JP2002261401A - Optical communication module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical communication module that is easy to produce and allows building of an inexpensive, reliable system. SOLUTION: Laser elements are fabricated so that a light-emitting portion is smaller than the cross-sectional area of the optical waveguide portion of an optical waveguide member, and are arranged at such density that a plurality of them can be present within the range of the cross-sectional area of the core of an optical fiber. On the face of a connector portion opposite the electrodes of lasers, an electrode pattern for connection is formed in specified size and shape for selectively connecting the electrodes for laser with electrodes for drive circuit for connection with an external drive circuit. When the connector portion is roughly positioned and placed on the laser element portion, only the laser elements in contact with the electrode pads for connection are connected with the external drive circuit. Thus, electrical connection including lasers that can be launched into individual optical fibers by at least the electrodes connected by the electrode pattern is implemented, and an optical module wherein optical transmission based on the laser elements driven by the external circuit is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser used for optical communication and the like and an optical communication system therefor, and more particularly to a so-called surface which emits light in a direction perpendicular to the surface of a semiconductor substrate used for manufacturing the semiconductor laser. The present invention relates to an optical communication module in which a plurality of laser elements are formed using a light emitting laser to enable large-capacity communication.

[0002]

2. Description of the Related Art A surface emitting semiconductor laser emits laser light in a vertical direction from the surface of a substrate, so that two-dimensional parallel integration is possible, and the spread angle of the output light is relatively narrow (about 10 degrees). Therefore, it is easy to couple with an optical fiber and easy to inspect the element.
Therefore, in particular, development as an element suitable for configuring an optical transmission module (optical interconnection device) of a parallel transmission type has been actively conducted. The immediate application of the optical interconnection device is parallel connection between housings of computers and the like and between boards, as well as short-distance optical fiber communication, but large-scale computer networks and long distances are expected applications in the future. There is a trunk system for distance and large-capacity communication.

Generally, a surface emitting semiconductor laser is made of GaAs.
Or, it is common to comprise an active layer made of GaInAs, and an optical resonator consisting of an upper semiconductor distributed Bragg reflector disposed above and below the active layer and a lower semiconductor distributed Bragg reflector on the substrate side. However, since the length of the optical resonator is significantly shorter than that of the edge emitting semiconductor laser, it is necessary to set the reflectivity of the reflecting mirror to an extremely high value (99% or more) so as to easily cause laser oscillation. There is. For this reason, a semiconductor distributed Bragg reflector formed by alternately laminating a low-refractive-index material made of AlAs and a high-refractive-index material made of GaAs with a period of 1/4 wavelength is usually used.

By the way, as described above, a long wavelength band laser having a laser wavelength of 1.1 μm or more used for optical communication, for example, a long wavelength band having a laser wavelength of 1.3 μm or 1.55 μm. In the laser, InP is used for the production substrate and InGaAsP is used for the active layer. However, the lattice constant of InP of the substrate is large, and a large difference in the refractive index cannot be obtained with a reflecting mirror material that matches the substrate. Must be more than pairs.

Another problem with semiconductor lasers formed on InP substrates is that the characteristics change significantly with temperature. For this reason, it is necessary to add a device for keeping the temperature constant, and it is difficult to use the device for general purposes such as consumer use. Light emitting semiconductors have not yet been put to practical use.

As an invention made to solve such a problem, one disclosed in Japanese Patent Application Laid-Open No. 9-237942 is known. According to this, a GaAs substrate is used as a production substrate, and a semiconductor layer made of AlInP that can be lattice-matched with the substrate is used as a low refractive index layer of at least one of the semiconductor distributed Bragg reflectors in the lower part on the substrate side. A semiconductor layer made of GaInNAs is used as a high refractive index layer of at least one of the lower and upper semiconductor distributed Bragg reflecting mirrors so that a larger refractive index difference is obtained than in the prior art. It is to realize a mirror.

Further, GaInNAs is used as a material for the active layer. This is because the band gap (forbidden band width) is increased from 1.4 eV to 0 eV by increasing the N composition.
0.85 μm
This is because it can be used as a material that emits a longer wavelength. In addition, since lattice matching with the GaAs substrate is possible, the semiconductor layer made of GaInNAs is 1.3 μm.
Reference is also made to the fact that it is preferable as a material for long-wavelength surface emitting semiconductor lasers in the m-band and 1.55 μm band.

[0008]

However, in the past, this has merely suggested the possibility of realizing a surface emitting semiconductor laser in a wavelength band longer than 0.85 μm, and such a device is actually realized. I haven't. This is because the basic configuration is almost theoretically determined, but a more specific configuration for realizing stable laser emission is still unknown.

As an example, a semiconductor distributed Bragg reflector formed by alternately laminating a low-refractive-index material made of AlAs and a high-refractive-index material made of GaAs at a period of 1/4 wavelength as described above is used. In the case of using a semiconductor layer made of AlInP capable of lattice-matching with the same substrate as the low-refractive index layer of the semiconductor distributed Bragg reflector, as disclosed in Japanese Unexamined Patent Application Publication No. 9-237942, The laser element does not emit light at all,
Alternatively, even if light is emitted, the light emission efficiency is low, which is far from a practical level. This is because the material containing Al is chemically very active, and crystal defects due to Al are likely to occur.

In order to solve this problem, Japanese Patent Application Laid-Open No. Hei 8-34
GaInNP and GaAs that do not contain Al as in the inventions disclosed in JP-A No. 0146 and JP-A-7-307525.
Therefore, there is a proposal for forming a semiconductor distributed Bragg reflector. However, the refractive index difference between GaInNP and GaAs is about half of the refractive index difference between AlAs and GaAs, and the number of stacked reflectors is very large, making it difficult to manufacture.

That is, at present, optical fiber communication is expected in a computer network or the like. A long wavelength band surface emitting semiconductor laser having a laser wavelength of 1.1 μm to 1.7 μm and a communication system using the same are available. It does not exist and its appearance is longing for.

Further, Japanese Patent Application Laid-Open No. H11-307868 discloses a method of constructing a module capable of easily optically coupling an optical fiber and a surface emitting laser. In this method, an electrode pattern for laser selection is set on the connector side, and at the time of assembly, one of the lasers that can be coupled to the optical fiber is selected by using the positional accuracy between the electrode pattern and the optical fiber. It has a structure.

However, although the method disclosed in Japanese Patent Application Laid-Open No. H11-307868 easily realizes optical coupling with a fiber, the coupling with a plurality of fibers such as an array fiber such as a tape fiber is performed by the method. In the case of batch processing, the incident position of the laser on the fiber core varies,
There remains a problem in communication quality such as a decrease in transmission speed due to a variation in signal strength between the fibers. Further, when the performance of the selected laser element is degraded, a problem remains in communication using the optical fiber to be coupled, and the yield as a module is lowered.

The present invention relates to a long-wavelength surface emitting semiconductor laser having a laser oscillation wavelength of 1.1 μm to 1.7 μm used for such optical communication and the like, and an optical communication system therefor. Proposes an optical communication module that uses a surface-emitting type semiconductor laser device chip that can lower operating voltage, oscillation threshold current, etc., as a light-emitting light source, and enables the construction of a highly productive, inexpensive, and highly reliable system. Is to do.

