JP3242192B2 - Semiconductor laser device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface-emitting wavelength-division multiplexing semiconductor laser device suitable for a light source for optical information processing or optical measurement and optical communication.

[0002]

2. Description of the Related Art In the prior art, in a surface emitting type semiconductor laser in which a vertical cavity is formed with respect to a semiconductor substrate,
It has been reported that the current injection type oscillation at room temperature in the short wavelength region of the 0.6 μm band and the long wavelength region of the 0.98 μm band. For example, well-known example 1) I II Photonics Technology Letters 1992, 4, 1195 (IEE
EPhoton.Technol.Lett., 4 (1992) 1195) and known example 2).
I II Journal Quantum Electronics 1991, 27, 1359 (IEEE J. Quantum Elect
ron., 27 (1991) 1359).

[0003]

In the above prior art, only a semiconductor laser light source having a single oscillation wavelength on a semiconductor substrate is described, but a multi-wavelength laser having a different oscillation wavelength in the same space on the same substrate. No description is given of a surface-emitting type semiconductor laser having a light source.

An object of the present invention is to provide a multi-wavelength laser light source in the same space by vertically stacking and integrating at least two or more sets of active layer structures having different oscillation wavelengths on the same semiconductor substrate. Another object of the present invention is to provide a multi-wavelength surface-emitting type semiconductor laser device having a vertical cavity structure with very small light absorption. For example, a group III-V semiconductor laser and a group II-VI semiconductor laser have a vertical structure, and an active layer, an optical waveguide layer and a light reflecting film structure are integrated in multiple stages on the same substrate so that light absorption does not become a problem. By specifying the direction in which the laser light is emitted, a white semiconductor laser element that takes out the three primary colors red, green and blue in the same space can be realized.

[0005]

Means for achieving the above object will be described below.

At least two or more sets of active layer structures having different oscillation wavelengths are vertically stacked on the same semiconductor substrate, and in order to take out a multi-wavelength laser light source in the same space, the emission direction of the laser light is first defined. When the forbidden band width of the semiconductor substrate is smaller than the forbidden band of each of the active layers laminated thereon, the laser light is extracted from the side opposite to the substrate to avoid light absorption. At this time, a light reflection film (DBR: Distributed Bragg Reflector) provided below the stacked active layer
The structure is set to have a high reflectance so that the laser light emitted from all the active layers is directed upward. On the other hand, when the forbidden band width of the semiconductor substrate is larger than the forbidden band of each active layer laminated thereon, the laser beam may be extracted from the substrate side, or may be extracted from the side opposite to the semiconductor substrate. . At this time, when a highly reflective film is provided below the stacked active layers, laser light is emitted from the upper side, and when the highly reflective film is provided above the active layer, laser light is emitted from the substrate side.

For the light reflecting film DBR structure set on the upper side or the lower side of the active layer, a combination of materials capable of having a very small light absorption and a large difference in refractive index is selected, and the forbidden band width of a specific active layer is selected. It is designed so that a high reflectance of at least 90% or more can be obtained in the region. On the other resonator surface, a high reflection film structure is formed by a dielectric film or a metal thin film on the semiconductor substrate side or on the uppermost portion of the laminated semiconductor. Thereby, a vertical resonator structure can be formed for all the active layers,
A surface-emitting type semiconductor laser device oscillating at multiple wavelengths can be obtained on the same substrate and in the same space.

[0008]

The above means will be described in order to achieve the object.

