threshold current. Thus, a long-wavelength surface emitting laser device having excellent characteristics can be obtained. In the present invention, as in the second embodiment, a surface emitting laser element structure having a tunnel junction can be provided.
[0141]
(Third embodiment)
FIG. 5 is a diagram showing a surface emitting laser element according to a third embodiment. The surface emitting laser element of FIG._0.15Ga_0.85This is a 0.85 μm band surface emitting laser device having an As multiple quantum well structure as an active layer. The surface emitting laser element shown in FIG. 5 is configured by inverting the upper and lower conductive types sandwiching the active layer with respect to the element of the first embodiment, and the same configuration as that of the first embodiment except for this point. It has become. The structure will be described below.
[0142]
Specifically, the element of FIG. 5 includes a p-GaAs buffer layer 302 and a p-Al on a p-GaAs substrate 301._0.9Ga_0.1As / Al_0.15Ga_0.8536 cycles of p-Al with one pair of As_0.9Ga_0.1As / Al_0.15Ga_0.85As lower semiconductor distributed Bragg reflector 303 and non-doped Al_0.15Ga_0.85As resonator spacer 305 and GaAs / Al_0.15Ga_0.85As multiple quantum well active layer 306 and non-doped Al_0.15Ga_0.85A resonance region 313 composed of an As resonator spacer 307 and 20 cycles of n-Al_0.9Ga_0.1As / Al_0.15Ga_0.85The As upper semiconductor distributed Bragg reflector 308 is formed by sequentially growing crystals. N-Al_0.9Ga_0.1As / Al_0.15Ga_0.85In the As upper distributed Bragg reflector 308, an n-AlAs selective oxidation layer 304 having a thickness of 30 nm is provided, and the n-AlAs selective oxidation layer 304 is selectively oxidized region 315 oxidized by selective oxidation. And a non-oxidized region 314 that has not been oxidized. N-Al_0.9Ga_0.1As / Al_0.15Ga_0.85As upper semiconductor Bragg reflector 308, resonator region 313, and p-Al_0.9Ga_0.1As / Al_0.15Ga_0.85In the As lower semiconductor Bragg reflector 303, an ion implantation high resistance region 316 formed by hydrogen ion implantation and an ion non-implant conduction region 317 surrounded by the ion implantation high resistance region 316 are provided. .
[0143]
FIG. 6 is a diagram showing in detail the periphery of the resonance region 313 of the surface emitting laser element of FIG. FIG. 6 shows the resonance region 313 and p-Al._0.9Ga_0.1As lower semiconductor distributed Bragg reflector low refractive layer 303a and p-Al_0.15Ga_0.85P-Al comprising As lower semiconductor distributed Bragg reflector high refractive layer 303b_0.9Ga_0.1As / Al_0.15Ga_0.85The structure of one period of the As lower semiconductor distributed Bragg reflector 303, and n-Al_0.9Ga_0.1As upper semiconductor distributed Bragg reflector low refractive layer 308a, n-AlAs selectively oxidized layer 304, and n-Al_0.15Ga_0.85N-Al composed of As upper semiconductor distributed Bragg reflector high refractive layer 308b_0.9Ga_0.1As / Al_0.15Ga_0.85The structure of one period of the As upper semiconductor distributed Bragg reflector 308 is shown.
[0144]
Here, in the surface emitting laser element of FIG. 5, n-Al in contact with the resonance region as shown in FIG._0.9Ga_0.1An n-AlAs selectively oxidized layer 304 is provided in the As upper semiconductor distributed Bragg reflector low refractive layer 308a. Further, n-AlAs provided with an n-AlAs selective oxidation layer 304 is provided._0.9Ga_0.1Only the thickness of the As upper semiconductor distributed Bragg reflector low-refractive layer 303a is such that the phase change of the oscillation light in each region including the n-AlAs selectively oxidized layer 304 is 3π / 2. GaAs / Al_0.15Ga_0.85The As multiple quantum well active layer 306 is provided at a position where an antinode of standing wave of oscillation light is present, and the n-AlAs selectively oxidized layer 304 is provided at a position serving as a node. The element has a 1λ resonator structure.
[0145]
In the element of the third embodiment, as in the first embodiment, a hole confinement structure including an ion implantation high resistance region 316 and an ion non-implant conduction region 317 is formed by hydrogen ion implantation, and then a mesa is formed. Forming. Next, the n-AlAs selectively oxidized layer 304 is selectively oxidized to form a high-order transverse mode suppression structure including a selective oxidation region 315 and a non-oxidation (conduction) region 314. Here, the area of the non-oxidation (conduction) region 314 is formed relatively smaller than the area of the ion non-implantation conduction region 317. Specifically, the length of one side of the non-ion-implanted conduction region 317 is 10 μm, and the length of one side of the non-oxidized region 314 is 3 μm.
[0146]
And in this 3rd Example, similarly to the 1st Example, it is SiO.₂After forming the insulating region with the insulating layer 309 and the insulating resin 310, the n-side electrode 311 and the p-side electrode 312 are formed.
[0147]
The surface-emitting laser element shown in FIG. 5 had a low element resistance, a high output while maintaining a single fundamental transverse mode oscillation, and a high-speed operation as well as the element of Example 1. . Further, since the transverse mode confinement is performed by the selective oxidation structure, it is possible to stably obtain a single fundamental transverse mode oscillation even when the driving state of the element is changed.
[0148]
In this way, an element can be formed using a p-conducting semiconductor substrate, with the substrate side being p-conductive type and the surface side being n-conductive type with respect to the resonance region.
[0149]
(Fourth embodiment)
FIG. 7 is a view showing a surface emitting laser element according to a fourth embodiment. The surface emitting laser element of FIG._0.15Ga_0.85This is a 0.85 μm band surface emitting laser device having an As multiple quantum well structure as an active layer. The surface emitting laser element shown in FIG. 7 has a so-called intracavity contact structure in which an electrode for injecting carriers is provided in a semiconductor layer inside the element. The structure will be described below according to the manufacturing process.
[0150]
The surface emitting laser element shown in FIG. 7 is obtained by performing crystal growth by MOCVD as in the first embodiment. Specifically, the device of FIG. 7 includes an n-GaAs buffer layer 402 and a 36-cycle n-Al on an n-GaAs substrate 401._0.9Ga_0.1As / Al_0.15Ga_0.85As lower semiconductor distributed Bragg reflector 403, resonance region 413, 20 periods of non-doped Al_0.9Ga_0.1As / Al_0.15Ga_0.85The As upper semiconductor distributed Bragg reflector 408 is formed by sequentially growing crystals. Here, the resonance region 413 is non-doped GaAs / Al._0.15Ga_0.85As multiple quantum well active layer 407, Al_0.15Ga_0.85And an As resonator spacer layer 406.
[0151]
N-Al_0.9Ga_0.1As / Al_0.15Ga_0.85In the As lower semiconductor distributed Bragg reflector 403, an n-AlAs selective oxidation layer 404 is provided, and the selective oxidation layer 404 is oxidized with a selective oxidation region 415 oxidized by selective oxidation. And non-oxidized regions 414 that are not present. Al_0.15Ga_0.85In the As resonator spacer layer 406, an ion implantation high resistance region 416 and an ion non-implant conduction region 417 are provided.
[0152]
FIG. 8 is a diagram showing in detail the periphery of the resonance region of the intracavity contact surface emitting laser element of FIG. That is, FIG. 8 shows the resonance region 413 and n-Al._0.9Ga_0.1As lower semiconductor distributed Bragg reflector low refractive layer 403a, n-AlAs selectively oxidized layer 404 and n-Al_0.15Ga_0.85N-Al with As lower semiconductor distributed Bragg reflector high refractive layer 403b_0.9Ga_0.1As / Al_{0 . 15}Ga_0.85Structure of one period of As lower semiconductor distributed Bragg reflector 403 and non-doped Al_0.9Ga_0.1As upper semiconductor distributed Bragg reflector low refractive layer 408a and non-doped Al_0.15Ga_0.85Non-doped Al with As upper semiconductor distributed Bragg reflector high refractive layer 408b_0.9Ga_0.1As / Al_0.15Ga_0.85The structure of one period of the As upper semiconductor distributed Bragg reflector 408 is shown.
[0153]
Where n-Al_0.9Ga_0.1In the As lower semiconductor distributed Bragg reflector low-refractive layer 403a, an n-AlAs selectively oxidized layer 404 with a thickness of 30 nm is provided as shown in FIG. The resonance region 413 is a non-doped Al in order from the substrate 401 side._0.15Ga_0.85As resonator spacer layer 406a, non-doped GaAs / Al_0.15Ga_0.85As multiple quantum well structure 407, non-doped Al_0.15Ga_0.85As spacer layer 406b, p-Al_0.15Ga_0.85As spacer layer 406c, p-Al_0.15Ga_0.85As contact / resonator spacer layer 406d, non-doped Al_0.15Ga_0.85An As resonator spacer layer 406e is formed by crystal growth.
[0154]
In the surface emitting laser element of FIG. 7, as shown in FIG. 8, an n-AlAs selectively oxidized layer 404 is provided._0.9Ga_0.1Only the layer thickness of the As lower semiconductor distributed Bragg reflector low-refractive layer 403a is determined by the n-AlAs selectively oxidized layer 404 and the n-Al._0.9Ga_0.1The phase change of the oscillation light in the As lower semiconductor distributed Bragg reflector low refractive layer 403a is adjusted to 3π / 2. Also, non-doped Al that forms the resonance region 413_0.15Ga_0.85As resonator spacer layers 406a and 406b, non-doped GaAs / Al_0.15Ga_0.85As multiple quantum well structure 407, p-Al_0.15Ga_0.85As resonator spacer layer 406c, p-Al_0.15Ga_0.85As contact layer / cavity spacer layer 406d, non-doped Al_0.15Ga_0.85The As resonator spacer layer 406e forms a 2λ resonator structure.
[0155]
Also, the active layer GaAs / Al_0.15Ga_0.85The As multiple quantum well structure 407 is provided at a position corresponding to the antinode of the standing wave of the oscillation light. Conversely, the n-AlAs selectively oxidized layer 404 is provided at a position corresponding to the node of the standing wave of the oscillation light in order to reduce the diffraction loss of light. In the element of FIG. 7, as shown in FIG. 8, an n-AlAs selectively oxidized layer 404 is provided at a position that becomes a node of the second standing wave when viewed from the active layer. P-Al_0.15Ga_0.85The As resonator spacer / contact layer 406d is provided at a position that becomes a node of a standing wave in order to reduce light absorption loss due to the semiconductor layer doped with a high concentration of p-type.
[0156]
As shown in FIG. 8, the surface emitting laser element shown in FIG. 7 is formed by the well-known photolithography technique and ion implantation technique, as shown in FIG._0.15Ga_0.85Hydrogen ion implantation was performed in the As resonator spacer 406 to provide a hole confinement structure including an ion implantation increased resistance region 416 and an ion non-implanted conduction region 417 surrounded by the ion implantation increased resistance region 416. Here, the length of one side of the ion non-implanting conduction region 417 was 10 μm.
[0157]
Next, using the photoengraving technique and the etching technique again, the ion non-implanted conduction region 417 is aligned and non-doped Al_0.9Ga_0.1As / Al_0.15Ga_0.85P-Al from the surface of the As upper distributed Bragg reflection 408_0.15Ga_0.85Each layer up to the surface of the As resonator spacer / contact layer 406d was removed by etching, and a square mesa with a side of 20 μm was formed as shown in FIG.
[0158]
Next, again using photolithography and etching techniques, n-Al_0.9Ga_0.1As / Al_0.15Ga_0.85Etching of each layer up to the middle of the As lower semiconductor distributed Bragg reflector 403 was performed to form a square mesa having a side of 40 μm as shown in FIG.
[0159]
Next, the n-AlAs selectively oxidized layer 404 is selectively oxidized to form a high-order transverse mode suppression structure including a selective oxidation region 415 and a non-oxidation (conduction) region 414. Here, the area of the non-oxidized region 414 is formed to be relatively smaller than the area of the ion non-implanted conduction region 417. Specifically, the length of one side of the ion non-implanted conduction region 417 is 10 μm, and the length of one side of the non-oxidized region 414 is 3 μm.
[0160]
Next, a vapor-phase chemical deposition method (CVD method) is used to form SiO on the entire wafer surface.₂After the layer 409 is formed, a square resist opening pattern having a diameter of 45 μm is formed by aligning with the central part of the mesa, and the opening SiO 2₂Was removed. Next, p-Al_0.15Ga_0.85On the As resonator spacer / contact layer 406d, a 20 μm resist pattern was formed by aligning with a mesa, and a p-side electrode 411 was formed by vapor deposition and lift-off. Next, after polishing the back surface of the substrate 401, an n-side electrode 412 was provided on the back surface of the substrate 401 by vapor deposition. Next, both electrodes 411 and 412 were brought into ohmic conduction by annealing to obtain the element shown in FIG.
[0161]
In semiconductor materials, light absorption tends to become more prominent as doping increases, and the oscillation threshold current increases due to the effects of absorption loss due to highly doped layers and distributed Bragg reflectors, leading to a decrease in slope efficiency. It is done.
[0162]
On the other hand, in the case of the intracavity contact structure as in the fourth embodiment, it is necessary to dope the distributed Bragg reflector by injecting carriers through the contact layer provided in the resonator. The effect of light absorption can be reduced. In the element of the fourth embodiment, hole injection is performed through a contact layer provided in the resonator, and no p-conduction type distributed Bragg reflector is used. Therefore, a surface emitting laser element having a low oscillation threshold current and a large slope efficiency can be obtained.
[0163]
Further, the surface emitting laser element of FIG. 7 has a low element resistance like the element of the first embodiment, can obtain a high output while maintaining a single fundamental transverse mode oscillation, and can operate at a higher speed. Met. Further, since the transverse mode confinement is performed by the selective oxidation structure, it is possible to stably obtain a single fundamental transverse mode oscillation even when the driving state of the element is changed.
[0164]
As described above, the configuration of the present invention can also be applied to the intracavity contact type surface emitting laser element.
[0165]
(Fifth embodiment)
FIG. 9 is a diagram showing a surface emitting laser element according to a fifth embodiment. The surface emitting laser element of FIG. 9 is a 1.3 μm band surface emitting laser element having a GaInNAs / GaAs multiple quantum well structure as an active layer. The surface emitting laser element shown in FIG. 9 has an intracavity contact structure in which an electrode for injecting carriers is provided in a semiconductor layer inside the element. In the element of the fifth embodiment, the position of the n-AlAs selectively oxidized layer is provided in the resonance region, and the upper reflecting mirror is made of a dielectric material (MgF₂) And a semiconductor material (ZnSe). The structure will be described below according to the manufacturing process.
[0166]
The intracavity contact type surface emitting laser device of FIG. 9 grows a crystal of an n-GaAs buffer layer 502 on an n-GaAs substrate 501, and then has 36 cycles of n-type with one AlAs / GaAs pair as one cycle. An AlAs / GaAs lower semiconductor distributed Bragg reflector 503, a resonance region 513, and a p-GaAs contact layer 506f are formed by crystal growth.
[0167]
Here, the resonance region 513 includes a non-doped GaInNAs / GaAs multiple quantum well structure 507 and a GaAs resonator spacer layer 506. In the n-GaAs resonator spacer layer 506, n-AlAs selective oxidation is performed. A layer 504 is provided. The selectively oxidized layer 504 includes a selectively oxidized region 515 that has been oxidized by selective oxidation and a non-oxidized region 514 that has not been oxidized. Further, in the GaAs resonator spacer layer 506, an ion implantation high resistance region 516 and an ion non-implant conduction region 517 are provided.
[0168]
FIG. 10 is a diagram showing in detail the periphery of the resonance region 513 in the intracavity contact surface emitting laser element of FIG. That is, FIG. 10 shows one of the n-AlAs / GaAs lower semiconductor distributed Bragg reflector 503 including the n-AlAs lower semiconductor distributed Bragg reflector low refractive layer 503a and the n-GaAs lower semiconductor distributed Bragg reflector high refractive layer 503b. A structure for a period and a resonance region 513 provided thereon are shown.
[0169]
In the intracavity contact surface emitting laser element of FIG. 9, after crystal growth of the n-AlAs / GaAs lower distributed Bragg reflector 503, as shown in FIG. 10, the n-GaAs resonator spacer layer 506a, n− AlAs selectively oxidized layer 504, n-GaAs resonator spacer layer 506b, non-doped GaAs resonator spacer layer 506c, non-doped GaInNAs / GaAs multiple quantum well structure 507, non-doped GaAs resonator spacer layer 506d, p-GaAs resonator spacer layer 506e The crystal region of the resonance region 513 and the p-GaAs contact layer 506f are grown. Here, the resonance region 513 has a 2.5λ resonator structure.
[0170]
In the surface emitting laser element shown in FIG. 9, after each layer is crystal-grown, as shown in FIG. 10, in the GaAs resonator spacer layer 506, as in the first embodiment, as shown in FIG. Then, hydrogen ion implantation was performed to provide a hole confinement structure including an ion implantation high resistance region 516 and an ion non-implantation conduction region 517 surrounded by the ion implantation high resistance region 516. Here, the length of one side of the ion non-implanting conduction region 517 was set to 15 μm. As in the fifth embodiment, in an element having an upper semiconductor distributed Bragg reflector made of a dielectric material, hydrogen ions can be implanted before forming the dielectric upper distributed Bragg reflector, so that the implantation depth is shallow. Therefore, it is possible to provide a high resistance region easily and with good control. Therefore, the configuration of the fifth embodiment is particularly suitable for a long wavelength surface emitting laser element.
[0171]
Next, halfway of the n-GaAs resonator spacer 506a was removed by etching using a known photolithography technique and etching technique to form a square mesa having a thickness of 50 μm.
