JP2007221020A - Surface-emitting laser element, surface-emitting laser array having it, image forming device having either the element or the array, light pickup apparatus having either the element or the array, light transmitting module having either the element or the array, light transmitting/receiving module having either the element or the array and light communication system having both the element and the array - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface-emitting laser element which exhibits a high output and has an excellent characteristic of temperature. <P>SOLUTION: The surface-emitting laser element has a reflection layer 102 composed of a semiconductor-distributed Bragg reflector. The reflection layer 102 is formed on a substrate, and is composed of a structure in which a layer 1021 of low index of refraction and a layer 1022 of high index of refraction are alternately laminated. The number of layers of the layer 1021 of low index of refraction and the layer 1022 of high index of refraction is periods of 40.5. Each of film thicknesses of the layer 1021 of low index of refraction and the layer 1022 of high index of refraction is one fourth of an oscillating wavelength λ of the surface-emitting laser element. The layer 1021 of low index of refraction is composed of n-Al<SB>0.9</SB>Ga<SB>0.1</SB>As, and the layer 1022 of high index of refraction is composed of n-Ga<SB>0.5</SB>In<SB>0.5</SB>P of the smallest thermal resistivity among AlGaInP lattice-matching with GaAs. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a surface emitting laser element, a surface emitting laser array including the surface emitting laser element, an image forming apparatus including the surface emitting laser element or the surface emitting laser array, an optical pickup apparatus including the surface emitting laser element or the surface emitting laser array, The present invention relates to an optical transmission module including a surface emitting laser element or a surface emitting laser array, an optical transmission / reception module including a surface emitting laser element or a surface emitting laser array, and an optical communication system including a surface emitting laser element or a surface emitting laser array. is there.

  A surface-emitting laser element (surface-emitting semiconductor laser element) is a semiconductor laser that emits light in a direction perpendicular to a substrate, and provides high-performance characteristics at a lower cost than an edge-emitting type. It is used in consumer applications such as a light source for optical communication such as interconnection, a light source for an optical pickup, and a light source for an image forming apparatus.

  In particular, surface emitting laser elements in the 850 nm band and the 980 nm band have good carrier confinement in the active layer. More specifically, in the 850 nm band surface emitting laser element, a quantum well active layer made of gallium arsenide (GaAs), a barrier layer made of aluminum gallium arsenide (AlGaAs), and a spacer (cladding layer) are used. Yes.

  Further, in a surface emitting laser element in the 850 nm band, a high-performance AlGaAs-based reflector (semiconductor multilayer film reflector, semiconductor distributed Bragg reflector, and semiconductor DBR) and a current confinement structure using an Al oxide film are provided. Since it can be used, it achieves a practical level of performance.

  However, since the surface emitting laser element has a small volume of the active layer, the optical output is small compared to the edge emitting laser, and an increase in output is often required. In particular, the shorter the wavelength, the worse the carrier confinement in the active layer, and the higher output cannot be obtained, and the temperature characteristics deteriorate.

  A short-wavelength surface emitting laser element having an oscillation wavelength band of 780 nm employs a current confinement structure in which an AlAs layer is selectively oxidized (Non-Patent Document 1). The surface emitting laser element disclosed in Non-Patent Document 1 has a structure in which a resonator composed of an active layer and a spacer layer sandwiching the active layer is sandwiched between a lower reflecting mirror and an upper reflecting mirror.

The thickness of the resonator is one wavelength of the oscillation wavelength. The active layer has a quantum well structure in which well layers made of Al _0.12 Ga _0.88 As and barrier layers made of Al _0.3 Ga _0.7 As are alternately stacked. The spacer layer is made of Al _0.6 Ga _0.4 As. Further, the lower reflecting mirror includes a high refractive index layer made of n-type Al _0.3 Ga _0.7 As and a low refractive index layer made of n-type Al _0.9 Ga _0.1 As. It consists of a stacked structure. In this case, the film thickness per layer of the high refractive index layer and the low refractive index layer is λ / 4 where λ is the oscillation wavelength of the surface emitting laser element.

Further, the upper reflecting mirror is a stack of 24 pairs of a high refractive index layer made of p-type Al _0.3 Ga _0.7 As and a low refractive index layer made of p-type Al _0.9 Ga _0.1 As. It consists of the structure. Also in this case, the film thickness per layer of the high refractive index layer and the low refractive index layer is λ / 4.

  In addition, an AlAs selective oxide layer is provided in the upper reflecting mirror at a distance of λ / 4 from the resonator. In addition, in order to reduce resistance, the composition gradient layer from which a composition changes gradually is provided between each layer of a reflective mirror.

  The above-described active layer, spacer layer, and the like are formed by MOCVD (Metal Organic Chemical Deposition) method or MBE (Molecular Beam Epitaxy) method.

  The surface emitting laser element disclosed in Non-Patent Document 1 employs a mesa shape. In this mesa shape, the lower reflector, spacer layer, active layer, spacer layer, and upper reflector are sequentially stacked on the substrate, and then the upper reflector, spacer layer, active layer, and spacer layer are arranged to reach the lower reflector. It is formed by etching by a dry etching method.

When the mesa shape is formed, the end face of the AlAs selective oxide layer is exposed. Therefore, the AlAs selective oxide layer is heat-treated in water vapor to change the AlAs to an Al _x As _y insulator, and the element drive current path is centered. A current confinement structure (oxidation aperture) is formed that limits only the unoxidized AlAs region.

  Thereafter, a p-side electrode is formed at a location excluding the light emitting portion (metal aperture) at the top of the mesa, and an n-side electrode is formed on the back surface of the substrate to fabricate a surface emitting laser element.

  In Non-Patent Document 1, 3.4 mW, which is a single mode maximum output in the 780 nm band, is obtained by optimizing the oxidation aperture and the metal aperture.

  However, an output of 7 mW has been reported in the 850 nm band and the 980 nm band, and the surface emitting laser element in the 780 nm band is inferior in terms of output. One way to increase the light output is to take measures to reduce the temperature rise of the light emitting section.

  As a method for suppressing the temperature rise of the light emitting portion, a configuration has been proposed in which a thermal resistance is reduced in a surface emitting laser element having an oscillation wavelength of 850 nm (Patent Document 1). And this structure consists of the structure which used AlAs whose heat conductivity is higher than AlGaAs for most of the low refractive index layers arrange | positioned under the lower reflective mirror.

  Conventional AlGaAs is used for the low refractive index layer on the upper side of the lower reflecting mirror. The reason for this is that when the etching surface when forming the mesa shape reaches the reflecting mirror using the lower AlAs, when the AlAs selective oxidation layer, which is a subsequent process of the etching, is oxidized, the exposed reflecting mirror This is to avoid this because AlAs is also oxidized and the element is insulated or increased in resistance.