On the same semiconductor substrate, at least two sets of active layer structures having different laser oscillation wavelengths are vertically stacked by using a III-V group semiconductor or a II-VI group semiconductor material. For example, when a GaAs substrate is used as a semiconductor substrate, in order to extract a short-wavelength laser light source of three primary colors red, green and blue whose energy is larger than the band gap of the substrate into the same space, a laser beam is emitted from the side opposite to the substrate. A highly reflective film is provided so that it can be formed. Each active layer having the three primary colors of red, green, and blue oscillation wavelengths is laminated on a substrate in order of energy, and
A highly reflective film having a DBR structure is manufactured. Further, on the upper surface of one of the stacked semiconductors, a multilayer film serving as a resonator surface having a high reflectance over a very wide wavelength is formed by a dielectric or metal film. Thereby, a vertical resonator structure can be formed for each active layer. However, at this time, by making the reflectivity slightly lower than that of the DBR structure high reflection film provided under each active layer to give a difference, laser light sources having different oscillation wavelengths in the same space on the opposite side of the substrate are provided. Can be taken out.

The DBR structure highly reflective film provided below each active layer is formed of a III-V semiconductor or II-VI semiconductor material having a larger bandgap than each active layer, and has at least two different refractive indexes. A combination of layers or more is used to have a reflectance of 90% or more. For example, as shown in FIG. 4, a ZnSSe layer having a composition lattice-matched to a GaAs substrate and a ZnMgS
By combining the Se layer, the blue wavelength range 460
A high reflectance close to 100% can be obtained at about 470 nm. Here, the ZnSSe layer has a thickness of 26 nm,
The gSSe layer has a thickness of 43 nm and is provided for 30 periods. At this time, the green wavelength range around 530 nm or the red wavelength range 6
In the vicinity of 30 nm, since the reflectivity is reduced to about 30% or less, the ZnSSe layer and the ZnMgSSe
The reflection film formed by the layer is 100% only in the blue wavelength region.
It becomes a near high reflection film.

Next, as shown in FIG.
Green wavelength range 520 to 530 using the layer and the ZnMgSSe layer.
A high reflectance close to 100% in nm can be obtained. Here, the ZnSSe layer has a thickness of 34 nm, and the ZnMgSSe layer has a thickness of 55 nm, and is provided for 30 periods. At this time,
Near blue wavelength range 460nm or red wavelength range 630nm
In the vicinity, since the reflectivity is about 20% or less, the reflection film formed of the ZnSSe layer and the ZnMgSSe layer for the three primary colors of blue, green, and red has high reflection close to 100% only in the green wavelength region. It becomes a film.

Further, as shown in FIG. 6, a red wavelength region of 625 to 635 nm is formed by using an AlGaInP layer and an AlInP layer.
, A high reflectance close to 100% can be obtained. The AlGaInP layer has a thickness of 37 nm and the AlInP layer has a thickness of 51 nm, and is provided for 30 periods. At this time, the reflectance is almost 100% even in the vicinity of the blue wavelength range of 460 nm, while the reflectance is 20 in the vicinity of the green wavelength range of 530 nm.
Although it has a low reflectivity of about 30%, the laser light of blue or green is shielded by the above-described high reflection film so as not to pass through the AlGaInP layer having a relatively small band gap, and is emitted to the opposite side. This is not a problem, regardless of practicality. Also, as shown in FIG. 7, the AlGaInP layer and the AlInP
The layer can be used to form a highly reflective film only in the green wavelength range. It is also possible to add a periodic structure having a reflectance with respect to the wavelengths of FIGS. 6 and 7 to achieve a high reflectance in each of the blue, green and red wavelength ranges. Separately, in the red wavelength region, a high reflection film can be formed on the substrate side by a periodic structure of a dielectric film or a metal film, and this can be used. There is no problem even if the reflectance is obtained.

Further, the current injection can be realized by performing the current injection in the vertical direction of the substrate in the horizontal direction with respect to the vertical resonator structure for extracting the laser beam. At this time, the contact layer for the electrode is formed of the same semiconductor material as that of the semiconductor substrate or a semiconductor material having a larger forbidden band width than the semiconductor substrate, and in order to secure ohmic properties of the p-type layer or the n-type layer for the electrode. The band gap is very large and the carrier concentration can be set to at least 5 × 10 ¹⁸ to 1 × 10 ¹⁹ cm ^{−3 for} the p-type, and at least 1 × 10 ^{18 to} 5 × 10 for the n-type.
It is necessary to use a semiconductor material which can be set to ¹⁸ cm ^-3 or more.