[0172]
Next, the n-AlAs selectively oxidized layer 504 is selectively oxidized to form a high-order transverse mode suppression structure including a selective oxidation region 515 and a non-oxidation (conduction) region 514. Here, the area of the non-oxidized region 514 is formed relatively smaller than the area of the non-ion-implanted conduction region 517. Specifically, the length of one side of the non-ion-implanted conduction region 517 is 15 μm, and the length of one side of the non-oxidized region 514 is 5 μm.
[0173]
Next, SiO₂After the formation of the insulating film 509, the p-GaAs contact layer 506f corresponding to the resonance region was removed by etching in order to reduce absorption loss. At this time, wet etching or the like is suitable for etching the GaAs contact layer 506f, and by providing a GaInP etching stop layer or the like under the GaAs contact layer 506f, the etching can be performed with good controllability. Next, ZnSe / MgF₂5 periods of ZnSe / MgF₂An upper distributed Bragg reflector 508 is formed by electron beam evaporation. Next, ZnSe / MgF₂After the upper distributed Bragg reflector 508 was etched into a mesa shape by dry etching, the p-side electrode 511 and the n-side electrode 512 were formed. Next, both electrodes 511 and 512 were subjected to ohmic conduction by annealing, and the element shown in FIG. 9 was obtained.
[0174]
In semiconductor materials, light absorption tends to become more prominent when doping increases, and the oscillation threshold current increases due to the effects of absorption loss due to highly doped layers and distributed Bragg reflectors, and slope efficiency tends to decrease. In particular, in a p-type semiconductor material, light absorption tends to increase due to absorption between valence bands as the wavelength becomes longer.
[0175]
On the other hand, in the case of the intracavity contact structure as in the fifth embodiment, it is necessary to use a distributed Bragg reflector made of a semiconductor material by injecting carriers through a contact layer provided in the resonator. And the effect of light absorption can be greatly reduced. As described above, it is possible to obtain a long-wavelength surface emitting laser element having a particularly low oscillation threshold current and a large slope efficiency.
[0176]
In addition, the surface emitting laser element of FIG. 9 has a low element resistance, can obtain a high output while maintaining single fundamental transverse mode oscillation, and can operate at a higher speed. Further, since the transverse mode confinement is performed by the selective oxidation structure, it is possible to stably obtain a single fundamental transverse mode oscillation even when the driving state of the element is changed.
[0177]
As described above, the upper distributed Bragg reflector can be configured using a dielectric material or the like in addition to the semiconductor. In the fifth embodiment, an upper distributed Bragg reflector using a combination of a dielectric and a semiconductor is used. However, an upper distributed Bragg reflector can be configured using only a dielectric material. . Since the dielectric material has a smaller absorption loss than the semiconductor material, a surface emitting laser element having a low oscillation threshold current and a high slope efficiency can be obtained by using the dielectric material.
[0178]
(Sixth embodiment)
FIG. 11 is a diagram showing a surface emitting laser element according to the sixth embodiment. The surface emitting laser element of FIG. 11 is a 1.3 μm band surface emitting laser element having a GaInNAs / GaAs multiple quantum well structure as an active layer. The surface emitting laser element shown in FIG. 11 has an intracavity contact structure in which an electrode for injecting carriers is provided in a semiconductor layer inside the element. In the element of the sixth embodiment, both the p-side electrode and the n-side electrode are provided on the surface side of the substrate. The structure will be described below according to the manufacturing process.
[0179]
The surface emitting laser element of FIG. 11 is obtained by growing a non-doped GaAs buffer layer 602 on a semi-insulating GaAs substrate 601 and then 36 non-doped AlAs / GaAs lower semiconductor distributed Braggs with one AlAs / GaAs pair as one period. Reflector 603, resonance region 613, Al_0.8Ga_0.220 periods of non-doped Al with one As / GaAs pair_0.8Ga_0.2The As / GaAs upper semiconductor distributed Bragg reflector 608 is formed by crystal growth.
[0180]
Here, the resonance region 613 includes a non-doped GaInNAs / GaAs multiple quantum well structure 607 and a GaAs resonator spacer layer 606. In the n-GaAs resonator spacer layer 606, n-AlAs selective oxidation is performed. A layer 604 is provided. The selectively oxidized layer 604 includes a selectively oxidized region 615 that has been oxidized by selective oxidation and a non-oxidized region 614 that has not been oxidized. Further, in the GaAs resonator spacer layer 606, an ion implantation high resistance region 616 and an ion non-implant conduction region 617 are provided.
[0181]
FIG. 12 is a diagram showing in detail the periphery of the resonance region 613 in the surface emitting laser element of FIG. That is, FIG. 12 shows one period of the non-doped AlAs / GaAs lower semiconductor distributed Bragg reflector 603 by the non-doped AlAs lower semiconductor distributed Bragg reflector low-refractive layer 603a and the non-doped GaAs lower semiconductor distributed Bragg reflector high-refractive layer 603b. Structure, resonant region 613 provided thereon, non-doped Al_0.8Ga_0.2Non-doped Al by As upper semiconductor distributed Bragg reflector low refractive layer 608a and non-doped GaAs upper semiconductor distributed Bragg reflector high refractive layer 608b_0.8Ga_0.2The structure of one period of the As / GaAs upper semiconductor distributed Bragg reflector 608 is shown.
[0182]
As shown in FIG. 12, in the intracavity contact type surface emitting laser element of FIG. 11, after crystal growth of the non-doped AlAs / GaAs lower distributed Bragg reflector 603, the n-GaAs contact layer / cavity spacer layer 606a, n -GaAs resonator spacer layer 606b, n-AlAs selectively oxidized layer 604, n-GaAs resonator spacer layer 606c, non-doped GaAs resonator spacer layer 606d, GaInNAs / GaAs multiple quantum well structure 607, non-doped GaAs resonator spacer layer 606e , P-GaAs resonator spacer layer 606f, p-GaAs contact / resonator spacer layer 606g, resonance region 613 by non-doped GaAs resonator spacer layer 606h, non-doped Al_0.8Ga_0.2An As / GaAs upper semiconductor distributed Bragg reflector 608 is crystal-grown.
[0183]
In the surface emitting laser element of FIG. 11, non-doped Al_0.8Ga_0.2After partial crystal growth of the As / GaAs upper semiconductor distributed Bragg reflector 608, the growth is interrupted, a resist pattern is formed, hydrogen ion implantation is performed, an ion implantation high resistance region 616, and ion implantation A hole confinement structure including an ion non-implanting conduction region 617 surrounded by the high resistance region 616 is provided. Here, the length of one side of the non-ion-implanting conduction region 617 is 15 μm. Thereafter, the resist is removed, the growth surface is cleaned, and the remaining non-doped Al is again formed._0.8Ga_0.2Crystal growth of the As / GaAs upper semiconductor distributed Bragg reflector 608 is performed. By using the manufacturing method as described above, the ion implantation depth can be reduced, so that the high resistance region can be easily provided with good control.
[0184]
Further, as another manufacturing method, after crystal growth of the element, deep ion implantation can be performed so as to reach the vicinity of the active layer with a high acceleration voltage. In addition, in an element such as a 0.85 μm band, the thickness of the distributed Bragg reflector is small corresponding to the fact that the oscillation wavelength is shorter than that of the present element, so that ion implantation is easily performed with a normal acceleration voltage. Things are possible.
[0185]
In the surface emitting laser element of the sixth embodiment, as shown in FIG. 12, a p-GaAs resonator spacer / contact layer 606g for conducting with the p-side electrode and an n-side electrode are in contact with each other. An n-GaAs resonator spacer / contact layer 606a is provided, and the surface of each contact layer is removed by etching as shown in FIG. 11, and the length of one side is 30 μm and 50 μm, respectively. A square mesa is formed.
[0186]
Next, the n-AlAs selectively oxidized layer 604 is selectively oxidized to form a high-order transverse mode suppression structure including a selective oxidation region 615 and a non-oxidation (conduction) region 614. Here, the area of the non-oxidized region 614 is formed to be relatively smaller than the area of the non-ion-implanted conduction region 617. Specifically, the length of one side of the non-ion-implanted conduction region 617 is 15 μm, and the length of one side of the non-oxidized region 614 is 5 μm. Next, a p-side electrode 611 and an n-side electrode 612 were provided to obtain the surface emitting laser element of FIG.
[0187]
In the element of the sixth embodiment, both the p-side electrode and the n-side electrode are provided on the contact layer provided in the resonator, and no carrier injection is performed via the semiconductor distributed Bragg reflector. It has a structure. Therefore, it is not necessary to perform impurity doping on the semiconductor distributed Bragg reflector for conduction, and light absorption loss due to free carrier absorption or the like can be reduced.
[0188]
The surface emitting laser element of FIG. 11 has a low element resistance and can provide a high output while maintaining a single fundamental transverse mode oscillation, similarly to the surface emitting laser element of the fifth embodiment, and can operate at a higher speed. Was also possible. Further, since the transverse mode confinement is performed by the selective oxidation structure, it is possible to stably obtain a single fundamental transverse mode oscillation even when the driving state of the element is changed. Thus, a long wavelength band intracavity contact type surface emitting laser device with particularly excellent performance could be obtained. As in the sixth embodiment, it is possible to adopt a configuration in which all the electrodes of the element are taken from the substrate surface.
[0189]
(Seventh embodiment)
FIG. 13 is a diagram showing a surface emitting laser element according to a seventh embodiment. The surface emitting laser element of FIG. 13 is a 670 nm band visible surface emitting laser element having a GaInP / AlGaInP multiple quantum well structure as an active layer. Further, the surface emitting laser element of FIG. 13 has an intracavity contact structure in which an electrode for injecting carriers is provided in a semiconductor layer inside the element. In the element of the seventh embodiment, as in the sixth embodiment, both the p-side electrode and the n-side electrode are all provided on the surface side of the substrate. The configuration is different from that of the first embodiment. The structure will be described below according to the manufacturing process.
[0190]
The surface emitting laser element shown in FIG. 13 is manufactured by using the MOCVD method. Here, as the phosphorus (P) material, phosphine (PH₃) Is used. Further, dimethyl zinc (DMZn) is used as a p-type dopant in some layers. In the surface emitting laser element of FIG. 13, after growing a non-doped GaAs buffer layer 702 on a semi-insulating GaAs substrate 701, Al_0.9Ga_0.1As / Al_0.5Ga_0.556 periods of non-doped Al with one pair of As_0.9Ga_0.1As / Al_0.5Ga_0.5As lower semiconductor distributed Bragg reflector 703, resonant region 713, p- (Al_0.5Ga_0.5)_0.5In_0.5A P contact layer 706g is crystal-grown.
[0191]
Here, the resonance region 713 is non-doped GaInP / (Al_0.5Ga_0.5)_0.5In_0.5P multiple quantum well structure 707 and (Al_0.5Ga_0.5)_0.5In_0.5P resonator spacer layer 706. Non-doped Al_0.9Ga_0.1As / Al_0.5Ga_0.5In the As lower distributed Bragg reflector 703, a non-doped AlAs selective oxidation layer 704 is provided. The selective oxidation layer 704 includes a selective oxidation region 715 oxidized by selective oxidation and a non-oxidized non-oxidized region 715. An oxidation region 714 is formed. Also, (Al_0.5Ga_0.5)_0.5In_0.5In the P resonator spacer layer 706, an ion implantation high resistance region 716 and an ion non-implant conduction region 717 are provided.
[0192]
FIG. 14 is a diagram showing in detail the periphery of the resonance region 713 in the surface emitting laser element of FIG. That is, FIG. 14 shows non-doped Al._0.9Ga_0.1As lower semiconductor distributed Bragg reflector low refractive index layer 703a and non-doped Al_0.5Ga_{0 . 5}Non-doped Al with As lower semiconductor distributed Bragg reflector high refractive layer 703b_0.9Ga_0.1As / Al_0.5Ga_0.5A structure of one period of the As lower semiconductor distributed Bragg reflector 703, a resonance region 713 provided thereon, and a p-GaAs contact layer 706g are shown.
[0193]
The non-doped AlAs selectively oxidized layer 704 is made of non-doped Al._0.9Ga_0.1The As lower semiconductor distributed Bragg reflector is provided at a position corresponding to the node of the standing wave of the oscillation light closest to the active layer side in the low refractive index layer 703a. Note that the thickness of the non-doped AlAs selectively oxidized layer 704 is 20 nm.
[0194]
In the surface emitting laser element of FIG. 13, non-doped Al_0.9Ga_0.1As / Al_0.5Ga_0.5After crystal growth of the As lower distributed Bragg reflector 703, as shown in FIG._0.5Ga_0.5)_0.5In_0.5P resonator spacer layer 706a, n- (Al_0.5Ga_0.5)_0.5In_0.5P contact layer / resonator spacer layer 706b, n- (Al_0.5Ga_0.5)_0.5In_0.5P resonator spacer layer 706c, non-doped (Al_0.5Ga_0.5)_0.5In_0.5P resonator spacer layer 706d, non-doped GaInP / (Al_0.5Ga_0.5)_0.5In_0.5P multiple quantum well structure 707, non-doped (Al_0.5Ga_0.5)_0.5In_0.5P resonator spacer layer 706e, p- (Al_0.5Ga_0.5)_0.5In_0.5The P resonator spacer layer 706f and the p-GaAs contact layer 706g are crystal-grown. Here, the resonator structure is a 3λ structure.
[0195]
As shown in FIG. 10, the surface emitting laser element shown in FIG. 13 is made of (Al) by the well-known photolithography technique and ion implantation technique, as in the fifth embodiment, after crystal growth of each layer._0.5Ga_0.5)_0.5In_0.5Hydrogen ion implantation was performed in the P resonator spacer layer 706 to provide a hole confinement structure including an ion implantation high resistance region 716 and an ion non-implant conduction region 717 surrounded by the ion implantation high resistance region 716. . Here, the length of one side of the ion non-implanting conduction region 717 was set to 10 μm.
[0196]
As in the seventh embodiment, in an element having an upper semiconductor distributed Bragg reflector made of a dielectric material, hydrogen ions can be implanted before forming the dielectric upper distributed Bragg reflector, so that the implantation depth is shallow. Therefore, it is possible to provide a high resistance region easily and with good control.
[0197]
Next, as shown in FIG. 13, a two-step square mesa structure having side lengths of 30 μm and 50 μm was formed by a known photolithography technique and a known dry etching technique, respectively. Here, the upper mesa is formed by etching up to the surface of the p-GaAs contact layer 706g. The lower mesa is non-doped Al_0.9Ga_0.1As / Al_0.5Ga_0.5It is formed by etching part of the As lower distributed Bragg reflector 703.
[0198]
Next, the non-doped-AlAs selectively oxidized layer 704 is selectively oxidized to form a high-order transverse mode suppression structure composed of a selective oxidation region 715 and a non-oxidation region 714. Here, the area of the non-oxidized region 714 is formed relatively smaller than the area of the ion non-implanted conduction region 717. Specifically, the length of one side of the non-ion-implanted conduction region 717 is 10 μm, and the length of one side of the non-oxidized region 714 is 3 μm.
[0199]
Next, in order to reduce absorption loss, the p-GaAs contact layer 706g corresponding to the resonance region was removed by etching. Next, using an electron beam evaporation method, TiO₂/ SiO₂7 periods of TiO with one pair of₂/ SiO₂An upper dielectric distributed Bragg reflector 708 was deposited and processed into a mesa shape using a known dry etching technique as shown in FIG. Next, the p-side electrode electrode 711 and the n-side electrode electrode 712 were formed to obtain the surface emitting laser element of FIG.
[0200]
In the surface emitting laser element of FIG. 13, carriers are injected by two types of electrodes 711 and 712 provided on the substrate surface, and non-doped Al_0.9Ga_0.1As / Al_0.5Ga_0.5The area of the non-oxidized region 714 forming the higher-order transverse mode suppression structure provided in the As lower distributed Bragg reflector 703 has a structure that does not affect the electrical resistance.
[0201]
Further, in the element of the seventh embodiment, both the p-side and n-side electrodes are provided on the contact layer provided in the resonator, and carriers are injected through the semiconductor distributed Bragg reflector. I can't. Accordingly, it is not necessary to dope impurities in the semiconductor distributed Bragg reflector, and light absorption loss due to free carriers or the like can be reduced. Also, the effect of reducing absorption loss can be obtained by using the upper distributed Bragg reflector as a dielectric material. Particularly in the visible band, it is necessary to reduce the area of the non-oxidized region in order to perform the single basic transverse mode control, and it is easy to increase the resistance and to be affected by heat generation. In the element, the non-oxidized region 714 having a small area is provided in a region that avoids the electron passage and the hole passage of the element, and the resistance increase due to the non-oxidized region 714 can be prevented.
[0202]
The surface emitting laser element of FIG. 13 has a low element resistance, can obtain a high output while maintaining single fundamental transverse mode oscillation, and can operate at a higher speed. Further, since the transverse mode confinement is performed by the selective oxidation structure, it is possible to stably obtain a single fundamental transverse mode oscillation even when the driving state of the element is changed. Thus, a visible band intracavity contact type surface emitting laser device having particularly excellent performance could be obtained.
[0203]
(Eighth embodiment)
FIG. 15 is a diagram showing a surface emitting laser element according to an eighth embodiment. The surface emitting laser element of FIG. 15 is a 1.3 μm band surface emitting laser element having a GaInNAsSb / GaAs multiple quantum well structure as an active layer. 15 has an intracavity contact structure in which an electrode for injecting carriers into a semiconductor layer inside the element is provided. The element of the eighth embodiment has a configuration in which a selective oxidation structure for performing oscillation transverse mode control is provided in a region other than the carrier conduction region. The structure will be described below.
[0204]
In the surface emitting laser element of FIG. 15, the structure of the resonance region 813 is similar to that of the element of the fourth embodiment, and in the fourth embodiment, n-Al_0.8Ga_0.2Instead of the selective oxidation structure by the n-AlAs selective oxidation layer provided in the As / GaAs lower semiconductor distributed Bragg reflector, the selection by the non-doped AlAs selective oxidation layer in the non-doped upper distributed Bragg reflector as described later. An oxide structure is provided. The active layer has a GaInNAsSb / GaAs multiple quantum well structure.