That is, by providing AlGaAs with an oxidation rate slower than that of AlAs on the upper side of the lower reflecting mirror, the etching surface is positioned in the AlGaAs on the upper side of the lower reflecting mirror.
IEEE PHOTONICS TECHNOLOGY LETTERS, VOL.11, NO.12, 1999, pp.1539-1541. JP 2002-164621 A

  However, in the surface emitting laser element having a short oscillation wavelength, the temperature rise of the light emitting part is not sufficiently suppressed.

  Accordingly, the present invention has been made to solve such a problem, and an object thereof is to provide a surface emitting laser element having high output and good temperature characteristics.

  Another object of the present invention is to provide a surface emitting laser array including a surface emitting laser element having high output and good temperature characteristics.

  Furthermore, another object of the present invention is to provide an image forming apparatus including a surface emitting laser element having a high output and good temperature characteristics, or a surface emitting laser array using the surface emitting laser element.

  Furthermore, another object of the present invention is to provide an optical pickup device including a surface emitting laser element having high output and good temperature characteristics, or a surface emitting laser array using the surface emitting laser element.

  Furthermore, another object of the present invention is to provide an optical transmission module including a surface emitting laser element having a high output and good temperature characteristics, or a surface emitting laser array using the surface emitting laser element.

  Furthermore, another object of the present invention is to provide an optical transceiver module including a surface emitting laser element having a high output and good temperature characteristics, or a surface emitting laser array using the surface emitting laser element.

  Furthermore, another object of the present invention is to provide an optical communication system including a surface emitting laser element having high output and good temperature characteristics or a surface emitting laser array using the surface emitting laser element.

According to this invention, the surface emitting laser element includes the resonator and the first and second reflective layers. The resonator includes an active layer. The first reflective layer is composed of a semiconductor distributed Bragg reflector and is disposed on one side of the resonator. The second reflective layer is composed of a semiconductor distributed Bragg reflector and is disposed on the other side of the resonator. The at least one reflective layer of the first and second reflective layers includes a plurality of first semiconductor layers each made of Al _x Ga _1-x As (0 <x ≦ 1) having a first refractive index. And a plurality of second semiconductor layers made of Ga _y In _1-y P (0 <y <1) each having a second refractive index higher than the first refractive index. Consists of.

  Preferably, of the first and second reflective layers, the second reflective layer has a structure in which a plurality of first semiconductor layers and a plurality of second semiconductor layers are alternately stacked.

  Preferably, the surface emitting laser element further includes a substrate in contact with the heat sink. The second reflective layer is provided closer to the substrate than the active layer.

  Preferably, the wavelength of the oscillation light in the active layer is in the range of 680 nm to 830 nm.

  Preferably, the conductivity type of each of the first and second semiconductor layers is n-type.

  Preferably, the plurality of first semiconductor layers includes a plurality of first semiconductor films and a plurality of second semiconductor films. Each of the plurality of first semiconductor films is made of AlAs. Each of the plurality of second semiconductor films has an oxidation rate that is slower than the oxidation rate of AlAs. The plurality of second semiconductor films are disposed closer to the resonator than the plurality of first semiconductor films.

Preferably, each of the plurality of second semiconductor films is made of Al _z Ga _1-z As (0 <z <1).

  According to the invention, the surface emitting laser array includes a substrate and a plurality of surface emitting laser elements. The plurality of surface emitting laser elements are disposed on the substrate. Each of the plurality of surface emitting laser elements includes the surface emitting laser element according to any one of claims 1 to 7.

  Furthermore, according to the present invention, an image forming apparatus includes the writing light source including the surface emitting laser element according to any one of claims 1 to 7 or the surface emitting laser array according to claim 7. .

  Furthermore, according to the present invention, an optical pickup device includes a light source comprising the surface emitting laser element according to any one of claims 1 to 7 or the surface emitting laser array according to claim 8.

  Furthermore, according to this invention, an optical transmission module is provided with the light source which consists of a surface emitting laser element of any one of Claims 1-7, or the surface emitting laser array of Claim 8.

  Furthermore, according to this invention, an optical transceiver module is provided with the light source which consists of the surface emitting laser element of any one of Claim 1-7, or the surface emitting laser array of Claim 8.

  Furthermore, according to this invention, the optical communication system includes a light source including the surface-emitting laser element according to any one of claims 1 to 7 or the surface-emitting laser array according to claim 8.

The surface-emitting laser device according to the present invention includes a reflective layer using Ga _y In _1-y P (0 <y <1) as the high refractive index layer of the semiconductor distributed Bragg reflector. The thermal resistivity of the reflective layer becomes smaller than when Al _0.3 Ga _0.7 As or Al _0.5 Ga _0.5 As is used for the refractive index layer, and the temperature rise of the active layer is suppressed. That is, the heat dissipation characteristic of the heat generated in the active layer is improved.

  Therefore, according to the present invention, the output of the surface emitting laser element can be increased, and good temperature characteristics can be realized.

  In addition, since the surface emitting laser array according to the present invention includes the surface emitting laser element according to the present invention, the arrangement interval of the surface emitting laser elements can be reduced by reducing the arrangement interval.

  Further, since the image forming apparatus according to the present invention includes the surface emitting laser element or the surface emitting laser array according to the present invention as a light source, the number of surface emitting laser elements can be increased and writing can be performed on the photosensitive member. That is, it is possible to write on the photoconductor with a high dot density.

  Furthermore, since the optical pickup device according to the present invention includes the surface emitting laser element or the surface emitting laser array according to the present invention as a light source, recording and / or reproduction can be performed on an optical disc with a plurality of laser beams.

  Furthermore, since the optical transmission module according to the present invention includes the surface emitting laser element or the surface emitting laser array according to the present invention as a light source, signals can be transmitted by a plurality of laser beams. That is, the signal transmission speed can be increased.

  Furthermore, since the optical transceiver module according to the present invention includes the surface emitting laser element or the surface emitting laser array according to the present invention as a light source, signals can be transmitted by a plurality of laser beams. That is, the signal transmission speed can be increased.

  Furthermore, since the optical communication system according to the present invention includes the surface emitting laser element or the surface emitting laser array according to the present invention as a light source, the entire system can be speeded up.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a schematic sectional view of a surface emitting laser element according to Embodiment 1 of the present invention. Referring to FIG. 1, a surface emitting laser element 100 according to Embodiment 1 of the present invention includes a substrate 101, reflection layers 102 and 104, a resonator 103, a selective oxidation layer 105, a contact layer 106, SiO 2 _Two layers 107, an insulating resin 108, a p-side electrode 109, and an n-side electrode 110 are provided. The surface emitting laser element 100 is a 780 nm band surface emitting laser element.

  The resonator 103 includes a resonator spacer layer 1031, an active layer 1032, and a resonator spacer layer 1033.