A second object is to use a long-wavelength surface emitting semiconductor laser device chip having a laser oscillation wavelength of 1.1 μm to 1.7 μm, which can be used stably, as a light emitting light source, which is excellent in productivity and inexpensive. An object of the present invention is to propose an optical communication system capable of constructing a highly reliable system.

A third object of the present invention is to provide a low cost optical communication module which is excellent in productivity and simplifies the process of assembling such an optical communication module.

A fourth object of the present invention is to propose an optical communication module having excellent productivity and excellent reliability in such an optical communication module.

A fifth object of the present invention is to propose an optical communication module which suppresses unnecessary light emission and is excellent in productivity and reliability in such an optical communication module.

A sixth object is to propose an inexpensive and highly reliable optical communication module in such an optical communication module.

Further, a seventh object is to manufacture such an optical communication module at low cost.

[0021]

According to the present invention, in order to achieve the above object, first, in a laser chip and an optical communication system connected to the laser chip, the laser chip has an oscillation wavelength of 1.1 μm to 1 μm. 0.7 μm, and the light-generating active layer is a layer whose main element is Ga, In, N, As or a layer consisting of Ga, In, As. What is claimed is: 1. A surface-emitting type semiconductor laser device chip having a resonator structure including a reflecting mirror provided at a lower portion, wherein the reflecting mirror periodically changes the refractive index of a material layer constituting the reflecting mirror to be small / large and is incident. A semiconductor distributed Bragg reflector for reflecting light by light wave interference, and the material layer having a small refractive index is made of AlxGa1-x.
As (0 <x ≦ 1), the material layer having a large refractive index is made of A
a reflecting mirror with lyGa1-yAs (0 ≦ y <x ≦ 1), and a material layer AlzGa1- between the small and large material layers having a refractive index between the small and large refractive indexes. zAs
(0 ≦ y <z <x ≦ 1) An optical communication module using a surface-emitting type semiconductor laser element chip provided with (0 ≦ y <z <x ≦ 1) as a light emitting light source, and two-dimensionally arranged at predetermined intervals on the laser chip. A plurality of laser light emitting elements and an electrically coupled electrode pattern corresponding to each of the laser light emitting elements are formed, and a member in which at least one or more optical waveguide members are arranged and held. An optical module formed by coupling, wherein the light-emitting portion of the laser light-emitting element is smaller than a cross-sectional area of the optical waveguide portion of the optical waveguide member, and is arranged at a density that can exist in the cross-sectional area. A means for selectively electrically coupling the plurality of electrodes corresponding to the plurality of laser light emitting elements optically coupled to the optical waveguide member is provided.

Secondly, in a laser chip and an optical communication system connected to the laser chip, the laser chip has an oscillation wavelength of 1.1 μm to 1.7 μm, and the active layer for generating light includes a main element. Is Ga, In, N, As
Or a layer made of Ga, In, As, and a surface emitting semiconductor laser device chip having a resonator structure including reflectors provided above and below the active layer in order to obtain a laser beam. The reflector is a semiconductor distributed Bragg reflector in which the refractive index of the material constituting the reflector changes periodically as small / large and reflects incident light by light wave interference. AlxGa1
−xAs (0 <x ≦ 1), and the material having the large refractive index is a reflector made of AlyGa1-yAs (0 ≦ y <x ≦ 1), and GaInP or GaInP is provided between the active layer and the reflector. An optical communication module using a surface-emitting type semiconductor laser device chip provided with a non-radiative recombination preventing layer made of GaInPAs as a light emitting light source, and two-dimensionally arranged at predetermined intervals on the laser chip. A plurality of laser light emitting elements and an electrically coupled electrode pattern corresponding to each of the laser light emitting elements are formed, and a member in which at least one or more optical waveguide members are arranged and held. An optical module formed by coupling, wherein a light-emitting portion of the laser light-emitting element is smaller than a cross-sectional area of an optical waveguide portion of the optical waveguide member and a plurality of light-emitting portions can exist in the cross-sectional area. In it has been arranged, and to the plurality of electrodes corresponding to a plurality of said laser light emitting element optically coupled to the optical waveguide member selectively providing means for electrically coupling.

Thirdly, in the first and second optical communication modules, each of the laser light emitting elements is provided on a surface of the member in which the optical waveguide members are arranged and held, the surface facing the light emitting element mounting substrate. There is provided an electrode pattern for making an electrical connection to an external circuit having a size capable of contacting at least two or more correspondingly electrically coupled electrode patterns.

Fourth, in the first and second optical communication modules, after the optical waveguide member and the light emitting element mounting substrate are set in a predetermined positional relationship, an external circuit for driving the light emitting element is provided. Before the connection to the light emitting element substrate, an electrode electrically connected to each light emitting element on the light emitting element substrate is driven, and light emission intensity information from the other emission end face of the optical waveguide member is used as a source. In addition, the electrode for connection to the external drive circuit and the electrode pattern electrically connected to each of the light emitting elements are selectively electrically connected.

Fifth, the first, second, and third
In the optical communication module of (1), an electrode pattern provided on a surface of the member in which the optical waveguide members are arranged and held and opposed to the light emitting element mounting substrate is electrically connected to each of the light emitting elements. Means for electrically contacting the pattern only within a predetermined range is provided.

Sixth, in the first to sixth optical communication modules, at least a part of the laser elements is arranged at irregular intervals.

Seventh, the first, second and third parts
In the above optical communication module, the laser light emitting device and the electrode pattern corresponding to each of the laser light emitting devices and electrically connected to each other are manufactured on separate substrates.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an example of a long-wavelength surface emitting semiconductor laser having a small laser oscillation wavelength of 1.1 to 1.7 .mu.m, which is a light emitting element applied to the optical communication system of the present invention, having a small transmission loss. This will be described with reference to FIG. As described above, a long-wavelength surface emitting semiconductor laser having a laser oscillation wavelength of 1.1 μm to 1.7 μm to which the present invention is conventionally applied only suggests the possibility. The material, as well as the more specific and detailed composition, were unknown. In the present invention, a material such as GaInNAs is used for the active layer, and a more specific configuration is clarified. The details are described below.

In the present invention, n-Ga having a plane orientation of (100) is used.
On the As substrate, n-AlxGa1- was formed at a thickness (thickness of λ / 4) of 発 振 of the oscillation wavelength λ in each medium.
xAs (x = 1.0) (low refractive index layer to low refractive index layer) and n-AlyGa1-yAs (y = 0) (high refractive index layer to high refractive index layer) were alternately laminated for 35 periods. An n-semiconductor distributed Bragg reflector (AlAs / GaAs lower semiconductor distributed Bragg reflector) is formed, and an n-GaxI having a thickness of λ / 4 is formed thereon.
n1-xPyAs1-y (x = 0.5, y = 1) layers were laminated. In this example, n-GaxIn1-xPyAs1-
The y (x = 0.5, y = 1) layer is also a part of the lower reflector and is a low refractive index layer (a layer having a small refractive index).

An undoped lower GaAs spacer layer, an active layer (quantum well active layer), which is a three-layer GaxIn1-xAs quantum well layer, and a GaAs barrier layer (2) are formed thereon.
0 nm) and an undoped upper GaAs spacer layer are laminated to form a resonator having a thickness of one oscillation wavelength λ (thickness of λ) in the medium.