[0205]
15 includes an n-GaAs substrate 801, an n-GaAs buffer 802, and n-Al._0.8Ga_0.2As / GaAs lower semiconductor distributed Bragg reflector 803, resonant region 813, non-doped Al_0.8Ga_0.2An As / GaAs upper distributed Bragg reflector 808 is sequentially grown.
[0206]
Here, the resonance region 813 includes a non-doped GaInNAsSb / GaAs multiple quantum well structure 807 and a GaAs resonator spacer layer 806. Non-doped Al_0.8Ga_0.2In the As / GaAs upper distributed Bragg reflector 808, a non-doped AlAs selective oxidation layer 804 is provided, and the selective oxidation layer 804 is oxidized with a selective oxidation region 815 oxidized by selective oxidation. The non-oxidized region 814 is not formed. Also, in the GaAs resonator spacer layer 806 and n-Al_0.8Ga_0.2In a part of the As / GaAs lower distributed Bragg reflector 803, an ion implantation high resistance region 816 and an ion non-implant conduction region 817 are provided.
[0207]
FIG. 16 is a diagram showing in detail the resonance region of the surface emitting laser element of FIG. That is, FIG. 16 shows n-Al._0.8Ga_0.2N-Al by As lower semiconductor distributed Bragg reflector low refractive layer 803a and n-GaAs lower semiconductor distributed Bragg reflector high refractive layer 803b_0.8Ga_0.2One-cycle structure of As / GaAs lower semiconductor distributed Bragg reflector 803 and non-doped Al_0.8Ga_0.2Non-doped Al by As upper semiconductor distributed Bragg reflector low refractive layer 808a and non-doped GaAs upper semiconductor distributed Bragg reflector high refractive layer 808b_0.8Ga_0.2A structure of one period of the As / GaAs upper semiconductor distributed Bragg reflector 808 and a resonance region 813 provided therebetween are shown.
[0208]
The resonance region 813 is n-Al._0.8Ga_0.2After crystal growth of the As / GaAs lower semiconductor distributed Bragg reflector 803, a non-doped GaAs resonator spacer layer 806a, a non-doped GaInNAsSb / GaAs multiple quantum well structure 807, a non-doped GaAs spacer layer 806b, a p-GaAs spacer layer 806c, p A GaAs contact / resonator spacer layer 806d and a non-doped GaAs spacer layer 806e are formed by crystal growth. The resonance region has a 2λ resonator structure.
[0209]
Here, the non-doped AlAs selectively oxidized layer 804 is made of non-doped Al._0.8Ga_0.2In the As / GaAs upper distributed Bragg reflector 808, the first non-doped Al corresponding to the standing wave node of the oscillation light as seen from the resonance region 813 side._0.8Ga_0.2As upper semiconductor distributed Bragg reflector is provided in the low refractive layer 808a. The thickness of the non-doped AlAs selectively oxidized layer 804 is 20 nm. Further, a non-doped AlAs selective oxidation layer 804 provided with a non-doped AlAs_0.8Ga_0.2The thickness of the As upper semiconductor distributed Bragg reflector low-refractive layer 808a is selected from the non-doped AlAs selectively oxidized layer 804 and the non-doped Al._0.8Ga_0.2The phase change of the light in the As upper semiconductor distributed Bragg reflector low refractive layer 808a is adjusted to be 3π / 2.
[0210]
In the surface-emitting laser element of FIG. 15, after crystal growth of each layer, as in the fourth embodiment, the GaAs resonator spacer 806 and n-Al are formed by a known photolithography technique and ion implantation technique._0.8Ga_0.2Hydrogen ions are implanted into a part of the As / GaAs lower semiconductor distributed Bragg reflector 803, and includes an ion-implanted high resistance region 816 and an ion non-implant conduction region 817 surrounded by the ion-implanted high resistance region 816. A hole confinement structure was provided. Here, the length of one side of the non-ion-implanted conduction region 817 is 10 μm. In the surface emitting laser element of this eighth embodiment, deep ion implantation is performed so that hydrogen ions reach the vicinity of the active layer, particularly using a high acceleration voltage. In addition to this, as described above, ion implantation can be performed by providing a growth interruption.
[0211]
Next, using the photoengraving technique and the etching technique again, the ion non-implanted conduction region 817 is aligned and non-doped Al_0.8Ga_0.2Etching of each layer from the surface of the As / GaAs upper semiconductor distributed Bragg reflector 808 to the surface of the p-GaAs contact / resonator spacer layer 806d was performed, and a square mesa with a side of 20 μm was formed as shown in FIG. . Next, again using photolithography and etching techniques, non-doped Al_0.8Ga_0.2Etching of each layer up to the middle of the As / GaAs lower semiconductor distributed Bragg reflector 803 was performed, and a square mesa with a side of 40 μm was formed as shown in FIG.
[0212]
Next, the non-doped-AlAs selectively oxidized layer 804 is selectively oxidized to form a high-order transverse mode suppression structure composed of the selective oxidation region 815 and the non-oxidation region 814. Here, the area of the non-oxidized region 814 is formed relatively smaller than the area of the non-ion-implanted conduction region 817. Specifically, the length of one side of the ion non-implanted conduction region 817 is 10 μm, and the length of one side of the non-oxidized region 814 is 5 μm.
[0213]
Next, SiO₂An insulating film 809, a p-side electrode 811 and an n-side electrode 812 were formed to obtain the surface emitting laser element of FIG.
[0214]
15 has a structure in which no current is injected through the upper distributed Bragg reflector 808. The upper semiconductor distributed Bragg reflector 808 is non-doped, and a p-type distributed Bragg reflector is used. Absorption loss is small. Non-doped Al_0.8Ga_0.2The non-oxidized region 815 provided in the As / GaAs upper semiconductor distributed Bragg reflector 808 does not affect the resistance. Therefore, the element has a very low resistance.
[0215]
The surface emitting laser element of FIG. 15 has a low element resistance as described above, can obtain a high output while maintaining single fundamental transverse mode oscillation, and can operate at a higher speed. Further, since the transverse mode confinement is performed by the selective oxidation structure, it is possible to stably obtain a single fundamental transverse mode oscillation even when the driving state of the element is changed. Thus, a long wavelength band intracavity contact type surface emitting laser device with particularly excellent performance could be obtained.
[0216]
(Ninth embodiment)
FIG. 17 is a diagram showing a surface emitting laser element according to a ninth embodiment. The surface emitting laser element shown in FIG. 17 is a 1.3 μm band surface emitting laser element having a GaInNAs / GaAs multiple quantum well structure as an active layer. The surface emitting laser element shown in FIG. 17 has an intracavity contact structure in which an electrode for injecting carriers is provided in a semiconductor layer inside the element. Further, the element of the ninth embodiment has a structure in which a p-side electrode and an n-side electrode are provided on the surface of the substrate. The structure will be described below.
[0217]
17 includes a non-doped GaAs buffer layer 902, a non-doped AlAs / GaAs lower semiconductor distributed Bragg reflector 903, a resonance region 913, a non-doped Al layer on a semi-insulating GaAs substrate 901._0.8Ga_0.2The As / GaAs upper distributed Bragg reflector 908 is constructed by sequentially growing crystals.
[0218]
Here, the resonance region 913 includes a non-doped GaInNAs / GaAs multiple quantum well structure 907 and a GaAs resonator spacer layer 906. Non-doped Al_0.8Ga_0.2In the As / GaAs upper distributed Bragg reflector 908, a non-doped AlAs selective oxidation layer 904 is provided, and the selective oxidation layer 904 is oxidized with a selective oxidation region 915 oxidized by selective oxidation. And non-oxidized regions 914 that are not present. In the GaAs resonator spacer 906, an ion implantation high resistance region 916 and an ion non-implant conduction region 917 are provided.
[0219]
FIG. 18 is a diagram showing in detail the periphery of the resonance region 913 in the surface emitting laser element of FIG. That is, FIG. 18 shows one cycle of the non-doped AlAs / GaAs lower semiconductor distributed Bragg reflector 903 by the non-doped AlAs lower semiconductor distributed Bragg reflector low-refractive layer 903a and the non-doped GaAs lower semiconductor distributed Bragg reflector high-refractive layer 903b. Structure, resonant region 913 provided thereon, non-doped Al_0.8Ga_0.2Non-doped Al by As upper semiconductor distributed Bragg reflector low refractive layer 908a and non-doped GaAs upper semiconductor distributed Bragg reflector high refractive layer 908b_0.8Ga_0.2The structure of one period of the As / GaAs upper semiconductor distributed Bragg reflector 908 is shown.
[0220]
In the intracavity contact type surface emitting laser device of FIG. 17, after crystal growth of a non-doped AlAs / GaAs bottom distributed Bragg reflector 903, as shown in FIG. 18, a non-doped GaAs resonator spacer layer 906a, an n-GaAs contact are obtained. Layer / resonator spacer layer 906b, n-GaAs resonator spacer layer 906c, non-doped GaAs resonator spacer layer 906d, non-doped GaInNAs / GaAs multiple quantum well structure 907, non-doped GaAs resonator spacer layer 906e, p-GaAs resonator spacer layer 906f, p-GaAs contact layer / resonator spacer layer 906g, resonance region 913 by non-doped GaAs resonator spacer layer 906h, non-doped Al_0.8Ga_0.2An As / GaAs upper semiconductor distributed Bragg reflector 908 is crystal-grown. In this embodiment, in order to further reduce absorption loss due to free carriers, an n-GaAs contact layer / resonator spacer layer 906b is also provided at the position of the standing wave of the oscillation light. Here, as shown in FIG. 18, non-doped Al_0.8Ga_0.2In the As / GaAs upper semiconductor distributed Bragg reflector 908, a non-doped AlAs selectively oxidized layer 904 having a thickness of 30 nm is provided at a position corresponding to a node of a standing wave.
[0221]
In the surface emitting laser element of FIG. 17, non-doped Al_0.8Ga_0.2After partial crystal growth of the As / GaAs upper semiconductor distributed Bragg reflector 908, the growth is interrupted, a resist pattern is formed, hydrogen ion implantation is performed, an ion implantation high resistance region 916, and ion implantation A hole confinement structure including an ion non-implanting conduction region 917 surrounded by the high resistance region 916 is provided. Here, the length of one side of the non-ion-implanted conduction region 917 is 10 μm. Thereafter, the resist is removed, the growth surface is cleaned, and the remaining non-doped Al is again formed._0.8Ga_0.2Crystal growth of the As / GaAs upper semiconductor distributed Bragg reflector 908 is performed. By using the manufacturing method as described above, the ion implantation depth can be reduced, so that the high resistance region can be easily provided with good control.
[0222]
Further, as another manufacturing method, after crystal growth of the element, deep ion implantation can be performed so as to reach the vicinity of the active layer with a high acceleration voltage.
[0223]
In the surface emitting laser element of the ninth embodiment, as shown in FIG. 18, in order to make contact with the n-side electrode and the p-GaAs resonator spacer / contact layer 906g for conducting with the p-side electrode. N-GaAs resonator spacer / contact layer 906b, and the surface of each contact layer is removed by etching as shown in FIG. 17, and the lengths of one side are 30 μm and 50 μm, respectively. A stepped square mesa is formed.
[0224]
Next, the non-doped AlAs selectively oxidized layer 904 is selectively oxidized to form a high-order transverse mode suppression structure including a selective oxidation region 915 and a non-oxidation region 914. Here, the area of the non-oxidized region 914 is formed relatively smaller than the area of the ion non-implanted conduction region 917. Specifically, the length of one side of the non-ion-implanted conduction region 917 is 10 μm, and the length of one side of the non-oxidized region 914 is 5 μm.
[0225]
Next, a p-side electrode 911 and an n-side electrode 912 were formed to obtain the surface emitting laser element of FIG.
[0226]
The intracavity contact type surface emitting laser element of FIG. 17 has a structure in which no current is injected through the distributed Bragg reflector in both the upper part and the lower part, and since no doping is performed, there is little light absorption. The oscillation threshold current was low and the slope efficiency was high. Non-doped Al_0.8Ga_0.2The non-oxidized region 914 provided in the As / GaAs upper semiconductor distributed Bragg reflector 908 does not affect the resistance. Therefore, the resistance was very low. Therefore, the element has a very low resistance.
[0227]
The surface-emitting laser element shown in FIG. 17 has a low element resistance as described above, can obtain a high output while maintaining a single fundamental transverse mode oscillation, and can operate at a higher speed. Further, since the transverse mode confinement is performed by the selective oxidation structure, it is possible to stably obtain a single fundamental transverse mode oscillation even when the driving state of the element is changed. Thus, a long wavelength band intracavity contact type surface emitting laser device with particularly excellent performance could be obtained.
[0228]
(Tenth embodiment)
FIG. 19 is a diagram showing a surface emitting laser element according to the tenth embodiment. The surface emitting laser element of FIG. 19 is a 1.3 μm band surface emitting laser element having a GaInNAs / GaAs multiple quantum well structure as an active layer. All of the intracavity contact type surface emitting laser elements described so far have the configuration in which the substrate side is n-conductive type with respect to the resonance region, but the element of the tenth embodiment is p-conductive on the substrate side. It becomes the composition used as a model. The structure will be described below.
[0229]
The device shown in FIG. 19 is a 36-period non-doped AlAs / GaAs lower semiconductor distributed Bragg reflector in which a non-doped GaAs buffer layer 1002 is grown on a semi-insulating GaAs substrate 1001 and then one AlAs / GaAs pair is formed. 1003, resonance region 1013, Al_0.8Ga_0.220 periods of non-doped Al with one As / GaAs pair_0.8Ga_0.2The As / GaAs upper semiconductor distributed Bragg reflector 1008 is formed by crystal growth.
[0230]
Here, the resonance region 1013 includes a GaInNAs / GaAs multiple quantum well structure 1007 and a GaAs resonator spacer layer 1006. In the GaAs resonator spacer layer 1006, an n-AlAs selectively oxidized layer 1004 is formed. Is provided. The n-AlAs selectively oxidized layer 1004 includes a selectively oxidized region 1015 that has been oxidized by selective oxidation and a non-oxidized region 1014 that has not been oxidized. In addition, in the GaAs resonator spacer layer 1006, an ion implantation high resistance region 1016 and an ion non-implant conduction region 1017 are provided.
[0231]
FIG. 20 is a diagram showing in detail the periphery of the resonance region 1013 of the surface emitting laser element of FIG. That is, FIG. 20 shows one period of the non-doped AlAs / GaAs lower semiconductor distributed Bragg reflector 1003 formed by the non-doped AlAs lower semiconductor distributed Bragg reflector low-refractive layer 1003a and the non-doped GaAs lower semiconductor distributed Bragg reflector high-refractive layer 1003b. Structure and non-doped Al_0.8Ga_0.2Non-doped Al by As upper semiconductor distributed Bragg reflector low refractive layer 1008a and non-doped GaAs upper semiconductor distributed Bragg reflector high refractive layer 1008b_0.8Ga_0.2The structure of one period of the As / GaAs upper semiconductor distributed Bragg reflector 1008 and the configuration of the resonance region 1013 provided therebetween are shown.
[0232]
Here, in the resonance region 1013, after crystal growth of the non-doped AlAs / GaAs lower semiconductor distributed Bragg reflector 1003, the non-doped GaAs resonator spacer layer 1006a, the p-GaAs contact layer / resonator spacer layer 1006b, and p-GaAs. Resonator spacer layer 1006c, non-doped GaAs resonator spacer layer 1006d, non-doped GaInNAs / GaAs multiple quantum well structure 1007, non-doped GaAs resonator spacer layer 1006e, n-GaAs resonator spacer layer 1006f, n-AlAs selectively oxidized layer 1004 The n-GaAs resonator spacer layer 1006g, the n-GaAs contact / resonator spacer layer 1006h, and the non-doped GaAs resonator spacer layer 1006i are formed by crystal growth.
[0233]
In the surface emitting laser element of FIG. 19, non-doped Al_0.8Ga_0.2After partial crystal growth of the As / GaAs upper semiconductor distributed Bragg reflector 1008, the growth is interrupted, a resist pattern is formed, hydrogen ion implantation is performed, and an ion implantation high resistance region 1016 and ion implantation are performed. A hole confinement structure including an ion non-implanting conduction region 1017 surrounded by the high resistance region 1016 is provided. Here, the length of one side of the non-ion-implanted conduction region 1017 is 10 μm. Thereafter, the resist is removed, the growth surface is cleaned, and the remaining non-doped Al is again formed._0.8Ga_0.2Crystal growth of the As / GaAs upper semiconductor distributed Bragg reflector 1008 is performed. By using the manufacturing method as described above, the ion implantation depth can be reduced, so that the high resistance region can be easily provided with good control.
[0234]
Further, as another manufacturing method, after crystal growth of the element, deep ion implantation can be performed so as to reach the vicinity of the active layer with a high acceleration voltage.
[0235]
Next, the n-AlAs selectively oxidized layer 1004 is selectively oxidized to form a high-order transverse mode suppression structure including a selective oxidation region 1015 and a non-oxidation region 1014. Here, the area of the non-oxidized region 1014 is formed relatively smaller than the area of the non-ion-implanted conduction region 1017. Specifically, the length of one side of the non-ion-implanted conduction region 1017 is 10 μm, and the length of one side of the non-oxidized region 1014 is 5 μm. Next, an n-side electrode 1011 and a p-side electrode 1012 were formed to obtain the surface emitting laser element of FIG.
[0236]
The intracavity contact type surface emitting laser device of FIG. 19 has a structure in which no current is injected through a distributed Bragg reflector in both the upper and lower portions, and no doping is performed. Therefore, since the light absorption is small, the oscillation threshold current is low and the slope efficiency is high.
[0237]
The surface-emitting laser element of FIG. 19 has a low element resistance as described above, can obtain a high output while maintaining single fundamental transverse mode oscillation, and can operate at a higher speed. Further, since the transverse mode confinement is performed by the selective oxidation structure, it is possible to stably obtain a single fundamental transverse mode oscillation even when the driving state of the element is changed. Thus, a long wavelength band intracavity contact type surface emitting laser device with particularly excellent performance could be obtained. As described above, it is also possible to configure the substrate side as a p-conductivity type and the surface side as an n-conductivity type.