The substrate 101 is made of (100) n-type gallium arsenide (n-GaAs) whose plane orientation is inclined at an inclination angle of 15 degrees in the (111) A plane direction. The reflective layer 102 has an n-Al _0.9 Ga _0.1 As / n-Ga _0.5 In _0.5 P pair as one period, and 40.5 periods of [n-Al _0.9 Ga _0.1 As / n-Ga _0.5 In _0.5 P], which is formed on one main surface of the substrate 101. The film thickness of each of n-Al _0.9 Ga _0.1 As and n-Ga _0.5 In _0.5 P is λ / 4 when the oscillation wavelength of the surface-emitting laser element 100 is λ. is there.

The resonator spacer layer 1031 has a structure in which non-doped (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P and non-doped Ga _0.5 In _0.5 P are sequentially stacked. Formed on top. The active layer 1032 has a quantum well structure with a compressive strain composition, and is formed on the resonator spacer layer 1031.

The resonator spacer layer 1033 has a structure in which non-doped Ga _0.5 In _0.5 P and non-doped (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P are sequentially stacked. The active layer 1032 Formed on top. The reflective layer 104 has 25 periods of [p-Al _0.9 Ga _0.1 As when a pair of p-Al _0.9 Ga _0.1 As / Al _0.3 Ga _0.7 As is taken as one period. / Al _0.3 Ga _0.7 As] and formed on the resonator spacer layer 1033. _Each of the thickness of the _p-Al 0.9 _{Ga 0.1} As and _Al 0.3 _{Ga 0.7} As is lambda / 4.

  The selective oxidation layer 105 is made of p-AlAs and is provided in the reflection layer 104. The selective oxidation layer 105 includes a non-oxidized region 105a and an oxidized region 105b, and has a thickness of 20 nm.

The contact layer 106 is made of p-GaAs and is formed on the reflective layer 104. The SiO ₂ layer 107 includes one main surface of a part of the reflective layer 102 and end surfaces of the resonator spacer layer 1031, the active layer 1032, the resonator spacer layer 1033, the reflective layer 104, the selective oxidation layer 105, and the contact layer 106. It is formed to cover.

The insulating resin 108 is formed in contact with the SiO ₂ layer 107. The p-side electrode 109 is formed on part of the contact layer 106 and the insulating resin 108. The n-side electrode 110 is formed on the back surface of the base plate 101.

  In the surface emitting laser element 100, the substrate 101 is connected to the heat sink 111 via the n-side electrode 110.

  Each of the reflection layers 102 and 104 constitutes a semiconductor distributed Bragg reflector that reflects the oscillation light oscillated in the active layer 1032 by Bragg multiple reflection and confines it in the active layer 1032.

FIG. 2 is a cross-sectional view of a part of the resonator 103 shown in FIG. Referring to FIG. 2, resonator spacer layer 1031 includes spacer layers 1031A and 1031B. The spacer layer 1031A is made of non-doped (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P, and the spacer layer 1031B is made of non-doped Ga _0.5 In _0.5 P.

The active layer 1032 includes well layers 1032A, 1032C, and 1032E, and barrier layers 1032B and 1032D. Each of the well layers 1032A, 1032C, and 1032E is made of GaINPAs, and each of the barrier layers 1032B and 1032D is made of Ga _0.5 In _0.5 P. As described above, the active layer 1032 includes three well layers and two barrier layers.

The resonator spacer layer 1033 includes spacer layers 1033A and 1033B. The spacer layer 1033A is made of non-doped Ga _0.5 In _0.5 P, and the spacer layer 1033B is made of non-doped (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P.

FIG. 3 is a schematic cross-sectional view showing the configuration of one reflective layer 102 shown in FIG. Referring to FIG. 3, the reflective layer 102 has a structure in which low refractive index layers 1021 and high refractive index layers 1022 are alternately stacked. The low refractive index layer 1021 is made of n-Al _0.9 Ga _0.1 As, and the high refractive index layer 1022 is made of n-Ga _0.5 In _0.5 P. The low refractive index layers 1021 and the high refractive index layers 1022 are alternately stacked for 40.5 periods. In this case, in FIG. 3, the lowermost low refractive index layer 1021 is in contact with the substrate 101, and the uppermost low refractive index layer 1021 is in contact with the resonator spacer layer 1031 of the resonator 103.

FIG. 4 is a schematic cross-sectional view showing the configuration of the other reflective layer 104 shown in FIG. Referring to FIG. 4, the reflective layer 104 includes a low refractive index layer 1041, a high refractive index layer 1042, and a composition gradient layer 1043. The low refractive index layer 1041 is made of p-Al _0.9 Ga _0.1 As, the high refractive index layer 1042 is made of p-Al _0.3 Ga _0.7 As, and the composition gradient layer 1043 has a low refractive index. It is made of AlGaAs whose composition is changed from one composition of the refractive index layer 1041 and the high refractive index layer 1042 to the other composition.

  The composition gradient layer 1043 is provided in order to reduce electrical resistance between the low refractive index layer 1041 and the high refractive index layer 1042.

  The low refractive index layer 1041 has a film thickness of d1, the high refractive index layer 1042 has a film thickness of d2, and the composition gradient layer 1043 has a film thickness of d3.

  In the case of a reflective layer having a steep interface that does not include the composition gradient layer 1043, the film thicknesses of the low refractive index layer and the high refractive index layer constituting the reflective layer are set so as to satisfy the Bragg multiple reflection phase condition. Λ / 4n (n is the refractive index of each semiconductor layer) with respect to the laser oscillation wavelength (λ = 780 nm).

  The film thickness of λ / 4n is such that the amount of phase change of oscillation light in each semiconductor layer is π / 2. In the case of including the composition gradient layer 1043 as in the surface emitting laser element 100, the thickness including each semiconductor layer and the composition gradient layer 1043 is set so as to satisfy the Bragg multiple reflection condition.

  The film thickness d3 is set to 20 nm, for example, and the film thicknesses d1 and d2 are set so that d1 + d3 and d2 + d3 satisfy the Bragg multiple reflection condition. That is, each of d1 + d3 and d2 + d3 is set so that the phase change amount of the oscillation light in the reflective layer 102 is π / 2.

FIG. 5 is a diagram showing the relationship between the thermal resistivity and the Al molar amount x in Al _x Ga _1-x As or (Al _x Ga _1-x ) _0.5 In _0.5 P. 6 is a diagram showing the energy _levels, the relationship between the Al _{x Ga 1-x} As or _{(Al x Ga 1-x)} 0.5 In 0.5 Al molar amount x of P.

In FIG. 5, the vertical axis represents thermal resistivity, and the horizontal axis represents Al _x Ga _1-x As (0 ≦ x ≦ 1) or (Al _x Ga _1-x ) _0.5 In _0.5 P ( The Al molar amount x in 0 ≦ x ≦ 1) is represented. The curve k1 shows the relationship between the Al molar amount x in (Al _x Ga _1-x ) _0.5 In _0.5 P lattice matched with GaAs and the thermal resistivity, and the curve k2 shows the Al _x Ga. The relationship between Al molar amount x in _1-x As and thermal resistivity is shown.