[0014]

(Embodiment 1) An embodiment of the present invention will be described with reference to FIG. First, (100) using a 15.8 ° off the (511) tilt the substrate 1 from the surface, an undoped Al ₀ thereon. ₅ In _{0. 5} P layer
(d = 51 nm) and undoped _{(Al x1 Ga 1-x1)} 0. 5 In 0. 5 P layer (d = 37n
m, x ₁ = 0.1~0.2) a multi-periodic DBR structure high reflection film 2 provided 30 periods, an undoped _{(Al 0. 7 Ga 0.} 3) 0. 5 In 0. 5 P optical waveguide layer (d = 0.
4~1.0μm) 3, an undoped _{(Al 0. 5 Ga 0.} 5) 0. 5 In 0. 5 P quantum barrier (d = 5 to 10 nm) 4 layers and undoped Ga _x2 In _1-x2 P strained quantum well ( _{d = 3~13nm, x 2 = 0.55~0.70} ) 5 layers and undoped on both sides _{(Al 0. 5 Ga 0.} 5) 0. 5 in 0. 5 P light separation confinement layer (d = ten to six
0 nm), the multiple quantum well structure active layer 4, undoped (A
_{l 0. 7 Ga 0. 3} ) 0. 5 In 0. 5 P optical waveguide layer (d = 0.4~1.0μm) 5, p-type doped GaP layer _{(d = 5~10nm, N A =} 5 × 10 18 ~ 1 × 10 ¹⁹ cm ⁻³ ) 6 was first grown at a growth temperature of 7 by metalorganic chemical vapor deposition (MOCVD).
Epitaxially grow at 80 ° C. After this, SiO ₂
To make a mask by photolithography,
A p-type region is formed by performing Zn diffusion in the hatched area 7, and an n-type area is formed by performing Si diffusion in the hatched area 8. Next, the growth temperature 350 ° C. by molecular beam epitaxy (MBE), an undoped _{Zn 0. 75 Mg 0. 25} S 0. 35 S
e _{0. 65} layers (d = 55nm) and undoped ZnS _{0. 06} Se _{0. 94} layers (d = 34nm)
The provided 30 periods Multi periodic DBR structure high reflection film structure 9, an undoped _{Zn 0. 75 Mg 0. 25} S 0. 35 Se 0. 65 optical waveguide layer (d = 0.4~1.0μ
m) 10, an undoped ZnS _{0. 06} Se _{0. 94} quantum barrier (d = 5 to 10 nm)
Four layers and undoped Zn _x3 Cd _1-x3 Se strained quantum well (d = 5 to 15 nm, x
₃ = 0.2 to 0.3), five-layer and undoped ZnS ₀ on both sides. ₀₆ Se _{0. 94}
Light separate confinement layer (d = 10 to 60 nm) multi-quantum well structure active layer 11 was provided, undoped _{Zn 0. 75 Mg 0. 25} S 0. 35 Se 0. 65 optical waveguide layer (d = 0.4~1.0μm) 12, p-type doped GaP layer (d = 5-10n
m, N _A = 5 × 10 ^{18 -1} × 10 ¹⁹ cm ⁻³ ) 6, and further undoped Zn ₀ .
_{75 Mg 0. 25 S 0.} 35 Se 0. 65 layers (d = 43 nm) and undoped ZnS _{0. 06} S
e _{0. 94} layers (d = 26 nm) the 30 cycles provided multi periodic DBR structure high reflection film 13, an undoped _{Zn 0. 75 Mg 0. 25} S 0. 35 Se 0. 65 optical waveguide layer
(d = 0.4~1.0μm) 14, an undoped ZnS _{0. 06} Se _{0. 94} quantum barrier (d = 5~10nm) 4 layers and undoped ZnSe strained quantum well (d = 5 to 1
5 nm) 5-layer undoped ZnS ₀ on both sides. ₀₆ Se _{0. 94} multiple quantum well structure active layer 15 provided with the optical separate confinement layer, an undoped _{Zn 0. 75 Mg 0. 25} S 0. 35 Se 0. 65 optical Wave layer (d = 0.4 ~ 1.0
μm) 16, p-type doped GaP layer (d = 5 to 10 nm, N _A = 5 × 10 ¹⁸ to 1 ×
10 ¹⁹ cm ⁻³ ) 6 are epitaxially grown sequentially. After this,
As shown in FIG. 1, after forming a mask by photolithography, etching is performed in a mesa shape, and N ions are implanted into a hatched region using a mask, or Li, Na, or K of an alkali metal is diffused as an impurity. A p-type region 17 is formed, and halide ions I, Br, Cl
Alternatively, the n-type region 18 is formed by implanting F or by diffusing zinc halide as a raw material. Next, the semiconductor substrate 1 is formed by etching using a mask in the shape shown in FIG. 1, and then a high reflection film 19 is formed by a dielectric film, a metal film, or a combination thereof. At this time, the thickness of each dielectric film or metal film is set so that the reflectance becomes about 90% or more in the vicinity of the red wavelength region of 630 nm. For example, by providing a combination of SiO ₂ and Au for at least two periods, 90
% Or more can be easily obtained. Further, on the side opposite to the semiconductor substrate, a high reflection film 20 is formed,
The reflectance was set to be 70 to 90%, which was set to be relatively lower than the reflectance of the DBR structure high reflection film formed by crystal growth or the high reflection film formed on the substrate side. However, in order to require this reflectance range in a wide wavelength range of the visible region, a combination of a dielectric film and a metal film was provided periodically to fabricate. Further, by photolithography, etching and lift-off, p
The side electrode 21 and the n-side electrode 22 are vapor-deposited, cleaved and scribed, and cut into an element shape shown in the sectional view of FIG.