Furthermore, p-doped C (carbon) is further added.
GaxIn1-xPyAs1-y (x = 0.5, y =
1) Layer and Zn-doped p-AlxGa1-xAs (x =
0) are alternately laminated with a thickness of １ ／ times the oscillation wavelength λ in each medium, and a periodic structure (one period) is laminated,
On top of this, C-doped p-AlxGa1-xAs (x =
0.9) and Zn-doped p-AlxGa1-xAs (x =
Semiconductor Bragg reflector (Al0.9Ga0.1As / GaAs upper semiconductor distributed Bragg) consisting of a periodic structure (25 periods) in which each layer is alternately laminated with a thickness of 1/4 of the oscillation wavelength λ in each medium. (Reflection mirror). In this example, p-GaxIn1-xPyAs1-y (x = 0.5,
The y = 1) layer is also a part of the upper reflecting mirror and is a low refractive index layer (a layer having a small refractive index).

Here, both the upper and lower reflecting mirrors are formed by alternately laminating a low refractive index layer (a layer having a small refractive index) / a high refractive index layer (a layer having a large refractive index). Between these, the material layer AlzG whose refractive index takes a value between small and large
a1−zAs (0 ≦ y <z <x ≦ 1) is provided. FIG. 2 shows a material layer AlzGa1-zAs (0) having a refractive index between a low refractive index and a high refractive index layer (high refractive index layer) between a low refractive index layer (low refractive index layer) and a high refractive index layer (high refractive index layer). FIG. 1 shows a part of a semiconductor distributed Bragg reflector provided with ≦ y <z <x ≦ 1 (not shown in FIG. 1 because the figure is complicated).

Conventionally, it has been studied to provide such a material layer for a semiconductor laser having a laser wavelength of 0.85 μm band, but it is still in the study stage, and the material, its thickness, etc. are described in detail. Not considered. Further, the laser oscillation wavelength as in the present invention is 1.1 μm to 1.7 μm.
No consideration has been given to a long-wavelength surface emitting semiconductor laser having a wavelength of m. The reason for this is that this field (a long-wavelength surface emitting semiconductor laser having a laser oscillation wavelength of 1.1 μm to 1.7 μm) is a new field, and little research has yet been made. The present inventor has quickly noticed the usefulness of this field (a long-wavelength surface emitting semiconductor laser having a laser oscillation wavelength of 1.1 μm to 1.7 μm and optical communication using the same), and intensively studied for realizing it. went.

In such a material layer, the refractive index of the material layer is changed continuously or stepwise by controlling the gas flow rate at the time of formation and changing the Al composition continuously or stepwise. And formed.

More specifically, AlzGa1-zAs
(0 ≦ y <z <x ≦ 1) The value of z of the layer is changed from 0 to 1.0, that is, GaAs to AlGaAs to AlA.
It is formed so that the ratio of Al and Ga changes gradually as in s. This is created by controlling the gas flow during layer formation as described above. Also, A
The same effect can be obtained by changing the ratio between 1 and Ga continuously as described above, or by changing the ratio stepwise.

The reason for providing such a material layer is to solve the problem that the electrical resistance of the p-semiconductor distributed Bragg reflector, which is one of the problems of the distributed Bragg reflector, is high. This is due to the hetero barrier generated at the interface between the two types of semiconductor layers constituting the semiconductor distributed Bragg reflector. However, as in the present invention, the interface between the low refractive index layer and the high refractive index layer is changed from one composition to the other. It is possible to suppress the generation of the hetero barrier by changing the Al composition gradually to the composition and changing the refractive index.

The material layer AlzGa1-zAs having such a refractive index between a small value and a large value (0 ≦ y <z <x ≦
1) The laser oscillation wavelength as in the present invention is 1.1 μm or more.
In the case of a long-wavelength surface emitting semiconductor laser of 1.7 μm, 5n
The thickness is preferably from m to 50 nm. If the thickness is smaller than this, there is a problem that the resistance becomes large and current does not easily flow, and the element generates heat and the driving energy becomes high. If the thickness is large, the resistance becomes small, which is advantageous in terms of heat generation of the element and driving energy. However, there is a problem that the reflectance cannot be obtained, and the optimum range (thickness of 5 nm to 50 nm) as described above. You need to choose

As described above, it has been considered to provide such a material layer for a conventional semiconductor laser having a laser wavelength in the 0.85 μm band. In the case of a long-wavelength surface emitting semiconductor laser having a wavelength of 1.7 μm, it is more effective. This is because, for example, in order to obtain the same reflectance (for example, 99.5% or more), the band from 1.1 μm to 1.0 μm is more than 0.85 μm.
In the case of the 7 μm band, such a material layer can be approximately doubled, so that the resistance value of the semiconductor distributed Bragg reflector can be reduced, the operating voltage, the oscillation threshold current, and the like are reduced, and the laser device This is advantageous in terms of preventing heat generation, stable oscillation, and low energy driving.

In other words, providing such a material layer on a semiconductor distributed Bragg reflector is particularly effective in the case of a long-wavelength surface emitting semiconductor laser having a laser oscillation wavelength of 1.1 μm to 1.7 μm as in the present invention. It can be said that it is a device.

An example of a more detailed examination result for obtaining an effective reflectance is, for example, in a 1.3 μm band surface emitting laser device, AlxGa1-xAs (x = 1.
0) (low refractive index layer to low refractive index layer) and AlyGa1-y
When As (y = 0) (high-refractive-index layer to high-refractive-index layer) is laminated for 20 periods, AlzGa1-zAs in which the reflectance of the semiconductor distributed Bragg reflector becomes 99.7% or less is obtained.
The thickness of the (0 ≦ y <z <x ≦ 1) layer is 30 nm. The wavelength band where the reflectance is 99.5% or more is 53 nm.
When the reflectance is designed to be 99.5% or more, ± 2
% Can be controlled. Therefore, when prototypes of 10 nm, 20 nm, and 30 nm which are equivalent to and thinner than this were prototyped, the reflectivity could be kept to a practically acceptable level, and the resistance value of the semiconductor distributed Bragg reflector could be reduced. A 1.3 μm band surface emitting laser device was realized, and laser oscillation was successful. Other configurations of the prototyped laser element are as described below.

In the multilayer mirror, there is a band having a high reflectance including the design wavelength (assuming that the film thickness can be completely controlled). It is referred to as a high-reflectance band (including a region where the reflectivity is equal to or more than a required value for a target wavelength). This is the region where the reflectance at the design wavelength is the highest and decreases very little as the wavelength increases. It drops off sharply from some area. Originally, it is necessary to completely control the film thickness of the multilayer mirror at the atomic layer level so that the reflectance is higher than the required reflectance for the target wavelength.

However, a film thickness error of about ± 1% actually occurs, so that the target wavelength deviates from the wavelength having the highest reflectance. For example, when the target wavelength is 1.3 μm, when the film thickness control is shifted by 1%, the wavelength having the highest reflectance is shifted by 13 nm. Therefore, it is desirable that the band of the high reflectance (here, the region where the reflectance is equal to or more than a required value with respect to a target wavelength) is wide. However, thickening the intermediate layer tends to narrow this band.