In FIG. 6, the vertical axis represents the energy level, and the horizontal axis represents the Al molar amount x in Al _x Ga _1-x As or (Al _x Ga _1-x ) _0.5 In _0.5 P. . A curve k3 _{is, (Al x Ga 1-x} ) and 0.5 _{an In 0.5} P in the Al molar content _{x, (Al x Ga 1-} x) 0.5 In 0.5 P of energy of the conduction band It shows the relationship between the level curve k4 _shows the Al molar amount x of Al _{x Ga 1-x as,} the relationship between the energy level of the conduction band of Al _{x Ga 1-x} as. Curve k5 _shows the relationship between the Al molar amount x of Al _{x Ga 1-x As,} and Al _{x Ga 1-x} As of the valence band energy level, the curve k6 _is (Al x _{Ga 1-} shows the Al molar amount x of _{x) 0.5} in _{0.5 P,} the relationship between the _{(Al x Ga 1-x)} 0.5 in 0.5 P of the valence band energy level.

_{(Al x Ga 1-x)} 0.5 In 0.5 P thermal resistivity is increased with increasing Al molar amount x. Ga _0.5 In _0.5 P having an Al molar amount x of “0” is the smallest heat among (Al _x Ga _1-x ) _0.5 In _0.5 P lattice-matched to GaAs. It has a resistivity (curve k1).

On the other hand, the thermal resistivity of Al _x Ga _1-x As is the highest when the Al molar amount x is 0.5, and decreases when the Al molar amount x increases or decreases from 0.5. . AlAs having an Al molar amount x of “1.0” and GaAs having an Al molar amount x of “0” have the lowest thermal resistivity. The thermal resistivity of Al _0.5 Ga _0.5 As is about 9 times that of AlAs or GaAs. (See curve k2).

The high refractive index layer in the reflection layer of the conventional surface emitting laser element is made of Al _0.3 Ga _0.7 As when the oscillation wavelength is in the 780 nm band, and Al _0.5 Ga when the oscillation wavelength is red. _It consists of _0.5 As (patent document 1).

As described above, the reflective layer 102 of the surface emitting laser element 100 includes the high refractive index layer 1022 made of Ga _0.5 In _0.5 P having the smallest thermal resistivity among AlGaInP lattice-matched to GaAs. The thermal resistivity of Ga _0.5 In _0.5 P is 6.36 Kcm / W, and Al _0.3 Ga _0.7 As and Al ₀ that are often used in conventional surface emitting laser elements. _.5 Ga _0.5 As thermal resistance of 8.57 [Kcm / W], lower than 9.19 [Kcm / W]. Thus, Ga _0.5 In _0.5 P has a thermal resistivity lower than that of Al _0.3 Ga _0.7 As and Al _0.5 Ga _0.5 As, and the substrate 101 Lattice-matched to GaAs, which is the material of

When the reflective layer 102 is formed by alternately stacking Al _0.9 Ga _0.1 As and Ga _0.5 In _0.5 P, the conduction band of Al _0.9 Ga _0.1 As and Ga _0.5 The energy difference from the conduction band of In _0.5 P corresponds to the energy difference between the point A on the curve k3 and the point B on the curve k4, and is 117 meV. On the other hand, when the reflective layer 102 is formed by alternately stacking Al _0.9 Ga _0.1 As and Ga _0.5 In _0.5 P, a valence band of Al _0.9 Ga _0.1 As and Ga The energy difference from the valence band of _0.5 In _0.5 P corresponds to the energy difference between the point C on the curve k5 and the point D on the curve k6, and is almost “0” eV. Therefore, unlike the reflective layer 104, the reflective layer 102 hardly increases in resistance value even if the composition gradient layer 1043 is not provided.

As described above, in the surface emitting laser element 100, the high refractive index layer 1022 of the reflective layer 102 is made of Ga _0.5 In _0.5 P having the smallest thermal resistivity. The reflective layer 102 is disposed on the substrate 101 side.

  As a result, even if laser light oscillates in the active layer 1032 of the surface emitting laser element 100 and heat is generated in the resonator 103, the generated heat is generated by the substrate 101 using the reflective layer 102 having a low thermal resistivity as a heat dissipation route. And radiated from the substrate 101 to the heat sink 111.

  Therefore, the temperature rise of the active layer 1032 can be suppressed, and high output and high performance characteristics can be obtained.

  7, 8, and 9 are first to third process diagrams showing a method for manufacturing the surface-emitting laser element 100 shown in FIG. 1, respectively. Referring to FIG. 7, when a series of operations is started, the reflective layer 102, the resonator spacer layer 1031, the active layer 1032, the resonance layer 1032 are formed using metal organic chemical vapor deposition (MOCVD). A container spacer layer 1033, a reflective layer 104, a selective oxidation layer 105, and a contact layer 106 are sequentially stacked on the substrate 101 (see step (a) in FIG. 7).

In this case, n-Al _0.9 Ga _0.1 As for the reflective layer 102 is formed using trimethylaluminum (TMA), trimethylgallium (TMG), arsine (AsH ₃ ), and hydrogen selenide (H ₂ Se) as raw materials. Then, n-Ga _0.5 In _0.5 P of the reflective layer 102 is formed using trimethyl gallium (TMG), trimethyl indium (TMI), phosphine (PH ₃ ), and hydrogen selenide (H ₂ Se) as raw materials.

In addition, (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P of the resonator spacer layer 1031 is changed to trimethylaluminum (TMA), trimethylgallium (TMG), trimethylindium (TMI), and phosphine (PH ₃ ). As a raw material, Ga _0.5 In _0.5 P is formed using trimethyl gallium (TMG), trimethyl indium (TMI), phosphine (PH ₃ ), and hydrogen selenide (H ₂ Se) as raw materials.

Further, GaInPAs of the quantum well active layer is formed using trimethylgallium (TMG), trimethylindium (TMI), phosphine (PH ₃ ), and arsine (AsH ₃ ) as raw materials, and Ga _0.5 In _0.5 P of the barrier layer is formed. From trimethylgallium (TMG), trimethylindium (TMI) and phosphine (PH ₃ ).

Further, Ga _0.5 In _0.5 P of the resonator spacer layer 1033 is formed using trimethyl gallium (TMG), trimethyl indium (TMI), phosphine (PH ₃ ), and hydrogen selenide (H ₂ Se) as raw materials, Cavity spacer 1033 (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P is made from trimethylaluminum (TMA), trimethylgallium (TMG), trimethylindium (TMI) and phosphine (PH ₃ ) as raw materials. Form.

_{Further, p-Al 0.9 Ga 0.1 As} / p-Al 0.3 Ga 0.7 As trimethylaluminum reflective layer 104 (TMA), trimethyl gallium (TMG), arsine (AsH ₃₎ and tetrabromide Carbonized carbon (CBr ₄ ) is used as a raw material.