In this embodiment, when a current is injected from the lateral direction, laser oscillation is generated from the light emitting active layers 4, 11 and 15, and a red wavelength region around 630 nm and a green wavelength region 53 are emitted.
Oscillation wavelengths in the vicinity of 0 nm and in the vicinity of the blue wavelength range of 460 nm are obtained for the light emitting active layers 4, 11 and 15, respectively, and white laser light of three primary colors is extracted from the high reflection film 20 on the side opposite to the substrate. I was able to. In this embodiment, since the light-emitting active layers 4, 11, and 15 are simultaneously driven, the light-emitting layers always operate as a white laser light source in which three primary colors are mixed in the same space.

(Embodiment 2) Another embodiment of the present invention will be described with reference to FIG. An element is manufactured in the same manner as in Example 1 until the high reflection film 20 is formed. Thereafter, the p-side electrode 21 and the n-side electrode 22 are separately and independently vapor-deposited by photolithography, etching and lift-off, cleaved and scribed, and cut into the element shape shown in the sectional view of FIG.

In this embodiment, when a current is simultaneously injected into each electrode from the lateral direction, laser oscillation occurs from the light emitting active layers 4, 11 and 15, and the red wavelength region 630 as in the first embodiment.
Oscillation wavelengths in the vicinity of 300 nm, in the vicinity of the green wavelength range of 530 nm, and in the vicinity of the blue wavelength range of 460 nm are obtained for the light emitting active layers 4, 11, and 15, respectively. I was able to take it out. In addition, when a current is independently injected into each electrode, the red wavelength region around 630 nm corresponds to the current injection into each electrode.
Green wavelength range around 530nm and blue wavelength range 460n
An oscillation wavelength near m was obtained, and it was possible to drive independently to modulate the laser light of each oscillation wavelength at high speed. In this embodiment, when the light-emitting active layers 4, 11, and 15 are simultaneously driven, they operate as a white laser light source in which three primary colors are mixed in the same space, and red, green, or blue light is supplied by independent current injection to each electrode. The laser light having the oscillation wavelength was operated by being separated and extracted outside.