[0238]
(Eleventh embodiment)
FIG. 21 is a diagram showing a surface emitting laser element according to an eleventh embodiment. The surface emitting laser element of FIG._0.15Ga_0.85This is a 0.85 μm band surface emitting laser device having an As multiple quantum well structure as an active layer. The element of the eleventh embodiment is similar to the element of the first embodiment in that n-Al_0.9Ga_0.1As / Al_0.15Ga_0.85The example about the structure which makes multiple the high order transverse mode suppression structure provided in As lower semiconductor distributed Bragg reflector is shown. Except for this point, the element layer configuration is the same as that of the first embodiment, and the detailed layer configuration is as shown in the first embodiment. Therefore, only the vicinity of the resonator region 1113 will be described in detail. To do.
[0239]
FIG. 22 is a diagram showing in detail the periphery of the resonance region in the surface emitting laser element of FIG. That is, FIG. 22 shows n-Al._0.9Ga_0.1As lower semiconductor distributed Bragg reflector low refractive layer 1103a and n-Al_0.15Ga_0.85N-Al with As lower semiconductor distributed Bragg reflector high refractive layer 1103b_0.9Ga_0.1As / Al_0.15Ga_0.85A structure of three periods of the As lower semiconductor distributed Bragg reflector 1103, a resonance region 1113 provided thereon, and p-Al_0.9Ga_0.1As upper semiconductor distributed Bragg reflector low refractive layer 1108a and p-Al_{0. 15}Ga_0.85P-Al with As upper semiconductor distributed Bragg reflector high refractive layer 1108b_0.9Ga_0.1As / Al_0.15Ga_0.85The structure of one period of the As upper semiconductor distributed Bragg reflector 1108 is shown.
[0240]
In the surface emitting laser element of FIG. 21, as shown in FIG. 22, the n-Al is sequentially formed from the resonance region 1113 side._0.9Ga_0.1In the As lower semiconductor distributed Bragg reflector low-refractive layer 1103a, three layers of n-AlAs selectively oxidized layers 1104 each having a thickness of 30 nm are provided. Each n-AlAs selectively oxidized layer 1104 is provided at a position that becomes a node of a standing wave of oscillation light.
[0241]
In the element shown in FIG. 21, after each layer is crystal-grown, a hole confinement structure including an ion-implanted high resistance region 1116 and an ion non-implanted conduction region 1117 is provided by hydrogen ion implantation as in the first embodiment. Thereafter, mesa formation is performed, and a high-order transverse mode suppression structure including a selective oxidation region 1115 and a non-oxidation (conduction) region 1114 is provided by selective oxidation.
[0242]
At this time, the area of the non-oxidized region 1114 that forms the higher-order transverse mode suppressing structure is formed to be relatively smaller than the area of the ion non-implanted (conductive) region 1117 that forms the hole confinement structure. Specifically, the length of one side of the non-ion-implanted region 1117 is 10 μm, and the length of one side of the non-oxidized region 1114 is 3 μm.
[0243]
Next, SiO₂The insulating film 1109, the insulating resin 1110, the p-side electrode 1111 and the n-side electrode 1112 were formed to obtain the surface emitting laser element of FIG.
[0244]
The surface emitting laser element of FIG._0.9Ga_0.1In the As / GaAs lower semiconductor distributed Bragg reflector, a plurality of higher-order lateral mode suppression structures (three layers in the example of FIG. 21) each including a non-oxidized region 1114 and a selective oxidized region 1115 are provided. The single fundamental transverse mode oscillation could be obtained up to higher output. In addition, the device resistance was low, and high-speed operation was possible.
[0245]
(Twelfth embodiment)
FIG. 23 shows a surface emitting laser element according to the twelfth embodiment. The surface emitting laser element shown in FIG._0.15Ga_0.85This is a 0.85 μm band surface emitting laser device having an As multiple quantum well structure as an active layer. The element of the twelfth embodiment is similar to the element of the third embodiment in that n-Al_0.9Ga_0.1As / Al_0.15Ga_0.85The As upper semiconductor distributed Bragg reflector has a structure in which a plurality of higher-order transverse mode suppression structures are provided, and corresponds to a structure in which the upper and lower conductivity types of the active layer are inverted with respect to the element of the eleventh embodiment. is doing. The layer structure of the element is the same as that of the third embodiment except for the number of higher-order transverse mode suppression structures, and the detailed layer structure is as shown in the third embodiment. Describe in detail only the neighborhood of
[0246]
FIG. 24 is a diagram showing in detail the periphery of the resonance region 1213 of the surface emitting laser element of FIG. 23 together with the standing wave of the oscillation light. That is, in FIG. 24, p-Al_0.9Ga_0.1As lower semiconductor distributed Bragg reflector low refractive layer 1203a and p-Al_0.15Ga_0.85P-Al with As lower semiconductor distributed Bragg reflector high refractive layer 1203b_0.9Ga_0.1As / Al_0.15Ga_0.85The structure of one period of the As lower semiconductor distributed Bragg reflector 1203, the resonance region 1213 provided thereon, and n-Al_0.9Ga_0.1As upper semiconductor distributed Bragg reflector low refractive layer 1208a and n-Al_0.15Ga_0.85N-Al with As upper semiconductor distributed Bragg reflector high refractive layer 1208b_0.9Ga_0.1As / Al_0.15Ga_0.85The structure of three periods of the As upper semiconductor distributed Bragg reflector 1208 is shown.
[0247]
In the surface emitting laser element of FIG. 23, as shown in FIG. 24, n-Al is sequentially formed from the resonance region 1213 side._0.9Ga_0.1In the As upper semiconductor distributed Bragg reflector low-refractive layer 1208a, three layers of n-AlAs selectively oxidized layers 1204 each having a thickness of 20 nm are provided. As can be seen from FIG. 24, each n-AlAs selectively oxidized layer 1204 is provided at a position that becomes a node of the standing wave of the oscillation light.
[0248]
In the element shown in FIG. 23, after crystal growth of each layer, a hole confinement structure including an ion-implanted high resistance region 1216 and an ion non-implanted conduction region 1217 is provided by hydrogen ion implantation as in the third embodiment. Thereafter, mesa formation is performed, and a high-order transverse mode suppression structure including a selective oxidation region 1215 and a non-oxidation region 1214 is provided by selective oxidation.
[0249]
At this time, the area of the non-oxidized region 1214 forming the higher-order transverse mode suppressing structure is formed to be relatively smaller than the area of the ion non-implanted region 1217 forming the hole confinement structure. Specifically, the length of one side of the non-ion-implanted region 1217 is 10 μm, and the length of one side of the non-oxidized region 1214 is 3 μm.
[0250]
Next, SiO₂The insulating film 1209, the insulating resin 1210, the n-side electrode 1211, and the p-side electrode 1212 were formed to obtain the surface emitting laser element of FIG.
[0251]
The surface emitting laser element of FIG._0.9Ga_0.1In the As / GaAs upper semiconductor distributed Bragg reflector, by providing a plurality of selective oxidation structures (three layers in the example of FIG. 23) composed of non-oxidized regions 1214, the transverse mode selection capability is further improved. A single fundamental transverse mode oscillation could be obtained up to a high output. In addition, the device resistance was low, and high-speed operation was possible.
[0252]
(Thirteenth embodiment)
FIG. 25 is a diagram showing a surface emitting laser element according to a thirteenth embodiment. The surface emitting laser element shown in FIG. 25 is a 1.3 μm band surface emitting laser element having a GaInNAs / GaAs multiple quantum well structure as an active layer. The element of the thirteenth embodiment is the same as the element of the eighth embodiment, but is non-doped Al._0.8Ga_0.2A plurality of higher-order transverse mode suppression structures provided in the As / GaAs upper semiconductor distributed Bragg reflector are provided. The layer structure of the element is the same as that of the eighth embodiment except for the number of higher-order transverse mode suppression structures, and the detailed layer structure is as shown in the eighth embodiment. Only the vicinity will be described in detail.
[0253]
FIG. 26 is a diagram showing in detail the periphery of the resonance region 1313 in the surface emitting laser element of FIG. 25 together with the standing wave of the oscillation light. That is, FIG. 26 shows a p-AlAs / GaAs lower semiconductor distribution Bragg including a resonance region 1313, an n-AlAs lower semiconductor distributed Bragg reflector low refractive layer 1303a, and an n-GaAs lower semiconductor distributed Bragg reflector high refractive layer 1303b. The structure for one period of the reflector 1303 and non-doped Al_0.8Ga_0.2Non-doped Al by As upper semiconductor distributed Bragg reflector low refractive layer 1308a and non-doped GaAs upper semiconductor distributed Bragg reflector high refractive layer 1308b_0.8Ga_0.2The structure of five periods of the As / GaAs upper semiconductor distributed Bragg reflector 1308 is shown.
[0254]
In the surface emitting laser element of FIG. 25, as shown in FIG. 26, the n-Al is sequentially formed from the resonance region 1313 side._0.8Ga_0.2In the As upper semiconductor distributed Bragg reflector low-refractive layer 1308a, a non-doped AlAs selectively oxidized layer 1304 having a thickness of 20 m and a total of four layers is provided. As can be seen from FIG. 26, each non-doped AlAs selectively oxidized layer 1304 is provided at a position that becomes a node of a standing wave of oscillation light.
[0255]
In the surface emitting laser element of FIG. 25, non-doped Al_0.8Ga_0.2After crystal growth of a part of the As / GaAs upper semiconductor distributed Bragg reflector 1308 is performed, the growth is temporarily stopped, a resist pattern is formed, hydrogen ion implantation is performed, an ion implantation high resistance region 1316, and ion implantation A hole confinement structure including an ion non-implanting conduction region 617 surrounded by the high resistance region 1316 is provided. Here, the length of one side of the non-ion-implanted conduction region 1317 is 10 μm. Thereafter, the resist is removed, the growth surface is cleaned, and the remaining non-doped Al is again formed._0.8Ga_0.2Crystal growth of the As / GaAs upper semiconductor distributed Bragg reflector 1308 is performed. By using the manufacturing method as described above, the ion implantation depth can be reduced, so that the high resistance region can be easily provided with good control.
[0256]
Further, as another manufacturing method, after crystal growth of the element, deep ion implantation can be performed so as to reach the vicinity of the active layer with a high acceleration voltage.
[0257]
Next, as shown in FIG. 25, a two-step square mesa structure is formed by a known photolithography technique and a known dry etching technique. Here, the etching is performed so that the surface of the contact layer 1306d is exposed.
[0258]
Next, a high-order transverse mode suppression structure including a selective oxidation region 1315 and a non-oxidation region 1314 is provided by selective oxidation of the AlAs selectively oxidized layer 1304. Here, the length of one side of the non-oxidized region 1314 is 5 μm, and is relatively smaller than the area of the non-injection region in the hole confinement structure.
[0259]
The surface emitting laser element of FIG. 25 is non-doped Al in comparison with the element of the eighth embodiment._0.8Ga_0.2The non-doped AlAs selectively oxidized layer 1304 in the As / GaAs upper semiconductor distributed Bragg reflector 1308 is made into a plurality (four layers in the example of FIG. 25), and a plurality of non-oxidized regions 1314 are provided. The single fundamental transverse mode oscillation was obtained up to higher output. Further, since the non-oxidized region 1314 having a small area is provided in a region other than the current path, the resistance is very low. In addition, the device resistance was low, and high-speed operation was possible.
[0260]
As described above, a long-wavelength surface emitting laser element having excellent performance can be obtained.
[0261]
(Fourteenth embodiment)
FIG. 27 is a diagram showing a surface emitting laser element according to the fourteenth embodiment. The surface emitting laser element of FIG. 27 is a 1.3 μm band intracavity contact type surface emitting laser element having a GaInNAs / GaAs multiple quantum well structure as an active layer, and is a high-order transverse mode provided in a lower semiconductor distributed Bragg reflector. It is the structure which makes the suppression structure more than one. The layer structure of the element is different from the 0.85 μm band intracavity contact type surface emitting laser element of the fourth embodiment in that the number of AlAs selectively oxidized layers is different from that of the semiconductor material constituting the element. The configuration of the element is the same as that of the fourth embodiment. A specific semiconductor material in the surface emitting laser element of the fourteenth embodiment is as shown in the explanation of the reference numerals in FIG.
[0262]
In the device of the fourteenth embodiment, n-Al_0.8Ga_0.2In the As / GaAs lower semiconductor distributed Bragg reflector 1403, 30 nm-thick n-AlAs selectively oxidized layers 1404 are respectively measured in order from the resonance region 1413 side at a position corresponding to the node of the standing wave of the oscillation light. Three layers are provided, whereby three higher-order transverse mode suppression structures are formed.
[0263]
In the surface emitting laser element of the fourteenth embodiment, non-doped Al_0.8Ga_0.2After partial crystal growth of the As / GaAs upper semiconductor distributed Bragg reflector 1408, the growth is interrupted, a resist pattern is formed, hydrogen ion implantation is performed, an ion implantation high resistance region 1416, and an ion implantation are performed. A hole confinement structure including an ion non-implanting conduction region 1417 surrounded by the high resistance region 1416 is provided. Here, the length of one side of the non-ion-implanted conduction region 1417 is 10 μm. Thereafter, the resist is removed, the growth surface is cleaned, and the remaining non-doped Al is again formed._0.8Ga_0.2Crystal growth of the As / GaAs upper semiconductor distributed Bragg reflector 1408 is performed. By using the manufacturing method as described above, the ion implantation depth can be reduced, so that the high resistance region can be easily provided with good control.
[0264]
As another manufacturing method, after crystal growth of the device, as in the fourth embodiment, deep ion implantation can be performed so as to reach the vicinity of the active layer with a high acceleration voltage.
[0265]
In the surface emitting laser element of FIG. 27, after forming a two-step square mesa structure, ion implantation high resistance region 1416 and ion non-resistance region 1416 surrounded by ion implantation high resistance region 1416 are formed by hydrogen ion implantation. A hole confinement structure including an injection region 1417 is provided. Here, the length of one side of the non-implanted region 1417 is 10 μm.
[0266]
Next, a selective oxidation region 1415 and a non-oxidation region 1414 are formed by selective oxidation of the AlAs selectively oxidized layer 1404. Here, the length of one side of the non-oxidized region 1414 is 5 μm, and is relatively smaller than the area of the non-injection region in the hole confinement structure. Here, the structure including the selective oxidation region 1415 and the non-oxidation region 1414 is provided as a high-order transverse mode suppression structure.
[0267]
In the intracavity contact type surface emitting laser element of FIG. 27, a plurality of high-order transverse mode suppression structures in the lower distributed Bragg reflector are provided (three in the example of FIG. 27), so that the transverse mode selection ability is further improved. It was improved and single fundamental transverse mode oscillation could be obtained up to higher output. In addition, since the non-oxidized region 1414 having a small area is provided in a region other than the current path, the resistance is very low. In addition, the device resistance was low, and high-speed operation was possible. As described above, a long-wavelength surface emitting laser element having excellent performance can be obtained.
[0268]
(15th Example)
FIG. 28 is a diagram showing a surface emitting laser element according to the fifteenth embodiment. The surface emitting laser element of FIG. 28 is a 1.3 μm band surface emitting laser element having a GaInNAs / GaAs multiple quantum well structure as an active layer. In addition, the element of the fifteenth embodiment has a structure in which the p-side electrode and the n-side electrode are provided on the substrate surface in the element of the fourteenth embodiment. Except for this point, the structure of the element is similar to that of the fourteenth embodiment. Further, specific semiconductor materials in the surface emitting laser element of the fifteenth embodiment are as shown in the explanation of the reference numerals in FIG.
[0269]
In the device of FIG. 28, non-doped Al_0.8Ga_0.2In the As / GaAs lower semiconductor distributed Bragg reflector 1503, 20 nm thick n-AlAs selectively oxidized layers 1504 are respectively measured in order from the resonance region 1513 side at a position corresponding to the standing wave node of the oscillation light. Three layers are provided, whereby three higher-order transverse mode suppression structures are formed.
[0270]
In the surface emitting laser element of FIG. 28, non-doped Al_0.8Ga_0.2After partial crystal growth of the As / GaAs upper semiconductor distributed Bragg reflector 1508, the growth is interrupted, a resist pattern is formed, hydrogen ions are implanted, an ion implantation high resistance region 1516, and an ion implantation A hole confinement structure including an ion non-implanting conduction region 1517 surrounded by the high resistance region 1516 is provided. Here, the length of one side of the non-ion-implanted conduction region 1517 is 10 μm. Thereafter, the resist is removed, the growth surface is cleaned, and the remaining non-doped Al is again formed._0.8Ga_0.2Crystal growth of the As / GaAs upper semiconductor distributed Bragg reflector 1508 is performed. By using the manufacturing method as described above, the ion implantation depth can be reduced, so that the high resistance region can be easily provided with good control.
[0271]
As another manufacturing method, after crystal growth of the device, as in the fourth embodiment, deep ion implantation can be performed so as to reach the vicinity of the active layer with a high acceleration voltage.
[0272]
In the surface emitting laser element of FIG. 28, after forming a two-step square mesa structure, ion implantation high resistance region 1516 and ion non-resistance region 1516 surrounded by ion implantation high resistance region 1516 are formed by hydrogen ion implantation. A hole confinement structure including an injection region 1517 is provided. Here, the length of one side of the non-implanted region 1517 is 10 μm.
[0273]
Next, a selective oxidation region 1515 and a non-oxidation region 1514 are formed by selective oxidation of the n-AlAs selectively oxidized layer 1504. Here, the length of one side of the non-oxidized region 1514 is 5 μm, and is relatively smaller than the area of the non-injection region in the hole confinement structure. Here, the structure including the selective oxidation region 1515 and the non-oxidation region 1514 is provided as a high-order transverse mode suppression structure.