Further, p-AlAs of the selective oxidation layer 105 is formed using trimethylaluminum (TMA), arsine (AsH ₃ ), and carbon tetrabromide (CBr ₄ ) as raw materials, and p-GaAs of the contact layer 106 is formed of trimethylgallium (TMG). , Arsine (AsH ₃ ) and carbon tetrabromide (CBr ₄ ).

  Thereafter, a resist is applied on the contact layer 106, and a resist pattern 120 is formed on the contact layer 106 using a photoengraving technique (see step (b) in FIG. 7).

  When the resist pattern 120 is formed, peripheral portions of the resonator spacer layer 1031, the active layer 1032, the resonator spacer layer 1033, the reflective layer 104, the selective oxidation layer 105, and the contact layer 106 are formed using the formed resist pattern 120 as a mask. Is removed by dry etching, and the resist pattern 120 is further removed (see step (c) in FIG. 7).

  Next, referring to FIG. 8, after the step (c) shown in FIG. 7, the sample is heated to 425 ° C. in an atmosphere in which water heated to 85 ° C. is bubbled with nitrogen gas, and the selective oxidation layer 105. Is oxidized from the outer peripheral portion toward the central portion to form a non-oxidized region 105a and an oxidized region 105b in the selective oxidation layer 105 (see step (d) in FIG. 8). In this case, the non-oxidized region 105a is a square having a side of 4 μm.

Thereafter, a SiO ₂ layer 107 is formed on the entire surface of the sample by using a chemical vapor deposition (CVD) method, and a region serving as a light emitting portion and a surrounding SiO ₂ layer using a photoengraving technique. 107 is removed (see step (e) in FIG. 8).

  Next, the insulating resin 108 is applied to the entire sample by spin coating, and the insulating resin 108 on the region to be the light emitting portion is removed (see step (f) in FIG. 8).

  Referring to FIG. 9, after forming insulating resin 108, a resist pattern having a predetermined size is formed on a region to be a light emitting portion, and a p-side electrode material is formed on the entire surface of the sample by vapor deposition. The p-side electrode 109 is formed by removing the p-side electrode material on the pattern by lift-off (see step (g) in FIG. 9). Then, the back surface of the substrate 101 is polished, the n-side electrode 110 is formed on the back surface of the substrate 101, and further annealed to establish ohmic conduction between the p-side electrode 109 and the n-side electrode 110 (step (h) in FIG. 9). reference). Thus, the surface emitting laser element 100 is manufactured.

As described above, in the surface emitting laser element 100, the n-type reflective layer 102 is formed using Ga _0.5 In _0.5 P, and the heat dissipation characteristics of the heat generated in the active layer 1032 are improved. When the n-type reflective layer 102 is formed using Ga _0.5 In _0.5 P, the energy difference between the conduction bands of the low refractive index layer 1021 and the high refractive index layer 1022 in the reflective layer 102 is about 117 meV. Therefore, electrons in the conduction band easily move in the thickness direction of the reflective layer 102, and the resistance of the reflective layer 102 does not increase. Therefore, in the present invention, preferably, the n-type reflective layer 102 is formed using Ga _0.5 In _0.5 P.

  In the above description, the substrate 101 is made of (100) n-GaAs whose plane orientation is inclined at an inclination angle of 15 degrees in the (111) A plane direction. However, in the present invention, the substrate 101 is not limited to this. The surface orientation may be made of (100) n-GaAs inclined in the range of an inclination angle of 5 degrees to 25 degrees in the (111) A plane direction.

In the above description, the high refractive index layer 1022 of the reflective layer 102 has been described as being made of n-Ga _0.5 In _0.5 P. However, the present invention is not limited to this, and the high refractive index layer 1022 has a high refractive index. rate layer 1022 _is generally it is sufficient that the _{n-Ga y in 1-y} P (0 <y <1).

The thermal resistance of GaInP is equivalent to AlGaAs-based Al _0.15 Ga _0.85 As, and it is necessary to use a material having a higher Al composition than Al _0.15 Ga _0.85 As for the high refractive index layer. In the light emitting laser element, if it is replaced with GaInP, the heat dissipation is improved, the temperature rise of the active layer 1032 is suppressed, and there is an effect of increasing the output. By using n-Ga _0.5 In _0.5 P for the high refractive index layer 1022 of the reflective layer 102, the temperature rise in the active layer 1032 can be suppressed and the output of the surface emitting laser element 100 can be increased. Therefore, it is necessary that n-Ga _0.5 In _0.5 P hardly absorbs the laser light oscillated in the active layer 1032.

A wavelength corresponding to energy that is 100 meV smaller than the band gap of n-Ga _0.5 In _0.5 P hardly becomes a standard because the laser light oscillated in the active layer 1032 is hardly absorbed. Therefore, the wavelength at which n-Ga _0.5 In _0.5 P (1.91 eV) can be used is longer than 680 nm, and n-Al _0.15 Ga _0.85 As (1.59 eV). The wavelength that can be used is shorter than 830 nm.

As a result, the oscillation wavelength of the surface emitting laser element 100 that can increase the output by using n-Ga _0.5 In _0.5 P for the high refractive index layer 1022 of the reflective layer 102 is in the range of 680 nm to 830 nm. .

Furthermore, in the above description, it has been described that the low refractive index layer 1021 of the reflective layer 102 is made of n-Al _0.9 Ga _0.1 As. However, in the present invention, the low refractive index layer 1021 is not limited to this. , N-Al _x Ga _1-x As (0 <x ≦ 1). In the reflective layer 102, the thermal resistivity is n-Al instead of n-Al _0.3 Ga _0.7 As or n-Al _0.5 Ga _0.5 As conventionally used for the high refractive index layer. _Since the high refractive index layer 1022 is formed using n-Ga _0.5 In _0.5 P smaller than _0.3 Ga _0.7 As or n-Al _0.5 Ga _0.5 As, the low refractive index This is because even if the rate layer 1021 is made of n-Al _x Ga _1-x As (0 <x ≦ 1), the reflective layer 102 has a low thermal resistivity and functions as a main heat dissipation route.

Furthermore, in the above description, Ga _0.5 In _0.5 P has been described as being used for the n-type reflective layer 102 disposed on the substrate 101 side. However, the present invention is not limited to this, and Ga _{0 .5} In _0.5 P may be used for the high-refractive index layer 1042 of the p-type reflective layer 104, and may be used for the high-refractive index layers 1022 and 1042 of both the reflective layers 102 and 104. Generally, it may be used for the high refractive index layer of at least one of the reflective layers 102 and 104. When Ga _0.5 In _0.5 P is used for the high refractive index layer 1042, the reflective layer 104 does not include the composition gradient layer 1043.