(Embodiment 3) Another embodiment of the present invention will be described with reference to FIG. First off from the (100) plane 15.8 ° off (511)
Using the tilted substrate 1, an undoped AlAs layer (d = 84n
m) and 20 cycles of undoped GaAs layer (d = 68nm)
DBR structure high reflection film 23, an undoped _{Al 0. 5 Ga 0. 5} As optical waveguide layer (d = 0.6~1.2μm) 24, an undoped GaAs quantum barrier (d = 5
~ 10 nm) 2 layers and undoped Ga _y1 In _1-y1 As strained quantum well (d = 3
~8nm, y ₂ = 0.2~0.3) 3-layer multiple quantum well structure active layer 25 thereof undoped GaAs optical separate confinement layers on both sides of (d = 10 to 60 nm) provided, an undoped _{Al 0. 5 Ga 0. 5} As Optical waveguide layer (d = 0.6 ~
1.2 μm) 26, p-type doped GaAs layer (d = 100 to 100 nm, N _A = 5 × 10
^{18 ~1 × 10 19 cm -3)} 27 the first metal organic chemical vapor deposition (MOC
The epitaxial growth is performed at a growth temperature of 750 ° C. by the VD) method. Thereafter, SiO ₂ is vapor-deposited and a mask is prepared by photolithography, Zn diffusion is performed in the shaded area 7 to form a p-type area, and Si diffusion is further performed in the shaded area 8 to form an n-type area. To form Next, an undoped InP layer (d = 2-3
[mu] m) and GaInP layer thin film layer therebetween (d = 5 to 10 nm) three layers introduced buffer layer 28, an undoped _{In 0. 83 Ga 0. 17} As 0. 4 P 0. 6
Multi-period DBR structure high reflection film 29 with 20 layers (d = 10 nm) and undoped InP layer (d = 94 nm), undoped InP optical waveguide layer
(d = 0.6~1.2μm) 30, an undoped _{In 0. 83 Ga 0. 17} As 0.
₄ P _{0. 6} quantum barrier (d = 7~10nm) 4 layers and undoped InGaAsP strained quantum well (d = 5 to 15 nm) undoped an In ₀ 5 layer and on both sides thereof.
_{83 Ga 0. 17 As 0.} 4 P 0. 6 Light separate confinement layer (d = 10 to 60 nm) multi-quantum well structure active layer 31 was provided, undoped InP optical waveguide layer (d = 0.6~1.2μm) 32, p-type doped GaAs layer (d = 5-10n
m, N _A = 5 × 10 ¹⁸ to 1 × 10 ¹⁹ cm ⁻³ ) 27 is epitaxially grown. Thereafter, SiO ₂ is vapor-deposited and a mask is prepared by photolithography.
The n-type region is formed by forming a mold region and further diffusing Si into the hatched portion 8. Further, in the next growth temperature 600 ° C. by MOCVD, an undoped In _{0. 83} Ga _{0. 17}
As _{0. 4} P _{0. 6} Layers (d = 119 nm) and undoped InP layer (d = 112nm) 2
Multi-period DBR structure high reflection film 33 with zero period, undoped I
nP optical waveguide layer (d = 0.6~1.2μm) 34, an undoped In _{0. 83} G
_{a 0. 17 As 0. 4} P 0. 6 quantum barrier (d = 7~10nm) 4 layers and undoped G
a _y2 In _1-y2 As strained quantum well _{(d = 5~15nm, y 2 =} 0.6~0.7) 5 -layer and Andou In ₀ on both _{sides. 83 Ga 0. 17 As 0} . 4 P 0. confinement ₆ light separation Multiple quantum well structure active layer 35 provided with layers, undoped InP optical waveguide layer (d = 0.6 to 1.2 μm) 36, p-type doped GaAs
Layers (d = 5 to 10 nm, N _A = 5 × 10 ¹⁸ to 1 × 10 ¹⁹ cm ⁻³ ) 27 are sequentially epitaxially grown. After that, SiO ₂ is vapor-deposited and a mask is prepared by photolithography,
A p-type region is formed by performing Zn diffusion, and an n-type region is formed by performing Si diffusion in the hatched portion 8. Further, by combining a dielectric film with the bottom of the substrate 1,
The high reflection film 19 having a reflectance in the range of 70 to 90% is formed. The reflective film has a thickness of at least 900 to 1600 nm.
In this range, a structure having the above-mentioned reflectance uniformly is adopted.
Next, after forming a mask by photolithography,
As shown in FIG. 3, etching is performed in a mesa shape, and a high reflection film 20 is formed by a combination of a dielectric film and a metal film. At this time, at least in the range of 900 to 1600 nm,
The thickness of each dielectric film or metal film is set so that the reflectance is about 99% or more. For example, by providing a combination of SiO ₂ and Au for at least two periods, a reflectance of 99% or more can be easily obtained in the above wavelength range.
On the other hand, the multi-period DBR structure high-reflection films 23, 29 provided under the light-emitting active layers 25, 31, and 35, respectively.
And 33 have an oscillation wavelength of around 980 nm, around 1300 nm, and around 1550 nm, respectively.
It is assumed to be in the range of 70 to 90%. As a result, all the laser beams emitted from the light emitting active layers 25, 31 and 35 are directed to the semiconductor substrate side where there is no problem of light absorption. Thereafter, in the same manner as in Example 2, the p-side electrode 21 and the n-side electrode 22 are separately and independently vapor-deposited by photolithography and etching and lift-off, and cleaved and scribed to form the element shown in the sectional view of FIG. cut.