As described above, in a long-wavelength surface emitting semiconductor laser having a laser oscillation wavelength of 1.1 μm to 1.7 μm as in the present invention, the configuration of such a semiconductor distributed Bragg reflector is devised and optimized. Since the resistance value can be reduced while maintaining a high reflectance, the operating voltage, the oscillation threshold current, and the like can be reduced, so that heat generation of the laser element, stable oscillation, and low-energy driving can be achieved.

Referring again to FIG. 1, the uppermost p-AlxG
The a1-xAs (x = 0) layer also has a role as a contact layer (p-contact layer) for making contact with an electrode. Here, the In composition x of the quantum well active layer was 39% (Ga0.61In0.39As). The thickness of the quantum well active layer was 7 nm. The quantum well active layer is made of GaAs
It had a compression strain of about 2.8% with respect to the s substrate.

The whole surface emitting semiconductor laser was grown by MOCVD. In this case, no lattice relaxation was observed. The materials constituting each layer of the semiconductor laser include TMA (trimethylaluminum), TMG (trimethylgallium), TMI (trimethylindium),
AsH3 (arsine) and PH3 (phosphine) were used. H2 was used as a carrier gas. In the case where the strain is large as in the active layer (quantum well active layer) of the device shown in FIG. here,
The GaInAs layer (quantum well active layer) is grown at 550 ° C. The MOCVD method used here has a high degree of supersaturation and is suitable for crystal growth of a high strain active layer. In addition, high vacuum is not required as in the MBE method, and the supply flow rate and supply time of the source gas may be controlled.

In this example, a portion outside the current path was irradiated with protons (H +) to form an insulating layer (high-resistance portion), thereby forming a current narrowing portion. In this example, a p-side electrode is formed on the p-contact layer which is the uppermost layer of the upper reflector and is a part of the upper reflector, excluding the light emitting portion, and an n-side electrode is formed on the back surface of the substrate. Was formed.

In this example, the active region (in this embodiment, a resonator composed of the upper and lower spacer layers and the multiple quantum well active layer) sandwiched between the upper and lower reflectors and into which carriers are injected and recombined is used. In the material containing Al (II
The ratio of the low refractive index layer of the lower and upper reflectors closest to the active layer is G.
axIn1-xPyAs1-y (0 <x <1, 0 <y ≦
The non-radiative recombination preventing layer of 1) is used.

Since the carriers are confined between the low refractive index layers of the upper and lower reflectors, which are the wide gaps closest to the active layer, only the active region contains an Al-free layer (III
Even if the reflective mirror is configured to contain Al in the low refractive index layer (wide gap layer) of the reflector in contact with the active region even when the carrier is injected and recombined, Non-radiative recombination occurs at this interface, and the luminous efficiency decreases. Therefore, it is desirable that the active region be formed of a layer containing no Al.

The GaxIn1-xPyAs1-y
The non-radiative recombination preventing layer composed of (0 <x <1, 0 <y ≦ 1) layers has a lattice constant smaller than that of the GaAs substrate and has a tensile strain. In the epitaxial growth, the growth is performed by reflecting the information of the base, and if there is a defect on the surface of the substrate, it goes up to the growth layer. However, it is known that the presence of a strained layer is effective in preventing such defects from climbing.

When the above defects reach the active layer, the luminous efficiency is reduced. In the case of an active layer having a strain, there arises a problem that the critical thickness is reduced and a layer having a required thickness cannot be grown. In particular, when the amount of compressive strain of the active layer is large, for example, 2% or more, or when the thickness of the strained layer is larger than the critical thickness, even if non-equilibrium growth such as low-temperature growth is performed, growth cannot be performed due to the presence of defects. This is particularly problematic. If a strained layer is present, such a defect can be prevented from climbing up, so that the luminous efficiency can be improved, a layer having a compressive strain of 2% or more of the active layer can be grown, or the thickness of the strained layer can be reduced to a critical film. It becomes possible to grow thicker than thick.

This GaxIn1-xPyAs1-y (0 <
x <1, 0 <y ≦ 1) The layer is in contact with the active region and also has a role of confining carriers in the active region.
The In1-xPyAs1-y (0 <x <1, 0 <y ≦ 1) layer can have a larger band gap energy as the lattice constant decreases. For example, in the case of GaxIn1-xP (when y = 1), when x increases and approaches GaP, the lattice constant increases and the band gap increases.

The band gap Eg is determined by the direct transition.
(Γ) = 1.351 + 0.643x + 0.786x2, Eg in indirect transition
(X) = 2.24 + 0.02x. Therefore, the active region and GaxIn1-xPyAs1-y (0 <x <1, 0 <
Since the hetero barrier in the y ≦ 1) layer is large, carrier confinement is good, and there are effects such as a reduction in threshold current and an improvement in temperature characteristics.

Further, the GaxIn1-xPyAs1-y
The non-radiative recombination prevention layer composed of (0 <x <1, 0 <y ≦ 1) layers has a larger lattice constant than the GaAs substrate, has a compressive strain, and has a lattice constant of the active layer. G
axIn1-xPyAs1-y (0 <x <1, 0 <y ≦
1) It has a larger compressive strain than the layer.

The GaxIn1-xPyAs1-y
(0 <x <1, 0 <y ≦ 1) Since the direction of the strain of the layer is the same as that of the active layer, it works in the direction of reducing the substantial amount of compressive strain felt by the active layer. The larger the strain is, the more easily affected by external factors. Therefore, it is particularly effective when the amount of compressive strain of the active layer is as large as 2% or more, or when it exceeds the critical film thickness.

For example, a surface emitting laser having an oscillation wavelength in the 1.3 μm band is preferably formed on a GaAs substrate, and a semiconductor multilayer mirror is often used as a resonator, and the total thickness is 5 to 8 μm. It is necessary to grow 50 to 80 semiconductor layers before growing the active layer. (On the other hand, in the case of the edge emitting laser, the total thickness before growing the active layer is about 2 μm, and it is only necessary to grow about three semiconductor layers.)

In this case, even if a high-quality GaAs substrate is used, the surface of the GaAs substrate is caused by various causes (defects once generated basically crawl in the crystal growth direction and defects are generated at a hetero interface). The defect density on the surface immediately before the growth of the active layer is inevitably higher than the defect density of the active layer.
If the insertion of a strained layer or the substantial amount of compressive strain felt by the active layer is reduced before the growth of the active layer, the influence of defects on the surface immediately before the growth of the active layer can be reduced.

In this example, Al is not contained in the active region and in the interface between the reflector and the active region. Therefore, non-radiative recombination caused by crystal defects caused by Al during carrier injection is eliminated. And non-radiative recombination was reduced. As described above, it is preferable to apply the configuration including no Al at the interface between the reflector and the active region, that is, to provide a non-radiative recombination prevention layer for both the upper and lower reflectors. It is effective just to apply. In this example, both the upper and lower reflecting mirrors are semiconductor distributed Bragg reflecting mirrors, but one reflecting mirror may be a semiconductor distributed Bragg reflecting mirror and the other reflecting mirror may be a dielectric reflecting mirror. In the above-described example, only the layer closest to the active layer in the low-refractive-index layer of the reflector is G
axIn1-xPyAs1-y (0 <x <1, 0 <y ≦
Although the non-radiative recombination preventing layer of 1) is used, a plurality of Ga
xIn1-xPyAs1-y (0 <x <1, 0 <y ≦
1) may be a non-radiative recombination preventing layer.