  Furthermore, in the above description, it has been described that the MOCVD method is used as a method for forming each semiconductor layer constituting the surface emitting laser element 100. However, the present invention is not limited to this, and a molecular beam crystal growth method (MBE: Molecular Beam) is used. Other crystal growth methods such as Epitaxy) may be used.

  The reflective layer 104 constitutes a “first reflective layer”, and the reflective layer 102 constitutes a “second reflective layer”.

  The plurality of low-refractive index layers 1021 or the plurality of low-refractive index layers 1041 constitute “a plurality of first semiconductor layers”, and the plurality of high-refractive index layers 1022 are “a plurality of second semiconductor layers”. Configure.

[Embodiment 2]
FIG. 10 is a schematic cross-sectional view of the surface emitting laser element according to the second embodiment. Referring to FIG. 10, surface emitting laser element 100A according to the second embodiment is obtained by replacing reflective layer 102 of surface emitting laser element 100 shown in FIG. 1 with reflecting layer 102A, and the others are surface emitting laser elements. The same as 100.

  The reflective layer 102A includes the reflective layers 112 and 113. The reflective layer 112 is formed on the substrate 101, and the reflective layer 113 is formed on the reflective layer 112.

  FIG. 11 is a cross-sectional view showing the configuration of the reflective layer 102A shown in FIG. Referring to FIG. 11, the reflective layer 112 has a structure in which low refractive index layers 1121 and high refractive index layers 1122 are alternately stacked. The low refractive index layer 1121 and the high refractive index layer 1122 are stacked for 30.5 periods when the pair of the low refractive index layer 1121 and the high refractive index layer 1122 is one period.

The low refractive index layer 1121 is made of n-AlAs, and the high refractive index layer 1122 is made of n-Ga _0.5 In _0.5 P. Each of the low refractive index layer 1121 and the high refractive index layer 1122 has a film thickness of λ / 4 of the oscillation wavelength (λ = 780 nm) of the surface emitting laser element 100A.

  The reflective layer 113 has a structure in which low refractive index layers 1131 and high refractive index layers 1132 are alternately stacked. The low refractive index layer 1131 and the high refractive index layer 1132 are stacked for 10 periods when the pair of the low refractive index layer 1131 and the high refractive index layer 1132 is defined as one period.

The low refractive index layer 1131 is made of n-Al _0.9 Ga _0.1 As, and the high refractive index layer 1122 is made of n-Ga _0.5 In _0.5 P. Each of the low refractive index layer 1131 and the high refractive index layer 1132 has a film thickness of λ / 4 of the oscillation wavelength (λ = 780 nm) of the surface emitting laser element 100A.

Since AlAs has the smallest thermal resistivity among Al _x Ga _1-x As lattice-matched to GaAs (see curve k2 in FIG. 5), n-AlAs and n-Ga _0.5 In _0.5 P The thermal resistance of the reflective layer 112 can be reduced by forming the reflective layer 112 using the above.

The reflective layer 113 is provided to position the etching surface in the reflective layer 113 when a mesa shape is produced. Since the oxidation rate of n-Al _0.9 Ga _0.1 As is slower than the oxidation rate of n-AlAs, by forming the reflective layer 113 using n-Al _0.9 Ga _0.1 As, Since the etching surface only needs to be stopped in the reflective layer 113, the reflective layer 113 can be provided with a margin of the etching depth when forming the mesa.

As described above, the surface emitting laser element 100A includes the reflective layer 112 formed using AlAs having the lowest thermal resistivity among Al _x Ga _1-x As lattice-matched to GaAs, and is disposed on the substrate 101 side. The reflective layer 113 formed using n-Al _0.9 Ga _0.1 As, whose speed is slower than that of AlAs, is arranged on the active layer 1032 side of the reflective layer 112.

Then, the reflective layer 113 is _generally, may be composed of a periodic structure of _{[n-Al x Ga 1-} x As / n-Ga 0.5 In 0.5 P].

  The surface emitting laser element 100A is manufactured according to the steps (a) to (h) shown in FIGS.

In the above description, the oxidation rate using _Al x _{Ga 1-x} As as the slower semiconductor than AlAs, the present invention is not limited to this, the oxidation rate is if slower semiconductor than AlAs, _Al x Ga A semiconductor other than _1-x As may be used.

  The plurality of low refractive index layers 1121 and the plurality of low refractive index layers 1131 constitute “a plurality of first semiconductor layers”, and the plurality of high refractive index layers 1122 and the plurality of high refractive index layers 1132 include “ Constitutes a "second semiconductor layer".

The plurality of low-refractive index layers 1121 each made of n-AlAs constitute “a plurality of first semiconductor films”, and the low-refractive index layers 1131 each made of n-Al _0.9 Ga _0.1 As are , “A plurality of second semiconductor films” are formed.

  Others are the same as in the first embodiment.

[Application example]
FIG. 12 is a plan view of a surface emitting laser array using the surface emitting laser element 100 shown in FIG. Referring to FIG. 12, surface emitting laser array 200 has a structure in which 36 surface emitting laser elements 202 are arranged on base 201 at a predetermined interval. The surface emitting laser element 202 includes any of the surface emitting laser elements 100 and 100A described above.

  Since the surface emitting laser elements 100 and 100A are of a surface emitting type, the array is easy and the positional accuracy of the elements is high. The surface emitting laser elements 100 and 100A have a structure with improved heat dissipation characteristics as described above. Therefore, the surface emitting laser array 200 can be densified by reducing the interval between elements as compared with the conventional surface emitting laser array. As a result, the number of chips can be increased and the cost can be reduced.

  In addition, by integrating a large number of surface emitting laser elements 100 and 100A capable of high output operation on the same substrate, when applied to a writing optical system, simultaneously writing with multi-beams is facilitated, and the writing speed is greatly improved. Even if the writing dot density increases, printing can be performed without reducing the printing speed. When the writing dot density is the same, the printing speed can be increased. Furthermore, when applied to communication, data transmission by multiple beams is possible at the same time, so high-speed communication is possible. Furthermore, the surface emitting laser elements 100 and 100A operate with low power consumption, and particularly when used by being incorporated in a device, temperature rise can be reduced.

  FIG. 13 is a schematic diagram of the image forming apparatus. Referring to FIG. 13, the image forming apparatus 300 includes a surface emitting laser array 301, lenses 302 and 304, a polygon mirror 303, and a photoconductor 305.

  The surface emitting laser array 301 emits a plurality of beams. The lens 302 guides a plurality of beams emitted from the surface emitting laser array 301 to the polygon mirror 303.

  The polygon mirror 303 rotates clockwise at a predetermined speed, scans a plurality of beams received from the lens 302 in the main scanning direction and the sub-scanning direction, and guides them to the lens 304. The lens 304 guides a plurality of beams scanned by the polygon mirror 303 to the photoconductor 305.