[0274]
In the intracavity contact type surface emitting laser element of FIG. 28, a plurality of high-order transverse mode suppression structures in the lower distributed Bragg reflector are provided (three in the example of FIG. 28), so that the transverse mode selection ability is further improved. It was improved and single fundamental transverse mode oscillation could be obtained up to higher output. In addition, the device resistance was low, and high-speed operation was possible. As described above, a long-wavelength surface emitting laser element having excellent performance can be obtained.
[0275]
(Sixteenth embodiment)
FIG. 29 is a diagram showing a surface emitting laser array according to the sixteenth embodiment. 29 shows a top view of a monolithic laser array in which 4 × 4 surface emitting laser elements of the present invention are integrated two-dimensionally. In the example of FIG. 29, wirings are individually provided on the upper electrode in order to drive each element independently. In addition, the surface emitting laser array of FIG. 29 is manufactured by the same procedure and method as the above-described embodiments.
[0276]
Each of the individual elements constituting the surface emitting laser array of FIG. 29 has a high-order transverse mode suppression structure in the middle of the electron path or in a region avoiding the electron and hole paths, increasing the element resistance. Therefore, the oscillation in the high-order transverse mode is suppressed. In addition, the hole confinement structure having a large conduction region by hydrogen ion implantation provided in the p-type distributed Bragg reflector restricts the hole injection region to the mesa center without significantly increasing the element resistance. Accordingly, the resistance is low and the oscillation region can be widened. Therefore, it generated less heat and oscillated in a single fundamental transverse mode up to high output. As described above, a surface emitting laser array that operates at a high output in a single transverse mode was obtained.
[0277]
(Seventeenth embodiment)
30 and 31 are views showing a multiwavelength surface emitting laser array according to the seventeenth embodiment. FIG. 30 shows a multiwavelength surface emitting laser array composed of 2 × 3 1.55 μm band surface emitting laser elements having a GaInNAs / GaAs multiple quantum well structure as an active layer. FIG. It is a figure which shows the structure about two adjacent elements A and B located in the area | region R by a wavelength surface emitting laser array.
[0278]
The multiwavelength surface emitting laser array of the seventeenth embodiment has an intracavity contact structure in which an electrode for performing carrier injection is provided in a semiconductor layer inside a surface emitting laser element, as shown in FIG. Furthermore, a high-order transverse mode suppression structure for performing oscillation transverse mode control is provided in a region avoiding the hole passage and the electron passage.
[0279]
In addition, as shown in FIG. 31, the multi-wavelength surface emitting laser array of the seventeenth embodiment is provided with p-side electrodes 1711 for independently driving the individual surface emitting laser elements on the upper surface of the surface emitting laser element. It has been. An n-side common electrode 1712 is provided on the back surface of the substrate 1701.
[0280]
Further, the multi-wavelength surface emitting laser array of the seventeenth embodiment has a configuration in which the mesa diameters of the surface emitting laser elements in the array are different from each other, as will be described later. In FIG. 31, the size of the upper mesa gradually increases toward the direction of change of the upper mesa size shown in the figure. In addition, for example, referring to FIG. 31 showing two adjacent elements A and B, the element A is produced with a relatively large upper mesa size with respect to the element B.
[0281]
Next, the structure of the multiwavelength surface emitting laser array of the seventeenth embodiment will be described. Each surface emitting laser element of FIG. 31 has an n-GaAs buffer layer 1702 and an n-Al on an n-GaAs substrate 1701._0.8Ga_0.2As / GaAs lower semiconductor distributed Bragg reflector 1703, resonant region 1713, non-doped Al_0.8Ga_0.2The As / GaAs upper distributed Bragg reflector 1708 is formed by crystal growth.
[0282]
Where non-doped Al_0.8Ga_0.2In the As / GaAs upper distributed Bragg reflector 1708, a non-doped AlAs selectively oxidized layer 1704 is provided. Similarly to the sixth embodiment, the resonance region 1713 includes a GaAs resonator spacer layer 1706 and a GaInNAs / GaAs multiple quantum well structure 1707.
[0283]
In this surface emitting laser element, non-doped Al_0.8Ga_0.2After partial crystal growth of the As / GaAs upper semiconductor distributed Bragg reflector 1708, the growth is temporarily interrupted, a resist pattern is formed, hydrogen ion implantation is performed, an ion implantation high resistance region 1516, and an ion implantation height A hole confinement structure including an ion non-implanting conduction region 1717 surrounded by the resistance region 1516 is provided. Here, the length of one side of the non-ion-implanted conduction region 1717 is 10 μm. Thereafter, the resist is removed, the growth surface is cleaned, and the remaining non-doped Al is again formed._0.8Ga_0.2Crystal growth of the As / GaAs upper semiconductor distributed Bragg reflector 1708 is performed. By using the manufacturing method as described above, the ion implantation depth can be reduced, so that the high resistance region can be easily provided with good control.
[0284]
As another manufacturing method, after crystal growth of the element, ion implantation can be performed deeply so as to reach the vicinity of the active layer with a high acceleration voltage as in Example 4.
[0285]
Next, as in the above-described embodiments, a square two-stage mesa shape is formed by two etchings using a known photolithography technique and etching technique as shown in FIG. Here, when the upper mesa is formed, the mesa diameter is changed in the surface emitting laser array. In FIG. 31, as described above, the diameter of the upper mesa of the element A is made larger than the diameter of the upper mesa of the element B. Thereafter, the undoped AlAs selectively oxidized layer 1704 is oxidized by selective oxidation to form a selectively oxidized region 1715 and non-oxidized regions 1714a and 1714b.
[0286]
Here, the oxidation rate of the non-doped AlAs selectively oxidized layer 1704 is the same in the element A and the element B, but the diameter of the upper mesa of the element A is relatively larger than the diameter of the upper mesa of the element B. Thus, the area of the non-oxidized region 1714a is formed to be relatively larger than the area of the non-oxidized region 1714b. The areas of the non-oxidized regions 1714a and 1714b are both smaller than the area of the ion non-implanted conductive region 1717. Here, the selective oxidation structure including the selective oxidation region 1715 and the non-oxidation regions 1714a and 1714b is provided as a high-order transverse mode suppression structure.
[0287]
Further, in the multi-wavelength surface emitting laser array of FIG. 30, the diameters of the upper mesas of the surface emitting laser elements constituting the array are made different from each other in all the surface emitting laser elements, and the high-order transverse mode is suppressed. The area of the non-oxidized region of the structure is different for all surface emitting laser elements.
[0288]
Next, the surface emitting laser element SiO₂An insulating film 1709 is formed, and a p-side electrode 1711 is formed by vapor deposition and lift-off. Next, an n-side electrode 1712 is vapor-deposited on the back surface of the substrate, and ohmic conduction is obtained by annealing, so that the multi-wavelength surface emitting laser arrays of FIGS. 36 and 37 can be manufactured.
[0289]
In the surface emitting laser array of FIG. 30, the surface areas of the non-oxidized regions in the high-order transverse mode suppressing structure are different from each other in all the surface emitting laser elements in the array. ing. A surface emitting laser element with a smaller area of the non-oxidized region of the higher-order transverse mode suppression structure can oscillate at a shorter wavelength. The wavelength interval of each surface emitting laser element constituting the multi-wavelength surface emitting laser array of the seventeenth embodiment is 1 nm, and an oscillation wavelength from 1546 nm to 1553 nm can be obtained.
[0290]
31 has a structure in which no current is injected through the upper semiconductor distributed Bragg reflector, and the upper semiconductor distributed Bragg reflector is non-doped. Further, the surface emitting laser element of FIG. 31 has a low loss because a p-type distributed Bragg reflector having a large light absorption is not used. For this reason, the oscillation threshold current is low and the slope efficiency is high. Furthermore, a high output can be obtained.
[0291]
In addition, the high-order transverse mode suppression structure is non-doped Al._0.8Ga_0.2Since it is provided in the As / GaAs upper semiconductor distributed Bragg reflector 1908, the non-oxidized regions 1714a and 1714b do not contribute to the element resistance. Accordingly, the surface emitting laser element has a very low resistance and generates little heat. Therefore, the surface emitting laser element shown in FIG. 31 is capable of high output operation. Further, the surface emitting laser element of FIG. 31 has an ion non-implanting conduction region having the same area, and the distribution in the array such as the oscillation threshold current and the operating voltage of each surface emitting laser element is very small. A multi-wavelength surface emitting laser array having uniform characteristics can be obtained. In the multi-wavelength surface emitting laser array of the seventeenth embodiment, high output can be obtained by single fundamental transverse mode oscillation.
[0292]
In the above example, a multi-wavelength surface emitting laser array composed of 2 × 3 surface emitting laser elements has been described. However, the array form (number of elements, arrangement of elements) should be other than this. You can also.
[0293]
(Eighteenth embodiment)
FIG. 32 shows the electrophotographic system of the 18th embodiment. The electrophotographic system of FIG. 32 includes a photosensitive drum, an optical scanning system (scanning convergence optical system), a writing light source, and a synchronization control circuit (synchronization control unit). A surface emitting laser element or a surface emitting laser array is used.
[0294]
The electrophotographic system of FIG. 32 is controlled by a synchronous control circuit, and light from a writing light source (surface emitting laser element) is condensed on a photosensitive drum by a scanning converging optical system including a polygon mirror and a lens converging system. Form an image. Conventionally, the surface emitting laser element has been difficult to operate at high output due to the influence of heat generation, but the surface emitting laser element of the present invention can operate at a higher output than conventional elements, and is a writing light source for an electrophotographic system. Can be used as In addition, since the oscillation mode is also a single basic transverse mode, the far-field image is unimodal and the beam can be easily collected, so that high-definition image quality can be obtained.
[0295]
Further, a red surface emitting laser element using an AlGaInP-based material as an active layer material can oscillate at a shorter wavelength than an AlGaAs-based material with an oscillation wavelength of about 650 nm, and can increase the margin of optical design. Therefore, it is suitable as a writing light source for high-definition electrophotography. Such a red surface emitting laser element can be configured by using an AlGaInP-based material for the active layer and using an AlGaAs or AlGaInP-based material for the distributed Bragg reflector. In addition, since these materials can be crystal-grown with lattice matching with the GaAs substrate, an AlAs material or the like can be used as the selective oxidation layer. However, AlGaInP-based materials are very susceptible to temperature changes, and output saturation, oscillation stoppage, and the like are problematic due to temperature rise caused by element heat generation. However, the red surface emitting laser device according to the present invention has a high-order transverse mode suppression structure in which the area of the non-oxidized region formed by selective oxidation is small in the middle of the electron path or in a region avoiding the electron path and hole path. Therefore, high-order transverse mode oscillation can be suppressed without increasing the element resistance. In addition, holes are confined by a hole confinement structure having an ion non-implanting region with a large area provided in the middle of a hole passage such as a p-type distributed Bragg reflector. This does not increase the low resistance of the device.
[0296]
As described above, the element heat generation is reduced, and a high output operation is possible in the single fundamental transverse mode oscillation as compared with the conventional case. Thus, the surface emitting laser element or the surface emitting laser array of the present invention is suitable as a writing light source for an electrophotographic system.
[0297]
In addition, since the multi-beam writing system can be obtained by using the surface emitting laser array of the sixteenth embodiment, the writing speed and the like can be increased as compared with the conventional one. From the above, a high-speed and high-definition electrophotographic system can be obtained.
[0298]
(Nineteenth embodiment)
FIG. 33 shows the outline of the surface emitting laser module of the nineteenth embodiment. The laser array module of FIG. 33 is configured by mounting a one-dimensional monolithic surface emitting laser array, a microlens array, and a fiber array on a silicon substrate.
[0299]
Here, the surface emitting laser array is provided facing the fiber, and is coupled to a quartz single mode fiber mounted in a V-groove formed in the silicon substrate via a microlens array. The oscillation wavelength of the surface emitting laser array is 1.3 μm band, and high-speed transmission can be performed by using a quartz single mode fiber. Further, the surface emitting laser module of the nineteenth embodiment uses the surface emitting laser array according to the present invention, so that it stably oscillates in the fundamental transverse mode against changes in driving conditions such as environmental temperature. Further, a change in the coupling ratio with the fiber is small, and a highly reliable laser module can be obtained.
[0300]
(20th embodiment)
FIG. 34 is a diagram showing an optical interconnection system of the twentieth embodiment. In the interconnection system of FIG. 34, the device 1 and the device 2 are connected using an optical fiber array. The device 1 on the transmission side is provided with a one-dimensional laser array module using the surface emitting laser element or the surface emitting laser array according to the present invention, and a drive circuit thereof. The device 2 on the receiving side is provided with a photodiode array module and a signal detection circuit.
[0301]
Further, the optical interconnection system of the twentieth embodiment uses the surface emitting laser array according to the present invention, so that it stably oscillates in the fundamental transverse mode even when the driving conditions such as the environmental temperature change. In addition, there is little change in the coupling ratio with the fiber, and a highly reliable interconnection system can be configured. In the twentieth embodiment, the parallel optical interconnection system has been described as an example. However, a serial transmission system using a single element can also be configured. In addition to inter-device, it can also be applied to inter-board, inter-chip, and intra-chip interconnections.
[0302]
(Twenty-first embodiment)
FIG. 35 shows an optical communication system according to the twenty-first embodiment. The optical communication system of FIG. 35 is configured by configuring an optical LAN system using the surface emitting laser element or the surface emitting laser array element according to the present invention. That is, the surface emitting laser element or the surface emitting laser array of the present invention is used as a light transmission source between the server and the core switch, between the core switch and each switch, and between the switch and each terminal. It is used. Each device is coupled by a quartz single mode fiber or a multimode fiber. Examples of such a physical layer of the optical LAN include gigabit Ethernet such as 1000BASE-LX. In the optical LAN system shown in FIG. 35, the surface emitting laser element according to the present invention is used as the laser element of the light source, so that it stably oscillates in the fundamental transverse mode against changes in driving conditions such as environmental temperature. Therefore, a highly reliable interconnection system can be configured.
[0303]
(Twenty-second embodiment)
FIG. 36 shows a wavelength division multiplexing (WDM) communication system according to the twenty-second embodiment. The wavelength division multiplexing communication system of FIG. 36 includes a light source using a multiwavelength surface emitting laser array of the present invention, a WDM multiplexer, a quartz multimode fiber, a WDM demultiplexer, and a light receiver.
[0304]
Here, an arrayed wave guide grating (AWG) or the like can be used as the duplexer and the multiplexer. As the multiwavelength surface emitting laser array, a surface emitting laser array using GaInNAsSb as an active layer material as shown in the seventeenth embodiment with an oscillation wavelength of 1.55 μm band can be used. Here, the wavelength interval of each surface emitting laser element in the surface emitting laser array is 1 nm. In the wavelength division multiplexing communication system of FIG. 36, four surface emitting laser arrays having eight elements with different center wavelengths are used to form a 32-channel system. Signals transmitted from the surface emitting laser elements in the surface emitting laser array are multiplexed by a multiplexer, propagated through one multimode fiber, and sent again to a light receiver corresponding to the wavelength by a duplexer. Converted into an electrical signal.
[0305]
The multi-wavelength surface emitting laser array, which is the light source of the optical communication system of the twenty-second embodiment, has a low resistance of each surface emitting laser element as described above, and obtains a high output in basic single transverse mode oscillation. Can do. Therefore, high-speed modulation is possible, and variations in the characteristics of the surface emitting laser elements in the array such as the oscillation threshold current are very small. Therefore, no complicated driving circuit is required to drive the array. As a result, it is possible to configure a low-cost and highly reliable optical communication system.
[0306]
In the twenty-second embodiment, the wavelength multiplex communication system in the 1.55 μm band has been described as an example. However, the wavelength band may be other wavelength bands such as the 1.3 μm band. The material and composition of the elements constituting the multi-wavelength surface emitting laser array can be optimally selected according to the wavelength band. Also, the number of channels and the wavelength interval can be other combinations depending on the application. In addition to the quartz multimode fiber, a quartz single mode fiber, POF, or the like can be used as the optical fiber. Moreover, an optimal fiber can be used according to the wavelength band to be used.
[0307]
In each of the above embodiments, the MOCVD method has been described as an example of the crystal growth method, but other crystal growth methods such as a molecular beam crystal growth method (MBE method) are also available. Can also be used. In addition to the n-type substrate and the semi-insulating substrate, a p-type substrate may be used as the substrate. The oscillation wavelength may be other than the above-mentioned 670 nm band, 0.98 μm band, and 1.3 μm band, and may be a wavelength band other than the 1.5 μm band and the 0.85 μm band. Other than the above may be used depending on the oscillation wavelength. The element structure may be a structure other than that shown in each of the above-described embodiments, and the element shown in each of the embodiments may have another oscillation wavelength. Moreover, by selecting the material and configuration of the distributed Bragg reflector optimally according to the oscillation wavelength, an element corresponding to any oscillation wavelength can be formed with any structure.
[0308]
Also, materials other than those described above can be used for the material constituting the distributed Bragg reflector such as a dielectric. Also, the length and structure of the resonator can be other than those described above. In order to further reduce the resistance of the element, it is effective to provide a hetero spike buffer layer having a composition between them at the hetero interface such as Al (Ga) As / GaAs. A hetero spike buffer layer may also be provided at the interface of the layers. Examples of the hetero spike buffer layer include a single layer having a composition between two layers constituting a hetero interface, a combination of a plurality of layers having different compositions, and a composition whose composition is continuously changed.
[0309]
【The invention's effect】
As described above, according to the first to tenth aspects of the present invention, the active layer, the pair of distributed Bragg reflectors opposed to each other with the active layer interposed therebetween, and the first electrode reach the active layer. In a surface-emitting laser element comprising a hole path and an electron path that reaches the active layer from the second electrode,
In the middle of the hole passage, a hole confinement that defines a hole injection region into the active layer, which is configured by a high resistance region provided by ion implantation and a conduction region surrounded by the high resistance region In addition to the hole confinement structure, a structure is provided that includes a selectively oxidized region formed by selectively oxidizing a semiconductor layer containing Al as a constituent element and a non-oxidized region surrounded by the selectively oxidized region. A high-order transverse mode suppression structure is provided, and the non-oxidized region of the high-order transverse mode suppression structure has a smaller area than the conduction region of the hole confinement structure, so that the element resistance is low, and A surface emitting laser element capable of obtaining high output in one basic transverse mode and capable of high speed operation can be provided.