In this embodiment, when a current is simultaneously injected into each electrode from the lateral direction, the light emitting active layer 25,
Laser oscillation occurs simultaneously from 31 and 35, and the wavelength range 98
Around 0 nm, around 1300 nm wavelength range and 155 wavelength range
Oscillation wavelengths around 0 nm were obtained correspondingly, and laser light could be extracted from the substrate side. Further, when a current is independently injected into each electrode, the wavelength region around 980 nm and the wavelength region 1300 correspond to the current injection into each electrode.
Oscillation wavelengths in the vicinity of 1 nm and in the wavelength range of 1550 nm were obtained, and it was possible to drive independently to modulate the laser light of each oscillation wavelength at high speed. In this embodiment, when the light-emitting active layers 25, 31 and 35 are simultaneously driven, an oscillation wavelength of 1550 nm suitable for high-speed long-distance optical communication, which is a low-loss transmission wavelength region of an optical fiber, in the same space, In order to transmit a laser beam having an oscillation wavelength of 1300 nm suitable for a high-speed modulation or a phase shift at the same time, and to transmit those signals over a longer distance, an excitation light source is provided to an Er-doped optical fiber amplifier. A wavelength-multiplexed signal could be transmitted while amplifying and amplifying a laser beam having an oscillation wavelength of 980 nm.

[0020]

According to the present invention, it is possible to take out a multi-wavelength laser light source in the same space by vertically stacking and integrating at least two or more sets of active layer structures having different oscillation wavelengths on the same semiconductor substrate. A multi-wavelength surface emitting semiconductor laser device with a vertical cavity structure with very low light absorption has been realized. For example, when current is simultaneously injected into each of the electrodes separated so that they can be driven independently from the lateral direction, oscillation wavelengths in the vicinity of a red wavelength range of 630 nm, a green wavelength range of 530 nm, and a blue wavelength range of 460 nm are obtained. It was possible to extract a white laser light in which primary colors were mixed. When a current is independently injected into each of the above electrodes, the red wavelength region around 630 nm, the green wavelength region around 530 nm, and the blue wavelength region 46 correspond to the current injection into each electrode.
It was possible to separate laser light having an oscillation wavelength near 0 nm, operate the laser light independently, and drive independently to modulate the laser light of each oscillation wavelength at high speed.