  As described above, the image forming apparatus 300 uses the same optical system including the lenses 302 and 304 and the polygon mirror 303 for the plurality of beams from the surface emitting laser array 301, rotates the polygon mirror 303 at a high speed, and sets the dot position. Light is condensed on the photoconductor 305 as the surface to be scanned as a plurality of light spots separated in the sub-scanning direction by adjusting the lighting timing.

  FIG. 14 is a plan view of the surface emitting laser array 301 shown in FIG. Referring to FIG. 14, a surface emitting laser array 301 has a structure in which m × n surface emitting laser elements 3011 are arranged in a substantially rhombus. More specifically, the surface emitting laser array 301 includes 40 surface emitting laser elements 3011 arranged in four columns in the vertical direction and ten columns in the horizontal direction. The surface emitting laser element 3011 is composed of either the surface emitting laser element 100 or 100A.

  If the distance between two adjacent surface-emitting laser elements 3011 in the vertical direction is d, the recording density is determined by d / n. Accordingly, the surface emitting laser array 301 determines the interval d and the number n of arrangement in the main scanning direction in consideration of the recording density.

  In FIG. 14, 40 surface-emitting laser elements 3011 are shifted by 2.4 μm in the sub-scanning direction as they go in the main scanning direction at intervals of 24 μm in the sub-scanning direction, at intervals of 30 μm in the main scanning direction. Arranged.

  Then, by adjusting the lighting timing of the 40 surface emitting laser elements 3011, 40 dots can be written on the photoconductor 305 at regular intervals in the sub-scanning direction.

  When the magnification of the optical system is the same, writing can be performed with higher density as the distance d in the sub-scanning direction of the surface emitting laser array 301 is smaller. Since the surface emitting laser element 3011 is composed of any one of the surface emitting laser elements 100 and 100A, in the surface emitting laser array 301, the arrangement density of the surface emitting laser elements 3011 can be increased. As a result, the image forming apparatus 300 can perform high-density writing.

  In addition, 40 dots can be written simultaneously, and high-speed printing is possible. Further, higher speed printing is possible by increasing the number of arrays.

  Further, since the surface emitting laser element 3011 has a higher output than the conventional surface emitting laser element, the printing speed can be increased compared with the conventional case where an array having the same number of elements is formed using the conventional surface emitting laser element. Can be faster.

  The surface emitting laser arrays 200 and 301 or the surface emitting laser elements 100 and 100A may be mounted on an optical pickup device. Accordingly, the surface emitting laser arrays 200 and 301 or the surface emitting laser elements 100 and 100A can be used as a light source for recording and / or reproducing on an optical disk. Further, since the surface emitting laser consumes about one digit less power than the edge emitting semiconductor laser, a handy type optical pickup system using the 780 nm surface emitting laser according to the present invention for a long-lasting power is provided. realizable.

  FIG. 15 is a schematic diagram of an optical transmission module. Referring to FIG. 15, the optical transmission module 400 includes a surface emitting laser array 401 and an optical fiber 402. The surface emitting laser array 401 has a structure in which a plurality of surface emitting laser elements 100 and 100A are arranged one-dimensionally. The optical fiber 402 is composed of a plurality of plastic optical fibers (POF). The plurality of plastic optical fibers are arranged corresponding to the plurality of surface emitting laser elements 100 and 100A of the surface emitting laser array 401.

  In the optical transmission module 400, the laser light emitted from the surface emitting laser elements 100 and 100A is transmitted to the corresponding plastic optical fiber. An acrylic plastic optical fiber has a bottom of absorption loss at 650 nm and a surface-emitting laser element having a wavelength of 650 nm has been studied. However, the high-temperature characteristic is poor and has not been put into practical use.

  Although an LED (Light Emitting Diode) is used as a light source, high-speed modulation is difficult, and a semiconductor laser is required to realize high-speed transmission exceeding 1 Gbps.

  The oscillation wavelengths of the surface emitting laser elements 100 and 100A described above are 780 nm, but the heat dissipation characteristics are improved, the output is high, and the high temperature characteristics are excellent. If it is a distance, transmission is possible.

  In the field of optical communication, parallel transmission using a laser array in which a plurality of semiconductor lasers are integrated has been attempted in order to transmit more data at the same time. As a result, high-speed parallel transmission is possible, and more data than before can be transmitted simultaneously.

  In the optical transmission module 400, the surface emitting laser elements 100 and 100A and the optical fiber are made to correspond one-to-one, but a plurality of surface emitting laser elements having different oscillation wavelengths are arranged in an array in one or two dimensions. Thus, the transmission speed can be further increased by wavelength multiplexing transmission.

  Furthermore, when an optical transmission module 400 combining a surface emitting laser array using the surface emitting laser elements 100 and 100A and an inexpensive POF is used in an optical communication system, a low-cost optical transmission module can be realized. The low-cost optical communication system used can be realized. Since the cost is extremely low, it is effective for short-distance data communication for home use, office room use, and in an apparatus.

  FIG. 16 is a schematic diagram of an optical transceiver module. Referring to FIG. 16, the optical transceiver module 500 includes a surface emitting laser element 501, an optical fiber 502, and a light receiving element 503.

  The surface-emitting laser element 501 is composed of any one of the surface-emitting laser elements 100 and 100 </ b> A, and radiates 780 nm laser light LB <b> 1 to the optical fiber 502. The optical fiber 502 is made of a plastic optical fiber. The optical fiber 502 receives the laser beam LB1 from the surface emitting laser element 501, transmits the received laser beam LB1 to a receiving module (not shown), and receives it from another transmitting module (not shown). The laser beam is transmitted and the laser beam LB2 is emitted to the light receiving element 503. The light receiving element 503 receives the laser beam LB2 from the optical fiber 502 and converts the received laser beam LB2 into an electrical signal.

  As described above, the transmission / reception module 500 emits the laser beam LB1 and transmits the laser beam LB1 through the optical fiber 502, and receives the laser beam LB2 from another transmission module and converts it into an electrical signal.

  Since the transmission / reception module 500 is manufactured using the surface emitting laser elements 100 and 100A and an inexpensive plastic optical fiber, a low-cost optical communication system can be realized. Further, since the diameter of the optical fiber 502 is large, coupling between the surface emitting laser element 501 and the optical fiber 502 is easy, and the mounting cost can be reduced. As a result, an extremely low cost optical transceiver module can be realized.

  Further, the surface emitting laser element 501 (= surface emitting laser element 100, 100A) has improved heat dissipation characteristics, high output and excellent high temperature characteristics, and can be used without cooling to high temperature, and A lower cost optical transceiver module can be realized.

  As an optical communication system using the above-described surface-emitting laser elements 100 and 100A, transmission between devices such as a LAN (Local Area Network) using an optical fiber, data transmission between boards in the device, In particular, it can be used for short-distance communication as an optical interconnection between LSIs and between elements in LSIs.