Further, in this example, this idea is applied to the lower reflector between the GaAs substrate and the active layer, and a crystal defect caused by Al, which is a problem during the growth of the active layer, rises into the active layer. The adverse effect is suppressed, and the active layer can be crystal-grown with high quality. As a result, a surface-emitting type semiconductor laser having high luminous efficiency and sufficient reliability for practical use was obtained. In addition, not all of the low refractive index layers of the semiconductor distributed Bragg reflector but at least a portion closest to the active region is made of GaxIn1-xPyAs1-y containing no Al.
Since only (0 <x <1, 0 <y ≦ 1) layers are used, the above-described effect can be obtained without particularly increasing the number of stacked reflectors.

The oscillation wavelength of the surface emitting semiconductor laser manufactured in this manner was about 1.2 μm. GaInAs on a GaAs substrate has a longer wavelength due to an increase in the In composition, but with an increase in the amount of strain. Conventionally, up to 1.1 μm has been considered to be the limit of a longer wavelength (see the document “IEEE Photo”).
onics. Technol. Lett. Vol. 9
(1997) p. 1319-1321 ").

However, as manufactured by the inventor of the present invention, a high strain GaInAs quantum well active layer can be grown coherently thicker than before by a non-equilibrium growth method such as low temperature growth of 600 ° C. or less. Reached 1.2 μm. This wavelength is transparent to the Si semiconductor substrate. Therefore, light transmission through the Si substrate becomes possible in a circuit chip in which an electronic element and an optical element are integrated on the Si substrate.

As is apparent from the above description, it was found that a long-wavelength surface emitting semiconductor laser can be formed on a GaAs substrate by using GaInAs having a high In composition and a high compression strain for the active layer. As described above, such a surface emitting semiconductor laser can be grown by MOCVD, but other growth methods such as MBE can also be used. Although the triple quantum well structure (TQW) has been described as an example of the stacked structure of the active layer, a structure (SQW, MQW) using a quantum well of another number of wells may be used.

The structure of the laser may be another structure. Although the length of the resonator is set to the thickness of λ, it can be set to an integral multiple of λ / 2. Desirably, it is an integral multiple of λ. Also, an example in which GaAs is used as the semiconductor substrate has been described.
The above concept can be applied even when another semiconductor substrate such as P is used. The period of the reflecting mirror may be another period.

In this example, as the active layer, a layer whose main element is Ga, In, or As, that is, GaxIn1
Although an example of -xAs (GaInAs active layer) is shown, in order to perform laser oscillation of a longer wavelength, a layer (GaInNA) in which N is added and the main element is Ga, In, N, and As is used.
s active layer).

By actually changing the composition of the GaInNAs active layer, it was possible to perform laser oscillation in each of the 1.3 μm band and the 1.55 μm band. By studying the composition, a longer wavelength, for example, 1.7
A surface emitting laser in the μm band is also possible.

Further, when GaAsSb is used for the active layer,
A 1.3 μm band surface emitting laser can be realized on an aAs substrate. As described above, a semiconductor laser having a wavelength of 1.1 μm to 1.7 μm has not conventionally been available with a suitable material.
By using aInAs, GaInNAs, and GaAsSb, and providing a non-radiative recombination preventing layer, a high-performance surface emitting laser in a long wavelength region of the 1.1 μm to 1.7 μm band where stable oscillation has been difficult in the past. Can be realized.

Next, another configuration of a long wavelength band surface emitting semiconductor laser which is a light emitting element applied to the optical transmitting / receiving system of the present invention will be described with reference to FIG. Also in this case, FIG.
As in the case of (1), an n-GaAs substrate having a plane orientation of (100) is used. N-AlxGa1--thickness (1/4 thickness) of the oscillation wavelength? In each medium.
xAs (x = 0.9) and n-AlxGa1-xAs (x
= 0) to form an n-semiconductor distributed Bragg reflector (Al0.9Ga0.1As / GaAs lower reflector) in which 35 periods are alternately stacked,
N-GaxIn1-xPyAs having a thickness of λ / 4 thereon
1-y (x = 0.5, y = 1) layers were laminated. In this example, n-GaxIn1-xPyAs1-y (x = 0.5,
The y = 1) layer is also a part of the lower reflector and is a low refractive index layer.

On top of that, undoped lower GaAs
Spacer layer and three layers of GaxIn1-xNyAs1-y
Active layer (quantum well active layer) which is a quantum well layer and GaAs
A multi-quantum well active layer (a triple quantum well (TQW) in this example) composed of a barrier layer (15 nm) and an undoped upper GaAs spacer layer are stacked, and have a thickness corresponding to one oscillation wavelength in the medium. (Thickness of λ).

Further, a p-semiconductor distributed Bragg reflector (upper reflector) is formed thereon. The upper reflecting mirror is a low refractive index layer having a thickness of 3λ / 4 (a C-doped p-type layer having a thickness of (λ / 4-15 nm)) in which an AlAs layer serving as a selective oxidation layer is sandwiched between a GaInP layer and an AlGaAs layer. GaxI
n1-xPyAs1-y (x = 0.5, y = 1) layer, C
Doped p-AlzGa1-zAs (z = 1) layer to be selectively oxidized (thickness 30 nm), C-doped p-AlxGa1-xAs layer (x = 0.9) with thickness (2λ / 4-15 nm))
A GaAs layer (one period) having a thickness of λ / 4, a C-doped p-AlxGa1-xAs layer (x = 0.9) and a p-A
A semiconductor distributed Bragg reflector (Al0.x) having a periodic structure (22 periods) in which lxGa1-xAs (x = 0) layers are alternately stacked with a thickness of 1/4 of the oscillation wavelength in each medium. 9Ga0.1As / GaAs upper reflector).

Also in this example, although it is not shown in FIG. 3 because it becomes complicated in FIG. 3, the structure of the semiconductor distributed Bragg reflector has a low refractive index layer (low refractive index layer) as shown in FIG. Layer) and a high-refractive-index layer (high-refractive-index layer), a material layer AlzGa1 having a refractive index between a small value and a large value.
−zAs (0 ≦ y <z <x ≦ 1).

The uppermost p-AlxGa1-x
The As (x = 0) layer also has a role as a contact layer (p-contact layer) for making contact with the electrode. Here, the In composition x of the quantum well active layer is 37%,
The N (nitrogen) composition was 0.5%. The thickness of the quantum well active layer was 7 nm.

The surface-emitting type semiconductor laser was grown by MOCVD. The materials constituting each layer of the semiconductor laser include TMA (trimethylaluminum), TM
G (trimethylgallium), TMI (trimethylindium), AsH3 (arsine), PH3 (phosphine), and DMHy (dimethylhydrazine) were used as raw materials for nitrogen. DMHy decomposes at low temperature, so 600
It is suitable for low-temperature growth at a temperature of less than or equal to ° C., and is particularly preferable when growing a quantum well layer having a large strain that requires low-temperature growth. Note that H2 was used as a carrier gas.