[0310]
That is, in the conventional oxide surface emitting laser element, single fundamental transverse mode control and current confinement are performed by the same oxide layer, and the oxide layer is a hole injection side with high carrier confinement efficiency. Is provided. This is because, of the two types of carriers, holes have a smaller mobility than electrons, and therefore do not easily diffuse after constriction, and a high constriction effect can be maintained. In addition, by making the diameter or length of one side of the non-oxidized region of the hole confinement layer as small as about 3 to 4 times the oscillation wavelength, high-order transverse mode oscillation is suppressed, and single fundamental transverse mode oscillation is achieved. Obtainable. However, due to the small hole mobility, the constriction of the hole confinement layer is likely to have a high resistance, and when the area of the non-oxidation (conduction) region is reduced to the extent that it becomes a single fundamental transverse mode, the device is very It was difficult to obtain high output and high speed operation.
[0311]
Similarly, the ion-implanted surface-emitting laser element has a structure in which a hole confinement structure with a high resistance region is provided in a p-conduction type distributed Bragg reflector for current confinement. Transverse mode control is performed by the lens effect. However, since it does not have a built-in optical confinement structure, the transverse mode is very unstable with respect to the operating state of the device, and it is difficult to obtain a high output in the single fundamental transverse mode.
[0312]
Therefore, in the surface-emitting laser device according to any one of claims 1 to 10, in order to prevent the increase in resistance as described above, a high-order transverse mode oscillation is suppressed separately from the hole confinement layer. A next transverse mode suppression structure is newly provided, and the area of the non-oxidized region in the higher order transverse mode suppression structure is made smaller than the area of the non-oxidized region in the hole confinement structure. As described above, by providing the hole confinement structure and the high-order transverse mode suppression layer, it is possible to design each structure independently and optimally.
[0313]
According to the configuration of claim 1 to claim 10, the high-order transverse mode suppression structure provided by selectively oxidizing the semiconductor layer containing Al in the composition forms a transverse mode light confinement structure in the surface emitting laser, An operation for stabilizing the oscillation state against a change in the driving state is provided. Further, by providing a small area of the non-oxidized region, it is possible to suppress high-order transverse mode oscillation and obtain single fundamental transverse mode oscillation.
[0314]
In addition, the hole confinement structure having a larger hole confinement region than the non-oxidation region in the high-order transverse mode suppression structure formed by ion implantation prevents carriers from diffusing to the side surface of the mesa and is high. Has the function of obtaining internal quantum efficiency. In addition, by adopting a configuration in which a high-order transverse mode suppression structure and a current confinement structure are separately provided, it is possible to provide a wide hole confinement region, to enlarge an oscillation region, and to reduce an increase in device resistance. I can do things. Further, by reducing the increase in element resistance, a high output operation is possible. As described above, according to the first to tenth aspects of the present invention, it is possible to obtain a surface emitting laser element having a low element resistance, a high output in a single fundamental transverse mode, and a high-speed operation.
[0315]
More specifically, in the invention according to claim 2, the transverse mode is suppressed in the surface emitting laser by the high-order transverse mode suppression structure provided by selectively oxidizing the semiconductor layer containing Al in the composition provided in the electron path. An optical confinement structure can be formed to stabilize the oscillation state against changes in the driving state. Further, by providing a small area of the non-oxidized region, it is possible to suppress high-order transverse mode oscillation and obtain single fundamental transverse mode oscillation.
[0316]
Furthermore, since the n-conductivity type semiconductor has an electrical resistance that is about an order of magnitude lower than that of the p-conductivity type semiconductor, the high-order transverse mode suppression structure according to claim 2 does not significantly increase the element resistance. Mode oscillation can be suppressed.
[0317]
In addition, the hole confinement structure having a larger hole confinement region than the non-oxidation region in the high-order transverse mode suppression structure formed by ion implantation prevents carriers from diffusing to the side surface of the mesa and is high. Internal quantum efficiency can be obtained. In addition, by adopting a configuration in which a high-order transverse mode suppression structure and a current confinement structure are separately provided, it is possible to provide a wide hole confinement region, to enlarge an oscillation region, and to reduce an increase in device resistance. I can do things. Further, by reducing the increase in element resistance, a high output operation can be made possible. As described above, according to the second aspect of the present invention, it is possible to obtain a surface emitting laser element having low element resistance, high output in a single fundamental transverse mode, and capable of high speed operation.
[0318]
According to a third aspect of the present invention, there is provided a high-order transverse mode suppression structure provided by selectively oxidizing a semiconductor layer containing Al in the composition provided avoiding an electron passage and a hole passage. Thus, the oscillation state can be stabilized against changes in the driving state. Further, by providing a small area of the non-oxidized region, it is possible to suppress high-order transverse mode oscillation and obtain single fundamental transverse mode oscillation.
[0319]
Furthermore, since the high-order transverse mode suppressing structure according to claim 3 is provided so as to avoid the electron passage and the hole passage, there is no influence on the element resistance. Therefore, the high-order transverse mode suppressing structure is not increased without increasing the element resistance. Mode oscillation can be suppressed.
[0320]
In addition, the hole confinement structure having a larger hole confinement region than the non-oxidation region in the high-order transverse mode suppression structure formed by ion implantation prevents carriers from diffusing to the side surface of the mesa and is high. Internal quantum efficiency can be obtained. In addition, by adopting a configuration in which a high-order transverse mode suppression structure and a current confinement structure are separately provided, it is possible to provide a wide hole confinement region, to enlarge an oscillation region, and to reduce an increase in device resistance. I can do things. Further, by reducing the increase in element resistance, a high output operation can be made possible. As described above, according to the third aspect of the present invention, it is possible to obtain a surface emitting laser element having low element resistance, high output in a single fundamental transverse mode, and capable of high speed operation.
[0321]
According to a fourth aspect of the present invention, in the surface emitting laser element according to any one of the first to third aspects, a distributed Bragg reflector made of a semiconductor material is used. By configuring an element using a Bragg reflector, each layer constituting the element can be provided by a single crystal growth, and high film thickness accuracy such as a resonance region and a distributed Bragg reflector is required. Each part can be formed with good controllability by the same apparatus. In addition, since an element can be manufactured using a semiconductor process technology with high controllability, a highly reliable element with little variation in characteristics can be obtained.
[0322]
According to a fifth aspect of the present invention, in the surface emitting laser element according to any one of the first to third aspects, the distributed Bragg reflector is made of a semiconductor material and a dielectric material. The dielectric material has less light absorption than the semiconductor material, and a high reflectance can be obtained with a small number of stacked layers. Absorption loss causes problems such as an increase in the oscillation threshold current of the element, slope efficiency, and reduction in output. In particular, semiconductor materials have the property that free carrier absorption and valence band absorption become more prominent and light absorption loss increases as the doping is increased. Further, light absorption becomes more conspicuous as light of a long wave. Therefore, there is a problem that it is difficult to obtain an element having a long wavelength band with excellent characteristics. On the other hand, a distributed Bragg reflector made of a dielectric material can reduce the absorption loss of oscillation light, and an element having excellent characteristics as described above can be obtained. Therefore, in particular, the surface emitting laser element according to claims 1 to 3 having excellent characteristics in the long wavelength band can be obtained. The surface-emitting laser device according to claims 1 to 3 has a small resistance, can perform fundamental single transverse mode oscillation up to a high output, and can perform high-speed modulation because of its low resistance. According to the configuration of the fifth aspect, it is possible to obtain a long-wavelength surface emitting laser element particularly suitable for optical fiber communication.
[0323]
Here, as a distributed Bragg reflector made of a dielectric material and a semiconductor material, when the low refractive index layer and the high refractive index layer are all dielectric materials, or a combination made of a dielectric material and a semiconductor material, etc. Is included. Further, the combination of a pair of distributed Bragg reflectors facing each other with the active layer interposed therebetween includes a case where at least one of them is made of only a semiconductor material.
[0324]
The surface emitting laser element according to claim 6 is the surface emitting laser element according to any one of claims 1 to 5, wherein at least one of the pair of distributed Bragg reflectors is an n-conductivity type semiconductor. It is a Bragg reflector, and further comprises a tunnel junction between the n-conductivity type semiconductor Bragg reflector and the active layer. As described above, the semiconductor Bragg reflector tends to have a large absorption loss due to doping, and this is particularly noticeable in the p-conductivity type semiconductor. Further, there is a problem that the resistance of the device is increased when the doping is low. Therefore, when a p-conductivity type semiconductor Bragg reflector is used, it is difficult to obtain an element having both excellent optical characteristics (low absorption) and electrical characteristics. However, in the tunnel junction, holes can be generated and injected into the active region by a reverse-biased heavily doped thin film pn junction by interband tunneling, and a p-conductivity type semiconductor Bragg reflector is not used. In addition, electrons and holes can be injected into the active region.
[0325]
Therefore, it is possible to reduce the absorption loss due to the semiconductor Bragg reflector. By using the structure of claim 6, the surface of claim 1 to claim 3, wherein the oscillation threshold current is low, the slope efficiency and the output are large. A light emitting laser element can be obtained. The surface-emitting laser element according to claims 1 to 3 has a small resistance and can perform fundamental single transverse mode oscillation up to a high output. Further, since the resistance is low, high-speed modulation is possible. Furthermore, the structure of claim 6 can obtain a surface emitting laser element having excellent characteristics in a long wavelength band where light absorption by a semiconductor is remarkable. Therefore, it is possible to obtain a surface emitting laser element particularly suitable for communication use. That is, according to the invention of claim 6, a surface emitting laser element having low element resistance, low absorption, high efficiency, high output operation, and capable of single fundamental transverse mode oscillation up to high output is obtained. Can do.
[0326]
According to a seventh aspect of the present invention, in the surface emitting laser element according to any one of the first to fifth aspects, at least one of the pair of distributed Bragg reflectors is non-doped. A semiconductor Bragg reflector, or a Bragg reflector including a region made up of a part of a non-doped semiconductor Bragg reflector, and further comprising the non-doped semiconductor Bragg reflector or a region made up of a non-doped semiconductor Bragg reflector and an active layer. The semiconductor layer is provided with an electrode for injecting carriers.
[0327]
As described above, the semiconductor Bragg reflector has a light absorption that increases as the doping is increased. Therefore, it is difficult to obtain an element excellent in both optical characteristics (low absorption) and electrical characteristics in a surface emitting laser element using a p-conductivity type semiconductor distributed Bragg reflector. However, in an intracavity contact type surface emitting laser element in which an electrode for performing carrier injection is provided in a semiconductor layer inside the element, it is possible to use a semiconductor distributed Bragg reflector in which part or all of it is non-doped. . Therefore, light absorption by the distributed Bragg reflector in the non-doped region can be reduced.
[0328]
Even in the case of an n-type semiconductor, although its degree is small, free carrier absorption increases due to high doping concentration, and light absorption becomes remarkable. Therefore, by making a part or all of the distributed Bragg reflector non-doped regardless of the conductivity type, the absorption loss of the oscillating light is reduced, thereby lowering the oscillation threshold current, increasing the slope efficiency and the output. The element according to claims 1 to 5 can be obtained. The surface-emitting laser elements according to claims 1 to 5 have a low resistance and can perform fundamental single transverse mode oscillation up to a high output. Moreover, since the resistance is low, high-speed modulation is possible. Furthermore, in the structure of claim 7, it is possible to obtain a surface emitting laser element having excellent characteristics in a long wavelength band where light absorption by the semiconductor is remarkable. Therefore, it is possible to obtain a surface emitting laser element particularly suitable for communication use. That is, according to the invention of claim 7, there is provided a surface emitting laser element having low element resistance, low absorption, high efficiency, high output operation, and capable of single fundamental transverse mode oscillation up to high output. be able to.
[0329]
In the surface emitting laser element according to the eighth aspect, a plurality of higher-order transverse mode suppression structures provided in the middle of the electron path or in a region avoiding the electron path and the hole path are used.
[0330]
By using a plurality of higher-order transverse mode suppression structures, a higher-order transverse mode suppression effect can be obtained more greatly. In the conventional element, when a plurality of selective oxidation structures having a small area of the non-oxidized region are provided, the increase in resistance becomes very significant. However, in the present invention, the high-order transverse mode suppression structure has an electric resistance. Since it is provided in the middle of a small electron path or in a region avoiding the electron path and hole path, there is little increase in resistance when there are a plurality of electron paths or in the latter case. As described above, there is an effect of improving the selectivity of the single fundamental transverse mode without significantly increasing the resistance. That is, according to the eighth aspect of the invention, it is possible to obtain a surface emitting laser element having low element resistance, capable of high output operation, and capable of single fundamental transverse mode oscillation up to higher output.
[0331]
According to a ninth aspect of the present invention, in the surface emitting laser element according to any one of the first to eighth aspects, at least one of Al, Ga, and In is used as the group III element constituting the active layer. And the group V element constituting the active layer includes at least one of As and P, and the oscillation wavelength is shorter than 1.1 μm.
[0332]
In a surface emitting laser element having an oscillation wavelength shorter than 1.1 μm, in order to perform single fundamental transverse mode control, the length or diameter of one side of the non-oxidized region needs to be about 5 μm or less. The increase is particularly noticeable. However, according to the ninth aspect, the element resistance can be reduced very effectively.
[0333]
This can provide a great effect particularly in a surface emitting laser in the visible band. For example, when an AlGaInP-based material is used as an active layer of a surface emitting laser element, a red surface emitting laser element having an oscillation wavelength in the 660 nm band can be obtained. In order to obtain the transverse mode oscillation, the length or diameter of one side of a very fine non-oxidized region of 3 μm or less is required, and the increase in resistance due to constriction becomes very significant. However, in the element of the present invention, the high-order transverse mode suppression structure that requires a small non-oxidized area is in the middle of an electron path that is difficult to increase in resistance (in an n-type semiconductor) or an electron path that does not contribute to resistance. In addition, since it is provided in a region avoiding the hole passage, single basic transverse mode control can be performed without increasing the resistance of the element.
[0334]
As described above, according to the ninth aspect of the present invention, in the surface emitting laser element whose oscillation wavelength is shorter than 1.1 μm, the element resistance can be reduced and the high output operation in the single fundamental transverse mode oscillation can be achieved.
[0335]
According to a tenth aspect of the present invention, in the surface emitting laser element according to any one of the first to eighth aspects, at least one of Ga and In is used as a group III element constituting the active layer. In addition, at least one of As, P, N, and Sb is included as a group V element constituting the active layer, and the oscillation wavelength is longer than 1.1 μm. A surface emitting laser element having an oscillation wavelength longer than 1.1 μm is very important as a quartz fiber communication light source. In particular, the 1.3 μm band is a zero dispersion band of quartz fiber, which enables long distance and high speed communication. The 1.5 μm band is an important wavelength band as a wavelength multiplexing communication band.
[0336]
Since the element of the present invention has a low element resistance, high-speed modulation is possible, and it is very suitable as such a light source. In addition, since high output is obtained in single fundamental transverse mode oscillation, long-distance communication is possible particularly in the 1.3 μm band, and a surface-emitting laser element suitable for an optical communication light source can be obtained as described above. .
[0337]
Thus, according to the invention of claim 10, a surface emitting laser element having an oscillation wavelength of 1.1 μm to 1.6 μm can be obtained on a GaAs substrate. On the GaAs substrate, it is possible to use a distributed Bragg reflector made of an AlGaAs mixed crystal having excellent characteristics, and an element having excellent characteristics can be obtained. Further, among these materials, GaInNAs material obtained by adding a small amount of nitrogen of several percent or less to GaInAs has a large conduction band discontinuity with respect to a barrier layer such as GaAs, and the same wavelength band element on a conventional InP substrate. Compared with better temperature characteristics. Furthermore, according to the first to eighth aspects of the invention, the element resistance is low and single transverse mode oscillation can be obtained up to a high output, so that the coupling efficiency with respect to an optical fiber or the like is particularly high. From the above, a surface emitting laser element suitable for optical fiber communication can be obtained.
[0338]
According to the invention described in claims 11 to 13, a surface-emitting laser array comprising the surface-emitting laser element according to any one of claims 1 to 10. Therefore, it is possible to provide a surface emitting laser array having low element resistance, capable of high output operation, and capable of single fundamental transverse mode oscillation up to high output. That is, in the surface emitting laser array according to the eleventh aspect, since the monolithic laser array is constituted by the surface emitting laser elements according to the first to tenth aspects, the element transverse resistance is low and the fundamental transverse mode oscillation is possible up to a high output. A surface emitting laser array can be obtained.
[0339]
Therefore, the surface emitting laser array of claims 11 to 13 is suitable as a light source for a multi-beam writing system of an electrophotographic system or an optical communication system.
[0340]
Particularly, in the invention of claim 12, in the surface emitting laser array according to claim 11, two or more kinds of surface emitting laser elements having different oscillation wavelengths due to different areas of the non-oxidized regions of the high-order transverse mode suppressing structure are used. A multi-wavelength surface emitting laser array is configured.
[0341]
In the multiwavelength surface emitting laser array according to claim 12, the oscillation wavelength in the array plane is changed by changing the area of the non-oxidized region of the high-order transverse mode suppression structure in each surface emitting laser element in the array. Yes. At this time, the surface emitting laser element of the present invention has a structure in which a hole confinement structure and a high-order transverse mode suppression structure are separately provided, and the high-order transverse mode suppression structure is not easily increased in resistance. In the semiconductor layer, or in a region avoiding an electron path and a hole path not related to electrical resistance. For this reason, the increase in resistance due to the small area of the non-oxidized region in the high-order transverse mode suppressing structure is small as compared with the element of the conventional structure, or not in the latter case at all.