  In recent years, the processing performance of LSIs and the like has improved, but the transmission speed of the portion connecting them will be governed in the future. When the signal connection in the system is changed from the conventional electrical connection to the optical interconnection, for example, the optical transmission module 400 or the optical transmission / reception module 500 is connected between the boards of the computer system, between the LSIs in the board, and between the elements in the LSI. When used and connected, an ultrafast computer system is possible.

  In addition, when a plurality of computer systems or the like are connected using the optical transmission module 400 or the optical transmission / reception module 500, an ultrahigh-speed network system can be constructed. Particularly, the surface emitting laser is suitable for a parallel transmission type optical communication system because it can reduce power consumption by an order of magnitude compared to the edge emitting laser and can easily form a two-dimensional array.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  The present invention is applied to a surface emitting laser element having high output and good temperature characteristics. The present invention is also applied to a surface emitting laser array including a surface emitting laser element having high output and good temperature characteristics. Furthermore, the present invention is applied to an image forming apparatus including a surface emitting laser element having high output and good temperature characteristics, or a surface emitting laser array using the surface emitting laser element. Furthermore, the present invention is applied to an optical pickup device including a surface emitting laser element having high output and good temperature characteristics, or a surface emitting laser array using the surface emitting laser element. Furthermore, the present invention is applied to an optical transmission module including a surface emitting laser element having high output and good temperature characteristics, or a surface emitting laser array using the surface emitting laser element. Furthermore, the present invention is applied to an optical transmission / reception module including a surface emitting laser element having high output and good temperature characteristics, or a surface emitting laser array using the surface emitting laser element. Furthermore, the present invention is applied to an optical communication system including a surface emitting laser element having high output and good temperature characteristics, or a surface emitting laser array using the surface emitting laser element.

It is a schematic sectional drawing of the surface emitting laser element by Embodiment 1 of this invention. FIG. 2 is a cross-sectional view of a part of the resonator shown in FIG. 1. It is a schematic sectional drawing which shows the structure of one reflection layer shown in FIG. It is a schematic sectional drawing which shows the structure of the other reflection layer shown in FIG. And the thermal resistance _is a diagram showing the relationship between the Al _{x Ga 1-x} As or _{(Al x Ga 1-x)} 0.5 In 0.5 P in the Al molar content x. And energy level _is a diagram showing the relationship between the Al _{x Ga 1-x} As or _{(Al x Ga 1-x)} 0.5 In 0.5 P in the Al molar content x. FIG. 3 is a first process diagram showing a method for manufacturing the surface emitting laser element shown in FIG. 1. FIG. 6 is a second process diagram illustrating a method for manufacturing the surface emitting laser element illustrated in FIG. 1. FIG. 6 is a third process diagram illustrating a method for manufacturing the surface emitting laser element illustrated in FIG. 1. 6 is a schematic cross-sectional view of a surface emitting laser element according to a second embodiment. FIG. It is sectional drawing which shows the structure of the reflection layer shown in FIG. It is a top view of the surface emitting laser array using the surface emitting laser element shown in FIG. 1 is a schematic diagram of an image forming apparatus. It is a top view of the surface emitting laser array shown in FIG. It is the schematic of an optical transmission module. It is the schematic of an optical transmission / reception module.

Explanation of symbols

100, 100A, 202, 501, 3011 Surface emitting laser element, 101, 201 substrate, 102, 102A, 104, 112, 113 reflective layer, 103 resonator, 105 selective oxide layer, 105a non-oxidized region, 105b oxidized region, 106 Contact layer, 107 SiO ₂ layer, 108 insulating resin, 109 p-side electrode, 110 n-side electrode, 111 heat sink, 120 resist pattern, 200, 301, 401 surface emitting laser array, 300 image forming apparatus, 302, 304 lens, 303 Polygon mirror, 305 Photoconductor, 400 Optical transmission module, 402,502 Optical fiber, 500 Optical transmission / reception module, 503 Light receiving element, 1021, 1041, 1121, 1131 Low refractive index layer, 1022, 1042, 1122, 1132 High refractive index layer 10 1,1033 cavity spacer layer, 1031A, 103 IB, 1033A, 1033b spacer layer, 1032 an active layer, 1032A, 1032C, 1032E well layer, 1032B, 1032D barrier layer, 1043 composition gradient layer.

Claims (13)

A resonator including an active layer;
A first reflective layer comprising a semiconductor distributed Bragg reflector, disposed on one side of the resonator;
Comprising the semiconductor distributed Bragg reflector, and comprising a second reflective layer disposed on the other side of the resonator,
The at least one reflective layer of the first and second reflective layers includes a plurality of first semiconductor layers made of Al _x Ga _1-x As (0 <x ≦ 1) each having a first refractive index. A structure in which a plurality of second semiconductor layers made of Ga _y In _1-y P (0 <y <1) each having a second refractive index higher than the first refractive index are alternately stacked. A surface emitting laser element comprising:   The second reflective layer of the first and second reflective layers has a structure in which the plurality of first semiconductor layers and the plurality of second semiconductor layers are alternately stacked. 2. The surface emitting laser element according to 1. Further comprising a substrate in contact with the heat sink;
The surface emitting laser element according to claim 2, wherein the second reflective layer is provided closer to the substrate than the active layer.   4. The surface-emitting laser element according to claim 1, wherein the wavelength of the oscillation light in the active layer is in a range of 680 nm to 830 nm.   5. The surface-emitting laser element according to claim 1, wherein each of the first and second semiconductor layers has an n-type conductivity. 6. The plurality of first semiconductor layers include:
A plurality of first semiconductor films each made of AlAs;
Each consisting of a plurality of second semiconductor films having an oxidation rate slower than the oxidation rate of the AlAs,
6. The surface-emitting laser element according to claim 1, wherein the plurality of second semiconductor films are arranged closer to the resonator than the plurality of first semiconductor films. The surface emitting laser element according to claim 6, wherein each of the plurality of second semiconductor films is made of Al _z Ga _1-z As (0 <z <1). A substrate,
A plurality of surface emitting laser elements disposed on the substrate,
Each of these surface emitting laser elements is a surface emitting laser array which consists of a surface emitting laser element of any one of Claim 1-7.   An image forming apparatus comprising a writing light source comprising the surface emitting laser element according to claim 1 or the surface emitting laser array according to claim 7.   An optical pickup device comprising a light source comprising the surface-emitting laser element according to claim 1 or the surface-emitting laser array according to claim 8.   An optical transmission module comprising a light source comprising the surface emitting laser element according to any one of claims 1 to 7 or the surface emitting laser array according to claim 8.   An optical transceiver module comprising a light source comprising the surface emitting laser element according to any one of claims 1 to 7 or the surface emitting laser array according to claim 8.   An optical communication system comprising a light source comprising the surface emitting laser element according to any one of claims 1 to 7 or the surface emitting laser array according to claim 8.