In this example, the GaInNAs layer (quantum well active layer) was grown at 540 ° C. The MOCVD method has a high degree of supersaturation and is suitable for crystal growth of a material containing N and another V group simultaneously. In addition, high vacuum is not required as in the MBE method, and the supply flow rate and supply time of the source gas may be controlled.

Further, in this example, a mesa portion having a predetermined size is formed by p-GaxIn1-xPyAs1-y (x = 0.
5, y = 1) p-AlzGa1-zA until the layer is reached
s (z = 1) is formed by exposing the side surface of the selective oxidation layer,
The AlzGa1-zAs (z = 1) layer on the side surface is oxidized from the side surface with water vapor to form an AlxOy current narrowing layer.

Finally, the portion removed by mesa etching with a polyimide (insulating film) is buried and flattened, the polyimide on the upper reflector is removed, and a p-side electrode is formed on the p-contact layer except for the light emitting portion. And n on the back surface of the GaAs substrate.
Side electrodes were formed.

In this example, below the layer to be selectively oxidized, GaxIn1-xPyAs1-
The y (0 <x <1, 0 <y ≦ 1) layer is inserted. For example, in the case of wet etching, if a sulfuric acid-based etchant is used, a GaInPAs-based material can be used as an etching stop layer with respect to an AlGaAs-based material.
axIn1-xPyAs1-y (0 <x <1, 0 <y ≦
1) By inserting the layer, the height of mesa etching for selective oxidation can be strictly controlled. Therefore, uniformity and reproducibility can be improved, and cost can be reduced.

When the surface-emitting type semiconductor laser (element) of this example is integrated one-dimensionally or two-dimensionally, the controllability at the time of manufacturing the element is improved, and the uniformity of the element characteristics of each element in the array is improved. In addition, there is an effect that reproducibility becomes extremely good. In this example, GaxIn1-xPyAs1-y (0 <x <
Although the 1,0 <y ≦ 1) layer is provided on the upper reflecting mirror side, it may be provided on the lower reflecting mirror side.

Also in this example, in the active region (in this embodiment, a resonator composed of the upper and lower spacer layers and the multiple quantum well active layer) sandwiched between the upper and lower reflecting mirrors and into which carriers are injected and recombined, In the active region, a material containing Al is not used, and the lower refractive index layers of the lower and upper reflectors, which are closest to the active layer, are made of GaxIn1-xPyAs1.
A non-radiative recombination preventing layer of -y (0 <x <1, 0 <y ≦ 1). That is, in this example, Al is not included in the active region and at the interface between the reflecting mirror and the active region, so that non-radiative recombination caused by crystal defects caused by Al during carrier injection is reduced. Can be done.

It is preferable to apply a structure in which Al is not contained at the interface between the reflecting mirror and the active region to the upper and lower reflecting mirrors as in this example, but it is effective to apply the structure to only one of the reflecting mirrors. . In this example, both the upper and lower reflecting mirrors are semiconductor distributed Bragg reflecting mirrors, but one reflecting mirror may be a semiconductor distributed Bragg reflecting mirror and the other reflecting mirror may be a dielectric reflecting mirror.

Further, also in this example, the same idea as in the case of the example of FIG. 1 is applied to the lower reflector between the GaAs substrate and the active layer, so that crystal defects caused by Al which are problematic at the time of growing the active layer. Of the active layer is suppressed, and crystal growth of the active layer with high quality can be achieved.

Incidentally, such a non-radiative recombination preventing layer is
1 and 3, a part of the semiconductor distributed Bragg reflector is formed, and its thickness is 、 of the oscillation wavelength λ in the medium (thickness of λ / 4). ). Alternatively, a plurality of layers may be provided.

As is clear from the above description, a surface emitting semiconductor laser having high luminous efficiency and sufficient reliability for practical use was obtained by such a configuration. Also, not all of the low refractive index layers of the semiconductor distributed Bragg reflector, but at least a portion closest to the active region is made of GaxIn containing no Al.
Since only the non-radiative recombination preventing layer of 1-xPyAs1-y (0 <x <1, 0 <y ≦ 1) was used, the above-mentioned effect could be obtained without particularly increasing the number of stacked reflectors. .

Even with such a structure, since the polyimide can be easily embedded, the wiring (p-side electrode in this example) is hardly disconnected, and a device having high reliability can be obtained. The oscillation wavelength of the surface emitting semiconductor laser manufactured in this manner was about 1.3 μm.

In this example, the main elements are Ga, In,
A layer composed of N and As was used as an active layer (GaInNAs
As a result, a long-wavelength surface emitting semiconductor laser could be formed on the GaAs substrate. Further, the current was narrowed by selective oxidation of the selectively oxidized layer containing Al and As as main components, so that the threshold current was low.

According to the current narrowing structure using the current narrowing layer made of the Al oxide film obtained by selectively oxidizing the selectively oxidized layer,
By forming the current narrowing layer close to the active layer, the spread of current can be suppressed, and carriers can be efficiently confined in a minute region that is not exposed to the atmosphere. Further oxidized to Al
By forming an oxide film, the refractive index is reduced, and light can be efficiently confined in a minute region in which carriers are confined by the effect of the convex lens, and the efficiency is extremely improved, and the threshold current can be reduced. In addition, since the current narrowing structure can be easily formed, the manufacturing cost can be reduced.

As is clear from the above description, even in the configuration shown in FIG. 3, a 1.3 μm band surface-emitting type semiconductor laser can be realized as in the case of FIG. Is obtained. The surface emitting semiconductor laser of FIG. 3 can be grown by MOCVD as in the case of FIG. 1, but other growth methods such as MBE can be used. Although DMHy is used as the nitrogen source, activated nitrogen and other nitrogen compounds such as NH 3 can be used.

Further, an example of a triple quantum well structure (TQW) has been shown as a laminated structure of the active layer. However, a structure using other quantum wells (SQW, DQW, MQW) or the like can also be used. The structure of the laser may be another structure.

In the surface-emitting type semiconductor laser shown in FIG. 3, by changing the composition of the GaInNAs active layer, 1.
A surface emitting semiconductor laser in the 55 μm band, and even in the longer wavelength 1.7 μm band, is also possible. The GaInNAs active layer may contain other III-V elements such as Tl, Sb, and P. Also, even if GaAsSb is used for the active layer, a 1.3 μm band surface emitting semiconductor laser can be realized on a GaAs substrate.

When GaInAs is used for the active layer,
Conventionally, up to 1.1 μm has been considered to be the limit of increasing the wavelength.
The quantum well active layer can be grown thicker than before, and the wavelength can reach up to 1.2 μm. in this way,
Conventionally, there is no suitable material for the semiconductor laser having a wavelength of 1.1 μm to 1.7 μm, but GaInAs, G
By using aInNAs and GaAsSb and providing a non-radiative recombination prevention layer, a high-performance surface-emitting laser can be realized in the long wavelength region of the 1.1 μm to 1.7 μm wavelength band where stable oscillation has conventionally been difficult. As a result, application to optical communication systems has become possible.