[0342]
As described above, in the invention of claim 12, since the influence of heat generation due to the increase in resistance can be suppressed to a low level, the fundamental transverse mode oscillation is achieved for an element having a small area of the non-oxidized region of the high-order transverse mode suppressing structure. In addition, high output can be obtained, and variation in light output between elements can be reduced. Further, by making the hole confinement area in the separately provided hole confinement structure the same, variations in characteristics such as the oscillation threshold current and the operating voltage can be extremely reduced. As described above, it is possible to obtain a multi-wavelength surface emitting laser array with small variation in characteristics and capable of high output operation.
[0343]
Furthermore, since the influence of element heat generation (high resistance) can be reduced, it becomes possible to manufacture an element having a minute non-oxidized region, which has conventionally been difficult to obtain sufficient characteristics, and has a shorter oscillation wavelength. It becomes possible to create an element. As a result, it is possible to obtain a multi-wavelength surface emitting laser array having a wider band than conventional ones.
[0344]
According to a thirteenth aspect of the present invention, in the surface emitting laser array according to the twelfth aspect, each of the surface emitting laser elements constituting the surface emitting laser array includes a plurality of higher-order transverse mode suppression structures of two or more layers. It has become the composition.
[0345]
The change in the oscillation wavelength (resonance wavelength) by making the area of the non-oxidized region fine in the high-order transverse mode suppression structure is because the spread of the transverse mode changes depending on the selective oxidation structure (high-order transverse mode suppression structure). By reducing the spread of the transverse mode, a larger wavelength change effect can be obtained. According to the thirteenth aspect of the present invention, the confinement effect with respect to the fundamental transverse mode is increased by forming the transverse mode suppressing structure in multiple layers, and a multi-wavelength surface emitting laser array having a wider band than the conventional one can be obtained.
[0346]
In the invention of claim 13, as in the operation and effect of claim 12, the element resistance is low, a high output operation is possible, and the characteristic variation among the surface emitting laser elements constituting the array is small. A multi-wavelength surface emitting laser array can be obtained.
[0347]
According to the invention described in claim 14, a surface emitting laser module using the surface emitting laser element according to any one of claims 1 to 10 or the surface emitting laser array according to claim 11. Is configured. In the surface emitting laser element and the surface emitting laser array according to the present invention, oscillation is obtained up to a high output in the fundamental transverse mode, so that the coupling with the optical fiber is high and the oscillation of the higher order transverse mode is suppressed. Therefore, even when the operating state of the element such as the output changes, the coupling rate changes and the optical input to the fiber hardly changes. In addition, since the resistance is low, high speed operation is possible. Therefore, a highly reliable surface emitting laser module can be obtained.
[0348]
According to the invention described in claim 15, the surface-emitting laser element according to any one of claims 1 to 10 or the surface-emitting laser array according to claim 11 is used as a writing light source for electrons. It constitutes a photographic system.
[0349]
Conventional surface-emitting laser elements have a small output and are difficult to use as a writing light source for an electrophotographic system, but the surface-emitting laser elements and surface-emitting laser arrays of the present invention can oscillate to a high output in the fundamental transverse mode. It is done. Therefore, it can be used as a writing light source for an electrophotographic system. In addition, when a surface emitting laser element is used as a writing light source of an electrophotographic system, the beam is easily formed because the emitted beam is circular. Further, since the position accuracy between the arrays is high, a plurality of beams can be easily condensed with good reproducibility using the same lens. Therefore, the optical system is simple, and a high-definition system can be obtained at low cost. Further, since the surface emitting laser element of the present invention has a large output, high speed writing is possible particularly when an array is used. As described above, a low-cost, high-definition electrophotographic system can be obtained.
[0350]
According to the invention described in claim 16, the surface emitting laser element according to any one of claims 1 to 10 or the surface emitting laser array according to claim 11 is used as a light source. Configure the connection system.
[0351]
In the surface emitting laser element and the surface emitting laser array according to the present invention, the oscillation can be obtained up to a high output in the fundamental transverse mode, so that the coupling with the optical fiber is high. Further, since higher-order transverse mode oscillation is suppressed, even when the driving state of an element such as an output changes, it is very rare that the coupling rate changes and the optical input to the fiber changes. In addition, since the resistance is low, high speed operation is possible. Therefore, a highly reliable optical interconnection system can be obtained.
[0352]
According to the invention described in claim 17, optical communication is performed using the surface emitting laser element according to any one of claims 1 to 10 or the surface emitting laser array according to claim 11 as a light source. The system is configured.
[0353]
In the surface emitting laser element and the surface emitting laser array according to the present invention, oscillation is obtained up to a high output in the fundamental transverse mode, so that the coupling with the optical fiber is high. Further, since higher-order transverse mode oscillation is suppressed, even when the driving state of an element such as an output changes, it is very rare that the coupling rate changes and the optical input to the fiber changes. In addition, since the resistance is low, high speed operation is possible. In addition, since high output is obtained compared to the conventional case, long-distance communication is possible. Therefore, a highly reliable optical communication system can be obtained.
[0354]
According to the invention described in claim 18, an optical communication system is configured using the surface emitting laser array described in claim 12 or claim 13 as a light source.
[0355]
In the optical communication system according to claim 18, the multi-wavelength surface emitting laser array according to claim 12 or claim 13 is used as a communication light source, and the multi-wavelength surface emitting laser array according to claim 12 or claim 13 is used. The feature is that there is little variation in the characteristics of the surface emitting laser elements in the array and a high output can be obtained. Therefore, since the multi-wavelength surface emitting laser array according to claim 12 or 13 has the characteristics of the surface emitting laser elements in the array, the operation reliability is high and the drive circuit is simple. Cost can be lowered. In addition, since the element resistance is lower than that of the conventional element, high-speed modulation is facilitated. The surface-emitting laser array according to claim 12 or claim 13 is a multi-wavelength array in which the wavelengths of the individual surface-emitting laser elements are different, and thus is particularly suitable as a light source for a wavelength division multiplexing communication system. In wavelength division multiplex communication, high-speed and large-capacity communication can be performed by transmitting a plurality of signal lights having different wavelengths through a single fiber.
[0356]
As described above, the optical communication system configured by the multi-wavelength surface emitting laser array of the present invention has high reliability and can perform high-speed communication.
[0357]
Further, in the manufacturing method according to claim 19, as a manufacturing method of the multiwavelength surface emitting laser array according to claim 12 or 13, the diameter of the mesa portion including the high-order transverse mode suppression l structure is set in the array. The manufacturing method is changed.
[0358]
Since the oxidation rate of the high-order transverse mode suppression structure is constant in the plane, the diameter of the non-oxidized region remaining in the center of the mesa can be changed by changing the diameter of the mesa in this way. In addition, according to the manufacturing method of the nineteenth aspect, it is possible to fabricate a surface emitting laser element having a different area of the non-oxidized region at a time by one oxidation step, and at the same cost as the conventional one, The multi-wavelength surface emitting laser array of the invention can be easily manufactured.
[Brief description of the drawings]
FIG. 1 is a diagram showing a surface emitting laser element according to a first embodiment.
2 is a diagram illustrating in detail a resonance region (resonator region) of the surface emitting laser element of FIG. 1 together with a standing wave of oscillation light. FIG.
FIG. 3 is a diagram showing a surface emitting laser element according to a second embodiment.
4 is a diagram showing in detail the periphery of a resonance region of the surface emitting laser element of FIG. 3 together with a standing wave of oscillation light.
FIG. 5 is a diagram showing a surface emitting laser element according to a third embodiment.
6 is a diagram showing in detail the periphery of the resonance region of the surface emitting laser element of FIG.
FIG. 7 is a diagram showing a surface emitting laser element according to a fourth embodiment.
8 is a diagram showing in detail the periphery of the resonance region of the intracavity contact surface emitting laser element of FIG.
FIG. 9 is a diagram showing a surface emitting laser element according to a fifth embodiment.
10 is a diagram showing in detail the periphery of a resonance region in the intracavity contact type surface emitting laser element of FIG. 9. FIG.
FIG. 11 is a diagram showing a surface emitting laser element according to a sixth embodiment.
12 is a diagram showing in detail the periphery of a resonance region in the surface emitting laser element of FIG. 11. FIG.
FIG. 13 is a diagram showing a surface emitting laser element according to a seventh embodiment.
14 is a diagram showing in detail the periphery of a resonance region in the surface emitting laser element of FIG.
FIG. 15 is a diagram showing a surface emitting laser element according to an eighth embodiment.
16 is a diagram showing in detail a resonance region of the surface emitting laser element of FIG.
FIG. 17 is a diagram showing a surface emitting laser element according to a ninth embodiment.
18 is a diagram showing in detail the periphery of a resonance region in the surface emitting laser element of FIG.
FIG. 19 is a diagram showing a surface emitting laser element according to a tenth example.
20 is a diagram showing in detail the periphery of the resonance region of the surface emitting laser element of FIG.
FIG. 21 is a diagram showing a surface emitting laser element according to an eleventh embodiment.
22 is a diagram showing in detail the periphery of a resonance region in the surface emitting laser element of FIG. 21. FIG.
FIG. 23 is a diagram showing a surface emitting laser element according to a twelfth embodiment.
24 is a diagram showing in detail the periphery of the resonance region of the surface emitting laser element of FIG. 23 together with the standing wave of the oscillation light.
FIG. 25 is a diagram showing a surface emitting laser element according to a thirteenth embodiment.
26 is a diagram showing in detail the periphery of the resonance region in the surface-emitting laser element of FIG. 25 together with the standing wave of the oscillation light.
FIG. 27 is a diagram showing a surface emitting laser element according to a fourteenth example.
FIG. 28 is a diagram showing a surface emitting laser element according to a fifteenth embodiment.
FIG. 29 is a diagram showing a surface emitting laser array according to a sixteenth embodiment.
FIG. 30 is a diagram showing a multiwavelength surface emitting laser array according to a seventeenth embodiment.
FIG. 31 is a diagram showing a multiwavelength surface emitting laser array according to a seventeenth embodiment.
FIG. 32 is a diagram showing an electrophotographic system according to an eighteenth embodiment.
FIG. 33 is a diagram showing an outline of a surface emitting laser module according to a nineteenth embodiment.
FIG. 34 is a diagram showing an optical interconnection system of a twentieth embodiment.
FIG. 35 is a diagram illustrating an optical communication system according to a twenty-first embodiment.
FIG. 36 is a diagram illustrating a wavelength division multiplexing (WDM) communication system according to a twenty-second embodiment;
[Explanation of symbols]
101 n-GaAs substrate
102 n-GaAs buffer layer
103 n-Al_0.9Ga_0.1As / Al_0.15Ga_0.85As lower distribution Bragg reflector
103a n-Al_0.9Ga_0.1As lower distributed Bragg reflector low refractive index layer
103b n-Al_0.15Ga_0.85As lower distribution Bragg reflector high refractive index layer
104 n-AlAs selective oxidation layer
105 Non-doped Al_0.15Ga_0.85As resonator spacer layer
106 Non-doped GaAs / Al_0.15Ga_0.85As multiple quantum well active layer
107 Non-doped Al_0.15Ga_0.85As resonator spacer layer
108 p-Al_0.9Ga_0.1As / Al_0.15Ga_0.85As upper distributed Bragg reflector
108a p-Al_0.9Ga_0.1As upper distributed Bragg reflector low refractive index layer
108b p-Al_0.15Ga_0.85As upper distributed Bragg reflector high refractive index layer
113 Resonance region
114 Non-oxidized region
115 Selective oxidation region
116 Ion implantation high resistance region
117 Non-implanted conduction region
109 SiO₂Insulation layer
110 Insulating resin
111 p-side electrode
112 n-side electrode
201 n-GaAs substrate
202 n-GaAs buffer layer
203 n-Al_0.9Ga_0.1As / GaAs bottom distributed Bragg reflector
203a n-Al_0.9Ga_0.1As lower distributed Bragg reflector low refractive index layer
203b n-GaAs bottom distributed Bragg reflector high refractive index layer
204 n-AlAs selective oxidation layer
205 Non-doped GaAs resonator spacer layer
206 Non-doped GaInNAs / GaAs multiple quantum well active layer
207 Non-doped GaAs resonator spacer layer
208 p-Al_0.9Ga_0.1As / GaAs top distributed Bragg reflector
208a p-Al_0.9Ga_0.1As upper distributed Bragg reflector low refractive index layer
208b p-GaAs top distributed Bragg reflector high refractive index layer
209 SiO₂Insulation layer
210 Insulating resin
211 p-side electrode
212 n-side electrode
213 Resonance region
214 Non-selective oxidation region
215 Selective oxidation region
216 Ion implantation high resistance region
217 Ion non-implanted conduction region
218 Tunnel junction
219 n-Al_0.9Ga_0.1As / GaAs top distributed Bragg reflector
219a n-Al_0.9Ga_0.1As upper distributed Bragg reflector low refractive index layer
219b n-GaAs top distributed Bragg reflector high refractive index layer
301 p-GaAs substrate
302 p-GaAs buffer layer
303 p-Al_0.9Ga_0.1As / Al_0.15Ga_0.85As lower distribution Bragg reflector
303a p-Al_0.9Ga_0.1As lower distributed Bragg reflector low refractive index layer
303b p-Al_0.15Ga_0.85As lower distribution Bragg reflector high refractive index layer
304 n-AlAs selective oxidation layer
305 Non-doped Al_0.15Ga_0.85As resonator spacer layer
306 Non-doped GaAs / Al_0.15Ga_0.85As multiple quantum well active layer
307 Non-doped Al_0.15Ga_0.85As resonator spacer layer
308 n-Al_0.9Ga_0.1As / Al_0.15Ga_0.85As upper distributed Bragg reflector
308a n-Al_0.9Ga_0.1As upper distributed Bragg reflector low refractive index layer
308b n-Al_0.15Ga_0.85As upper distributed Bragg reflector high refractive index layer
309 SiO₂Insulation layer
310 Insulating resin
311 n-side electrode
312 p-side electrode
313 Resonance region
314 Non-oxidized region
315 selective oxidation region
316 Ion implantation high resistance region
317 Ion non-implanted conduction region
401 n-GaAs substrate
402 n-GaAs buffer layer
403 n-Al_0.9Ga_0.1As / Al_0.15Ga_0.85As lower semiconductor distributed Bragg reflector
403a n-Al_0.9Ga_0.1As lower semiconductor distributed Bragg reflector low refractive index layer
403b n-Al_0.15Ga_0.85As lower semiconductor distributed Bragg reflector high refractive index layer
404 n-AlAs selective oxidation layer
406 Al_0.15Ga_0.85As resonator spacer layer
406a Non-doped Al_0.15Ga_0.85As resonator spacer layer
406b Non-doped Al_0.15Ga_0.85As resonator spacer layer
406c p-Al_0.15Ga_0.85As resonator spacer layer
406d p-Al_0.15Ga_0.85As contact layer / resonator spacer layer
406e Non-doped Al_0.15Ga_0.85As resonator spacer layer
407 Non-doped GaAs / Al_0.15Ga_0.85As multiple quantum well structure
408 Non-doped Al_0.9Ga_0.1As / Al_0.15Ga_0.85As upper semiconductor distributed Bragg reflector
408a Non-doped Al_0.9Ga_0.1As upper semiconductor distributed Bragg reflector low refractive index layer
408b Non-doped Al_0.15Ga_0.85As upper semiconductor distributed Bragg reflector high refractive index layer
409 SiO₂Insulation film
411 p side electrode
412 n side electrode
413 Resonance region
414 Non-oxidized region
415 selective oxidation region
416 Ion implantation high resistance region
417 Ion non-implanted conduction region
501 n-GaAs substrate
502 n-GaAs buffer layer
503 n-AlAs / GaAs lower semiconductor distributed Bragg reflector
503a n-AlAs lower semiconductor distributed Bragg reflector low refractive index layer
503b n-GaAs lower semiconductor distributed Bragg reflector high refractive index layer
504 n-AlAs selective oxidation layer
506 GaAs resonator spacer layer
506a n-GaAs resonator spacer layer
506b n-GaAs resonator spacer layer
506c Non-doped GaAs resonator spacer layer
506d Non-doped GaAs resonator spacer layer
506e p-GaAs resonator spacer layer
506f p-GaAs contact layer
507 Non-doped GaInNAs / GaAs multiple quantum well structure
508 MgF₂/ ZnSe upper semiconductor distributed Bragg reflector
509 SiO₂Insulation film
511 p-side electrode
512 n-side electrode
513 resonance region
514 Non-oxidized region
515 Selective oxidation region
516 Ion implantation high resistance region