FIG. 4 shows an example in which such a long wavelength band surface emitting semiconductor laser device is formed as a large number of chips on an n-GaAs wafer having a plane orientation of (100), and a laser device chip. In the laser element chip shown here, 1 to n laser elements are formed, and the number n and the arrangement method are determined according to the application.

FIG. 5 shows an example of an optical communication module using a long wavelength band surface emitting semiconductor laser. In the present invention, electrodes corresponding to a plurality of the above surface emitting laser elements in a one-to-one correspondence are monolithically formed on the same semiconductor substrate. An element substrate manufactured at a predetermined interval and an electrode pattern for connecting to an external laser drive circuit are formed on the substrate or on another substrate, and are electrically connected to the module substrate on a module substrate. The optical module is constituted by a structure in which an optical waveguide member (optical fiber in the embodiment) to be optically coupled and a connector member for fixing the optical waveguide member are arranged in a predetermined arrangement.

At this time, the laser element is manufactured such that its light emitting portion is smaller than the cross-sectional area of the optical waveguide portion of the optical waveguide member, and the laser element has a density which can exist within a range of the core cross-sectional area of the optical fiber. It is arranged in. A connection electrode pattern of a predetermined size and shape for selectively connecting the laser electrode and a drive circuit electrode connected to the external drive circuit on a surface of the connector portion facing the laser electrode. Is installed.

The connection electrode has a size and a shape that can be connected to at least two or more of the laser electrodes. When the optical fiber is mounted on the module substrate together with the connector, the fiber and the connection electrode are connected to each other. By setting the positional relationship with the connection electrode, for example, the distance between the center of the fiber core and the center of the connection electrode pad = the distance between the laser electrode and the laser element, the optical fiber can be optically connected to the core. It is possible to electrically connect the laser electrodes corresponding to the plurality of laser elements and the corresponding electrodes for external drive circuit connection, and to selectively drive the plurality of lasers optically coupled to the optical fiber and the external drive. Communication is performed by connecting a circuit and driving the laser element as a pair of laser elements during communication.

A more specific description will be given with reference to FIGS. 6 and 7. In this embodiment, the laser elements are manufactured by being arranged two-dimensionally on an array. Now, let L be the distance between the center of gravity of the light emitting surface of one laser element and the center of gravity of the corresponding pad portion of the laser electrode. At this time, the center of gravity of the connection electrode pad is set in a direction perpendicular to the fiber arrangement direction from the center of the optical fiber so that the distance from the center of the core is L, and is larger than the laser electrode. At the same time, the electrode pad is formed in such a size that it can contact two or more of the electrodes.

The pad portion of the laser electrode and the connection electrode pad are formed larger in the height direction than other wiring patterns, or the other wiring portions are protected by an insulating film or the like. Prevent unnecessary connections.

When the connector section is roughly positioned and installed on the laser element section, only the laser element contacted with the connection electrode pad is connected to the external drive circuit. At this time, unless the fiber arrangement direction is greatly inclined with respect to the laser arrangement (this is not shown, a guide hole is formed in the module substrate,
Rough alignment can be realized by placing pins at predetermined positions on the connector side and inserting the pins into the guides.) At least, among the electrodes to which the electrode pattern is connected, individual optical fibers An electrical connection including a laser that can be incident is possible. Therefore, an optical module capable of transmitting light using a laser element driven by an external circuit can be realized.

FIGS. 8 and 9 show another embodiment. In this embodiment, unlike the above embodiment, no connection electrode pattern is set on the connector side. Instead, as shown in FIG. 9, a module is manufactured by installing an optical fiber and then selectively connecting the external drive circuit connecting electrode pattern with a wire using a connection device such as wire bonding.

That is, after assembling the fiber connector and the element substrate, power is supplied from the common electrode and the laser electrode of the laser element substrate by a probe electrode or the like connected to an external power supply, and the laser is individually oscillated. The intensity of light emitted from the other end of the fiber is monitored. Electrode data at which a desired optical power is obtained from the laser electrode and light intensity at that time is stored, and based on the data, a bonding apparatus is used to selectively wire-connect to an external drive circuit connection electrode pattern. With this method, it is also possible to complete the module inspection and the assembly at the same time.

FIG. 10 shows another embodiment. In this embodiment, as in the above embodiment, the laser elements are not evenly arranged, but the light emitting element is set in accordance with the installation interval of the optical waveguide members installed facing each other and the accuracy of the relative installation position with the laser element substrate. By making the arrangement of some irregular intervals, the manufacturing cost can be reduced by thinning out the laser element of the portion where the optical waveguide member is not originally installed at the time of fabrication, or the optical waveguide member can be reduced in accordance with the assembling accuracy. By arranging the laser elements densely in the portion where the probability of opposition is high, it is possible to suppress variations in coupling efficiency.

In the examples shown in FIGS. 5 to 10, a plurality of surface-emitting type semiconductor laser devices and electrode patterns (laser electrodes) electrically corresponding to each of them are mounted on the same chip. Although it is formed, it is also possible to separately form a chip for forming a surface emitting semiconductor laser element and a chip for forming an electrode pattern (electrode for laser). Since the surface-emitting type semiconductor laser device used in the module of the present invention is manufactured on an expensive GaAs substrate as described above, it is manufactured on a separate substrate as described above, and an electrode pattern (electrode for laser) is formed. Is formed on an inexpensive Si substrate, the manufacturing cost of this module can be greatly reduced.

[0100]

[Effect of the Invention] [Claim 1 to the corresponding Effect] computer networks, the laser oscillation wavelength trunk lines such as fiber optic communications is expected long-distance large-capacity communications 1.1
In the field of the μm band to the 1.7 μm band, there has been no surface emitting semiconductor laser capable of lowering the operating voltage, the oscillation threshold current and the like, generating less heat from the laser element and performing stable oscillation, and a communication system using the same. However, by devising a semiconductor distributed Bragg reflector as in the present invention, the operating voltage, oscillation threshold current, and the like can be reduced, the laser element generates less heat, and stable oscillation can be achieved. The system has been realized. Furthermore, by adopting a structure that relaxes the required accuracy at the time of assembly, an optical communication module that is capable of constructing a system that is excellent in productivity, inexpensive and highly reliable can be realized.

[Effects Corresponding to Claim 2] The laser oscillation wavelength at which optical fiber communication is expected to be 1.1 μm, such as a computer network, a trunk system for long-distance large-capacity communication, etc.
In the field of m band to 1.7 μm band, there is no long wavelength band surface emitting semiconductor laser that can be used stably and a communication system using the same. By using the surface emitting semiconductor laser device chip thus provided, stable oscillation became possible, and a practical optical communication system using this as a light emitting light source was realized. Furthermore, by adopting a structure that relaxes the required accuracy at the time of assembly, an optical communication module that is capable of constructing a system that is excellent in productivity, inexpensive and highly reliable can be realized.

[Effects Corresponding to Claim 3] In such an optical communication system, the module assembling process is simplified, and an inexpensive optical communication module with high productivity can be realized.

[Effects Corresponding to Claim 4] In such an optical communication system, an inexpensive optical communication module having excellent productivity can be realized by integrating the module assembly and the inspection process.

[Effects Corresponding to Claim 5] In such an optical communication system, unnecessary light emission is suppressed, and an optical communication module excellent in productivity and reliability can be realized.