517 Ion non-implanted conduction region
601 Semi-insulating GaAs substrate
602 Non-doped GaAs buffer layer
603 Non-doped AlAs / GaAs lower semiconductor distributed Bragg reflector
603a Non-doped AlAs lower semiconductor distributed Bragg reflector low refractive index layer
603b Non-doped GaAs lower semiconductor distributed Bragg reflector high refractive index layer
604 n-AlAs selectively oxidized layer
606 GaAs resonator spacer layer
606a n-GaAs contact layer / resonator spacer layer
606b n-GaAs resonator spacer layer
606c n-GaAs resonator spacer layer
606d Non-doped GaAs resonator spacer layer
606e Non-doped GaAs resonator spacer layer
606f p-GaAs resonator spacer layer
606g p-GaAs contact layer / resonator spacer layer
606h Non-doped GaAs resonator spacer layer
607 Non-doped GaInNAs / GaAs multiple quantum well structure
608 Non-doped Al_0.8Ga_0.2As / GaAs upper semiconductor distributed Bragg reflector
608a Non-doped Al_0.8Ga_0.2As upper semiconductor distributed Bragg reflector low refractive index layer
608b Non-doped GaAs upper semiconductor distributed Bragg reflector high refractive index layer
611 p-side electrode
612 n-side electrode
613 Resonance region
614 Non-oxidized region
615 Selective oxidation region
616 Ion implantation high resistance region
617 Ion non-implanted conduction region
701 Semi-insulating GaAs substrate
702 Non-doped GaAs buffer layer
703 Non-doped Al_0.9Ga_0.1As / Al_0.5Ga_0.5As lower semiconductor distributed Bragg reflector
703a Non-doped Al_0.9Ga_0.1As lower semiconductor distributed Bragg reflector low refractive index layer
703b Non-doped Al_0.5Ga_0.5As lower semiconductor distributed Bragg reflector high refractive index layer
704 Non-doped AlAs selectively oxidized layer
706 (Al_0.5Ga_0.5)_0.5In_0.5P resonator spacer layer
706a non-doped- (Al_0.5Ga_0.5)_0.5In_0.5P resonator spacer layer
706b n- (Al_0.5Ga_0.5)_0.5In_0.5P contact layer / resonator spacer layer
706c n- (Al_0.5Ga_0.5)_0.5In_0.5P resonator spacer layer
706d non-doped (Al_0.5Ga_0.5)_0.5In_0.5P resonator spacer layer
706e non-doped (Al_0.5Ga_0.5)_0.5In_0.5P resonator spacer layer
706f p- (Al_0.5Ga_0.5)_0.5In_0.5P resonator spacer layer
706g p-GaAs contact layer
707 Non-doped GaInP / (Al_0.5Ga_0.5)_0.5In_0.5P multiple quantum well structure
708 TiO₂/ SiO₂Upper dielectric cloth Bragg reflector
711 p-side electrode
712 n-side electrode
713 Resonance region
714 Non-oxidized region
715 Selective oxidation region
716 High resistance region for ion implantation
717 Ion non-implanted conduction region
801 n-GaAs substrate
802 n-GaAs buffer layer
803 n-Al_0.8Ga_0.2As / GaAs lower semiconductor distributed Bragg reflector
803a n-Al_0.8Ga_0.2As lower semiconductor distributed Bragg reflector low refractive index layer
803b n-GaAs lower semiconductor distributed Bragg reflector high refractive index layer
804 Non-doped AlAs selectively oxidized layer
806 GaAs resonator spacer layer
806a Non-doped GaAs resonator spacer layer
806b Non-doped GaAs resonator spacer layer
806c p-GaAs resonator spacer layer
806d p-GaAs contact layer / resonator spacer layer
806e Non-doped GaAs resonator spacer layer
807 Non-doped GaInNAsSb / GaAs multiple quantum well structure
808 Non-doped Al_0.8Ga_0.2As / GaAs upper semiconductor distributed Bragg reflector
808a Non-doped Al_0.8Ga_0.2As upper semiconductor distributed Bragg reflector low refractive index layer
808b Non-doped GaAs upper semiconductor distributed Bragg reflector high refractive index layer
809 SiO₂Insulation film
811 p-side electrode
812 n-side electrode
813 Resonance region
814 Selective oxidation region
815 Non-oxidized region
816 Ion implantation high resistance region
817 Ion non-implanted conduction region
809 SiO₂Insulation film
901 Semi-insulating GaAs substrate
902 Non-doped GaAs buffer layer
903 Non-doped AlAs / GaAs lower semiconductor distributed Bragg reflector
903a Non-doped AlAs lower semiconductor distributed Bragg reflector low refractive index layer
903b Non-doped GaAs lower semiconductor distributed Bragg reflector high refractive index layer
904 Non-doped AlAs selectively oxidized layer
906 GaAs resonator spacer layer
906a Non-doped GaAs / resonator spacer layer
906b n-GaAs contact layer / resonator spacer layer
906c n-GaAs resonator spacer layer
906d Non-doped GaAs resonator spacer layer
906e Non-doped GaAs resonator spacer layer
906f p-GaAs resonator spacer layer
906g p-GaAs contact layer and resonator spacer layer
906h Non-doped GaAs resonator spacer layer
907 Non-doped GaInNAs / GaAs multiple quantum well structure
908 Non-doped Al_0.8Ga_0.2As / GaAs upper semiconductor distributed Bragg reflector
908a Non-doped Al_0.8Ga_0.2As upper semiconductor distributed Bragg reflector low refractive index layer
908b Non-doped GaAs upper semiconductor distributed Bragg reflector high refractive index layer
911 p-side electrode
912 n-side electrode
913 resonance region
914 Non-oxidized region
915 selective oxidation region
916 Ion implantation high resistance region
917 Ion non-implanted conduction region
1001 Semi-insulating GaAs substrate
1002 Non-doped GaAs buffer layer
1003 Non-doped AlAs / GaAs lower semiconductor distributed Bragg reflector
1003a Non-doped AlAs lower semiconductor distributed Bragg reflector low refractive index layer
1003b Non-doped GaAs lower semiconductor distributed Bragg reflector high refractive index layer
1004 n-AlAs selectively oxidized layer
1006 GaAs resonator spacer layer
1006a Undoped GaAs resonator spacer layer
1006b p-GaAs contact layer / resonator spacer layer
1006c p-GaAs resonator spacer layer
1006d Non-doped GaAs resonator spacer layer
1006e Non-doped GaAs resonator spacer layer
1006f n-GaAs resonator spacer layer
1006g n-GaAs resonator spacer layer
1006h n-GaAs contact layer / resonator spacer layer
1006i Non-doped GaAs resonator spacer layer
1007 Non-doped GaInNAs / GaAs multiple quantum well structure
1008 Non-doped Al_0.8Ga_0.2As / GaAs upper semiconductor distributed Bragg reflector
1008a Non-doped Al_0.8Ga_0.2As upper semiconductor distributed Bragg reflector low refractive index layer
1008b Non-doped GaAs upper semiconductor distributed Bragg reflector high refractive index layer
1011 n-side electrode
1012 p-side electrode
1013 Resonance region
1014 Non-oxidized region
1015 Selective oxidation region
1016 High resistance region of ion implantation
1017 Ion non-implanted conduction region
1101 n-GaAs substrate
1102 n-GaAs buffer layer
1103 n-Al_0.9Ga_0.1As / Al_0.15Ga_0.85As lower distribution Bragg reflector
1103a n-Al_0.9Ga_0.1As lower distributed Bragg reflector low refractive index layer
1103b n-Al_0.15Ga_0.85As lower distribution Bragg reflector high refractive index layer
1104 n-AlAs selectively oxidized layer
1105 Non-doped Al_0.15Ga_0.85As resonator spacer layer
1106 Non-doped GaAs / Al_0.15Ga_0.85As multiple quantum well active layer
1107 Non-doped Al_0.15Ga_0.85As resonator spacer layer
1108 p-Al_0.9Ga_0.1As / Al_0.15Ga_0.85As upper distributed Bragg reflector
1108a p-Al_0.9Ga_0.1As upper distributed Bragg reflector low refractive index layer
1108b p-Al_0.15Ga_0.85As upper distributed Bragg reflector high refractive index layer
1109 SiO₂Insulation layer
1110 Insulating resin
1111 p-side electrode
1112 n-side electrode
1113 Resonance region
1114 Non-oxidized region
1115 Selective oxidation region
1116 High resistance region of ion implantation
1117 Ion non-implanted conduction region
1201 p-GaAs substrate
1202 p-GaAs buffer layer
1203 p-Al_0.9Ga_0.1As / Al_0.15Ga_0.85As lower distribution Bragg reflector
1203a p-Al_0.9Ga_0.1As lower distributed Bragg reflector low refractive index layer
1203b p-Al_0.15Ga_0.85As lower distribution Bragg reflector high refractive index layer
1204 n-AlAs selectively oxidized layer
1205 non-doped Al_0.15Ga_0.85As resonator spacer layer
1206 Non-doped GaAs / Al_0.15Ga_0.85As multiple quantum well active layer
1207 Non-doped Al_0.15Ga_0.85As resonator spacer layer
1208 n-Al_0.9Ga_0.1As / Al_0.15Ga_0.85As upper distributed Bragg reflector
1208a n-Al_0.9Ga_0.1As upper distributed Bragg reflector low refractive index layer
1208b n-Al_0.15Ga_0.85As upper distributed Bragg reflector high refractive index layer
1209 SiO₂Insulation layer
1210 Insulating resin
1211 n-side electrode
1212 p-side electrode
1213 Resonance region
1214 Non-oxidized region
1215 Selective oxidation region
1216 High resistance region of ion implantation
1217 Ion non-implanted conduction region
1301 n-GaAs substrate
1302 n-GaAs buffer layer
1303 n-Al_0.8Ga_0.2As / GaAs lower semiconductor distributed Bragg reflector
1303a n-Al_0.8Ga_0.2As lower semiconductor distributed Bragg reflector low refractive index layer
1303b n-GaAs lower semiconductor distributed Bragg reflector high refractive index layer
1304 Non-doped AlAs selectively oxidized layer
1306 GaAs Cavity Spacer Layer
1306a Non-doped GaAs resonator spacer layer
1306b Non-doped GaAs resonator spacer layer
1306c p-GaAs resonator spacer layer
1306d p-GaAs contact layer / resonator spacer layer
1306e Non-doped GaAs resonator spacer layer
1307 Non-doped GaInNAs / GaAs multiple quantum well structure
1308 Non-doped Al_0.8Ga_0.2As / GaAs upper semiconductor distributed Bragg reflector
1308a Non-doped Al_0.8Ga_0.2As upper semiconductor distributed Bragg reflector low refractive index layer
1308b Non-doped GaAs upper semiconductor distributed Bragg reflector high refractive index layer
1309 SiO₂Insulation film
1311 p-side electrode
1312 n-side electrode
1313 Resonance region
1314 Selective oxidation region
1315 Non-oxidized region
1316 High resistance region of ion implantation
1317 Ion non-implanted conduction region
1401 n-GaAs substrate
1402 n-GaAs buffer layer
1403 n-Al_0.8Ga_0.2As / GaAs lower semiconductor distributed Bragg reflector
1403a n-Al_0.8Ga_0.2As lower semiconductor distributed Bragg reflector low refractive index layer
1403b n-Al_0.15Ga_0.85As lower semiconductor distributed Bragg reflector high refractive index layer
1404 n-AlAs selective oxidation layer
1406 GaAs resonator spacer layer
1406a Non-doped GaAs resonator spacer layer
1406b Non-doped GaAs resonator spacer layer
1406c p-GaAs resonator spacer layer
1406d p-GaAs contact layer / resonator spacer layer
1406e Non-doped GaAs resonator spacer layer
1407 Non-doped GaInNAs / GaAs multiple quantum well structure
1408 non-doped Al_0.8Ga_0.2As / GaAs upper semiconductor distributed Bragg reflector
1408a Non-doped Al_0.8Ga_0.2As upper semiconductor distributed Bragg reflector low refractive index layer
1408b Non-doped GaAs upper semiconductor distributed Bragg reflector high refractive index layer
1409 SiO₂Insulation film
1411 p-side electrode
1412 n side electrode
1413 Resonance region
1414 Non-oxidized region
1415 selective oxidation region
1416 Ion implantation high resistance region
1417 Ion non-implanted conduction region
1501 n-GaAs substrate
1502 n-GaAs buffer layer
1503 n-Al_0.8Ga_0.2As / GaAs lower semiconductor distributed Bragg reflector
1503a n-Al_0.8Ga_0.2As lower semiconductor distributed Bragg reflector low refractive index layer
1503b n-Al_0.15Ga_0.85As lower semiconductor distributed Bragg reflector high refractive index layer
1504 n-AlAs selective oxidation layer
1506 GaAs resonator spacer layer
1506a Non-doped GaAs resonator spacer layer
1506b Non-doped GaAs resonator spacer layer
1506c p-GaAs resonator spacer layer
1506d p-GaAs contact layer / resonator spacer layer
1506e Non-doped GaAs resonator spacer layer
1507 Non-doped GaInNAs / GaAs multiple quantum well structure
1508 Non-doped Al_0.8Ga_0.2As / GaAs upper semiconductor distributed Bragg reflector
1508a Non-doped Al_0.8Ga_0.2As upper semiconductor distributed Bragg reflector low refractive index layer
1508b Non-doped GaAs upper semiconductor distributed Bragg reflector high refractive index layer
1509 SiO₂Insulation film
1511 p-side electrode
1512 n side electrode
1513 Resonance region
1514 Non-oxidized region
1515 Selective oxidation region
1516 Ion implantation high resistance region
1517 Ion non-implanted conduction region
1601 n-GaAs substrate
1602 n-GaAs buffer layer
1603 n-Al_0.8Ga_0.2As / GaAs lower semiconductor distributed Bragg reflector
1604 n-AlAs selective oxidation layer
1605 p-AlAs selective oxidation layer
1606 GaAs resonator spacer layer
1607 Non-doped GaInNAs / GaAs multiple quantum well structure
1608 Non-doped Al_0.8Ga_0.2As / GaAs upper semiconductor distributed Bragg reflector
1611 resonance region
1612 Selective oxidation region
1613a Non-oxidized region
1613b Non-oxidized region
1614 SiO₂Insulation film
1615 p-side electrode
1616 n-side electrode
1701 n-GaAs substrate
1702 n-GaAs buffer layer
1703 n-Al_0.8Ga_0.2As / GaAs lower semiconductor distributed Bragg reflector
1704 Non-doped AlAs selectively oxidized layer
1706 GaAs resonator spacer layer
1707 Non-doped GaInNAs / GaAs multiple quantum well structure
1708 Non-doped Al_0.8Ga_0.2As / GaAs upper semiconductor distributed Bragg reflector
1709 SiO₂Insulation film
1711 p-side electrode
1712 n-side electrode
1713 Resonance region
1714a Non-oxidized region
1714b Non-oxidized region
1715 selective oxidation region
1716 Ion implantation high resistance region
1717 Ion non-implanted conduction region

Claims (19)

An active layer, a pair of distributed Bragg reflectors facing each other across the active layer, a hole path reaching the active layer from the first electrode, and an electron path reaching the active layer from the second electrode In surface emitting laser elements,
In the middle of the hole passage, a hole confinement that defines a hole injection region into the active layer, which is configured by a high resistance region provided by ion implantation and a conduction region surrounded by the high resistance region In addition to the hole confinement structure, a structure is provided that includes a selectively oxidized region formed by selectively oxidizing a semiconductor layer containing Al as a constituent element and a non-oxidized region surrounded by the selectively oxidized region. A surface emitting laser comprising a high-order transverse mode suppression structure, wherein a non-oxidized region of the high-order transverse mode suppression structure has a smaller area than a conduction region of the hole confinement structure element. 2. The surface emitting laser element according to claim 1, wherein the higher-order transverse mode suppressing structure is provided in the middle of the electron path. 2. The surface emitting laser element according to claim 1, wherein the high-order transverse mode suppression structure is provided to avoid the electron path and the hole path. 4. The surface emitting laser element according to claim 1, wherein the pair of distributed Bragg reflectors is made of a semiconductor material. 5. 4. The surface emitting laser element according to claim 1, wherein the pair of distributed Bragg reflectors are made of a semiconductor material and a dielectric material. 5. . 6. The surface-emitting laser device according to claim 1, wherein at least one of the pair of distributed Bragg reflectors includes an n-conductivity-type semiconductor Bragg reflector, and further includes an n-conductivity-type semiconductor. A surface emitting laser element comprising a tunnel junction between a Bragg reflector and an active layer. 6. The surface emitting laser element according to claim 1, wherein at least one of the pair of distributed Bragg reflectors is a non-doped semiconductor Bragg reflector or a part thereof. The Bragg reflector includes a region composed of a non-doped semiconductor Bragg reflector, and carriers are introduced into the non-doped semiconductor Bragg reflector or a semiconductor layer between the region composed of the non-doped semiconductor Bragg reflector and the active layer. A surface-emitting laser element comprising an electrode for injection. 8. The surface-emitting laser device according to claim 1, wherein a higher-order transverse mode suppression structure provided in the middle of the electron path, or a region that avoids the electron and hole paths. A surface-emitting laser element comprising a plurality of high-order transverse mode suppression structures provided therein. 9. The surface-emitting laser device according to claim 1, wherein the active layer includes at least one of Al, Ga, and In as a group III element constituting the active layer. A surface-emitting laser element comprising at least one of As and P as a group V element constituting a layer and having an oscillation wavelength shorter than 1.1 μm. 9. The surface-emitting laser device according to claim 1, wherein the active layer includes at least one of Ga and In as a group III element constituting the active layer. A surface emitting laser element comprising at least one of As, P, N, and Sb as a constituent V element, and having an oscillation wavelength longer than 1.1 μm. A surface-emitting laser array comprising the surface-emitting laser element according to any one of claims 1 to 10. 12. The surface-emitting laser array according to claim 11, wherein the surface-emitting laser array is composed of two or more types of surface-emitting laser elements having different oscillation wavelengths due to different areas of non-oxidized regions of the high-order transverse mode suppression structure. A surface emitting laser array characterized by comprising: 13. The surface emitting laser array according to claim 12, wherein each of the surface emitting laser elements constituting the surface emitting laser array includes a plurality of higher-order transverse mode suppression structures having two or more layers. Laser array. A surface-emitting laser module, wherein the surface-emitting laser element according to claim 1 or the surface-emitting laser array according to claim 11 is used. An electrophotographic system, wherein the surface emitting laser element according to any one of claims 1 to 10 or the surface emitting laser array according to claim 11 is used as a writing light source. An optical interconnection system, wherein the surface-emitting laser element according to any one of claims 1 to 10 or the surface-emitting laser array according to claim 11 is used as a light source. An optical communication system, wherein the surface-emitting laser element according to any one of claims 1 to 10 or the surface-emitting laser array according to claim 11 is used as a light source. 14. An optical communication system, wherein the surface emitting laser array according to claim 12 or 13 is used as a light source. A method of manufacturing a surface-emitting laser array including two or more types of surface-emitting laser elements having different oscillation wavelengths due to different areas of non-oxidized regions of a high-order transverse mode suppression structure. A method of manufacturing a surface emitting laser array, wherein the areas of non-oxidized regions of a high-order transverse mode control layer are made different by making the diameters of mesas including layers different.

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