[Effects Corresponding to Claim 6] In such an optical communication module, the manufacturing cost is reduced and the cost is reduced.
An optical communication module with excellent reliability was realized.

[Effects Corresponding to Claim 7] In such an optical communication module, the surface-emitting type semiconductor laser elements and the electrode patterns (laser electrodes) electrically corresponding to each of them are separated from each other. Since the module is manufactured on a substrate, the manufacturing cost of the module can be greatly reduced, and an inexpensive and highly reliable optical communication module can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view of an element part of a long-wavelength band surface emitting semiconductor laser according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of a configuration of a semiconductor distributed Bragg reflector of a long wavelength band surface emitting semiconductor laser according to an embodiment of the present invention.

FIG. 3 is a sectional view of an element portion of another configuration of a long-wavelength band surface emitting semiconductor laser according to an embodiment of the present invention.

FIG. 4 is a plan view showing a wafer substrate and a laser element chip on which a long wavelength band surface emitting semiconductor laser element according to one embodiment of the present invention is formed.

FIG. 5 is a perspective view showing an optical communication module using a long-wavelength band surface emitting semiconductor laser device according to one embodiment of the present invention.

FIG. 6 is a schematic diagram showing an optical communication module using a long-wavelength band surface emitting semiconductor laser device according to one embodiment of the present invention.

FIG. 7 is a schematic diagram showing a cross section of an optical communication module using a long wavelength band surface emitting semiconductor laser device according to one embodiment of the present invention.

FIG. 8 is a schematic diagram showing an optical communication module using a long wavelength band surface emitting semiconductor laser device according to an embodiment of the present invention.

FIG. 9 is a schematic diagram of a system for assembling an optical communication module according to an embodiment of the present invention.

FIG. 10 is a schematic diagram showing an optical communication module using a long-wavelength band surface emitting semiconductor laser device according to an embodiment of the present invention.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuya Miyagaki 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company, Ltd. (72) Inventor Ken Kanai 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Atsuyuki Watada 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Yukie Suzuki 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Inventor Satoru Sugahara 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Shunichi Sato 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Invention Person Shuichi Hikiji 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Takuro Sekiya 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company In Ricoh (72) Inventor Shinji Sato 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (Reference) 2H037 AA01 BA05 CA34 DA04 5F073 AB17 AB28 BA01 CA07 CA17 CB02 DA05 DA23 EA15 EA23 FA01 FA07 FA11 GA01

Claims (7)

[Claims] In a laser chip and an optical communication system connected to the laser chip, the laser chip has an oscillation wavelength of 1.1 μm to 1.7 μm, and an active layer for generating light includes a main element of Ga, A surface emitting type having a layer structure of In, N, and As or a layer of Ga, In, and As and having a resonator structure including reflectors provided above and below the active layer to obtain a laser beam. A semiconductor laser element chip, wherein the reflecting mirror is a semiconductor distributed Bragg reflecting mirror that periodically changes a refractive index of a material layer constituting the reflecting mirror to small / large and reflects incident light by light wave interference; The material layer having a small ratio is AlxGa1-xA.
s (0 <x ≦ 1), and the material layer having a large refractive index is made of Al
a reflecting mirror having yGa1-yAs (0 ≦ y <x ≦ 1), and a material layer AlzGa1- between the material layers having the small and large refractive indices, the refractive index of which takes a value between the small and large. zAs (0
≦ y <z <x ≦ 1) in the form of an optical communication module using a surface-emitting type semiconductor laser element chip as a light emitting source, and a plurality of two-dimensionally arranged at predetermined intervals on the laser chip. A laser light emitting element and an electrically coupled electrode pattern corresponding to each of the laser light emitting elements are formed, and a member in which at least one or more optical waveguide members are arranged and held is connected. In the optical module, the light emitting portion of the laser light emitting element is smaller than the cross-sectional area of the optical waveguide portion of the optical waveguide member,
And the plurality of electrodes corresponding to the plurality of laser light emitting elements which are arranged at a density that can exist in the cross-sectional area and are optically coupled to the optical waveguide member are selectively electrically coupled. An optical communication module, comprising: 2. In a laser chip and an optical communication system connected to the laser chip, the laser chip has an oscillation wavelength of 1.1 μm to 1.7 μm, and has an active layer for generating light, wherein the main element is Ga, A surface emitting type having a layer structure of In, N, and As or a layer of Ga, In, and As and having a resonator structure including reflectors provided above and below the active layer to obtain a laser beam. A semiconductor laser device chip, wherein the reflecting mirror is a semiconductor distributed Bragg reflecting mirror that periodically changes the refractive index of a material forming the reflecting mirror to small / large and reflects incident light by light wave interference; But the material is AlxGa1-xAs
(0 <x ≦ 1), and the material having a large refractive index is AlyG
a1-yAs (0 ≦ y <x ≦ 1),
GaInP or Ga between the active layer and the reflector.
There is an optical communication module using a surface-emitting type semiconductor laser device chip provided with a non-light emitting recombination preventing layer made of InPAs as a light emitting source, and a plurality of two-dimensionally arranged at predetermined intervals on the laser chip. A laser light emitting element and an electrically coupled electrode pattern corresponding to each of the laser light emitting elements are formed, and a member in which at least one or more optical waveguide members are arranged and held is connected. An optical module, wherein the light emitting portions of the laser light emitting element are arranged at a density that is smaller than a cross-sectional area of the optical waveguide portion of the optical waveguide member and a density that can exist in the cross-sectional area. An optical communication module comprising means for selectively electrically coupling the plurality of electrodes corresponding to the plurality of laser light emitting elements optically coupled to a member. Yuru. 3. At least two or more electrode patterns electrically coupled to each of the laser light emitting elements are provided on a surface of the member on which the optical waveguide members are arranged and held and facing the light emitting element mounting substrate. 3. The optical communication module according to claim 1, further comprising an electrode pattern for making an electrical connection to an external circuit having a size capable of contacting the optical communication module. 4. In the optical communication module, after setting the optical waveguide member and the light emitting element mounting board in a predetermined positional relationship, before connecting to an external circuit for driving the light emitting element, Driving electrodes electrically coupled to the respective light emitting elements on the light emitting element substrate to connect to the external drive circuit based on light emission intensity information from the other emission end face of the optical waveguide member 3. The optical communication module according to claim 1, wherein an electrode and an electrode pattern corresponding to each of the light-emitting elements and electrically coupled thereto are selectively electrically connected. 5. In the optical communication module, an electrode pattern provided on a surface of the member, in which the optical waveguide members are arranged and held, facing the light emitting element mounting substrate, and an electrical pattern corresponding to each of the light emitting elements. The optical communication module according to any one of claims 1 to 3, further comprising means for making electrical contact with an electrode pattern coupled to the first electrode only within a predetermined range. 6. The optical communication module according to claim 1, wherein the laser elements are arranged at least partially at unequal intervals.
The optical communication module according to the item. 7. The laser light emitting device according to claim 1, wherein said laser light emitting device and an electrode pattern corresponding to each of said laser light emitting devices and electrically connected thereto are manufactured on separate substrates. The optical communication module as described in the above.