Furthermore, an InGaAsP / InP semiconductor laser having an oscillation wavelength of 1550 nm used for high-speed long-distance optical communication and an oscillation wavelength of 1300 nm used for short-medium-distance optical communication is integrated in a surface-emitting type, and oscillated in the same space. The wavelength-division multiplexing optical communication with different wavelengths is enabled, and simultaneously the Er-doped optical fiber amplifier is excited by an integrated InGaAs / GaAs semiconductor laser having an oscillation wavelength of 980 nm, and the transmitted signal is amplified to extend the transmission distance. The speed of long-distance and short-medium-distance optical communication was improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an element structure showing one embodiment of the present invention.

FIG. 2 is a sectional view of an element structure showing another embodiment of the present invention.

FIG. 3 is a sectional view of an element structure showing another embodiment of the present invention.

FIG. 4 is a diagram showing the wavelength dependence of the reflectance of a DBR structure reflective film made of a ZnSSe layer and a ZnMgSSe layer.

FIG. 5 is a diagram showing the wavelength dependence of the reflectance of a DBR structure reflective film made of a ZnSSe layer and a ZnMgSSe layer.

FIG. 6 is a diagram showing the wavelength dependence of the reflectance of a DBR-structured reflective film composed of an AlGaInP layer and an AlInP layer.

FIG. 7 is a diagram showing the wavelength dependence of the reflectance of a DBR-structured reflective film composed of an AlGaInP layer and an AlInP layer.

[Explanation of symbols]

1 ... (511) GaAs tilted substrate 15.8 ° off from (100) plane
2 ... High reflection film with DBR structure by AlInP layer and AlGaInP layer, 3 ... A
lGaInP optical waveguide layer, 4 ... GaInP / AlGaInP strained multiple quantum well structure active layer, 5 ... AlGaInP optical waveguide layer, 6 ... GaP contact layer, 7 ... Zn diffusion or ion implanted p-type region, 8 ... Si
Diffusion or ion implantation n-type region, 9 ... ZnMgSSe layer and Z
DBR structure high reflection film by nSSe layer, 10 ... ZnMgSSe optical waveguide layer, 11 ... ZnCdSe / ZnSSe strained multiple quantum well structure active layer, 1
2 ... ZnMgSSe optical waveguide layer, 13 ... DBR structure high reflection film by ZnMgSSe layer and ZnSSe layer, 14 ... ZnMgSSe optical waveguide layer, 15 ... Zn
Se / ZnSSe strained multiple quantum well structure active layer, 16 ... ZnMgSSe optical waveguide layer, 17 ... Zn diffusion or ion implantation p-type region,
18 n-type diffusion or ion-implanted region, 19 high reflection film made of dielectric film, 20 high reflection film made of dielectric film and metal film, 21 p-side electrode, 22 n-side electrode, 23 Al
DBR structure high reflection film composed of As layer and GaAs layer, 24 ... AlGaAs optical waveguide layer, 25 ... GaInAs / GaAs strained multiple quantum well structure active layer, 26 ... AlGaAs optical waveguide layer, 27 ... GaAs contact layer,
28: GaInP / InP buffer layer, 29: DBR structure high reflection film composed of InGaAsP layer and InP layer, 30: InP optical waveguide layer, 31: In
GaAsP / InGaAsP strained multiple quantum well structure active layer, 32 ... InP optical waveguide layer, 33 ... DBR structure high reflection film by InGaAsP layer and InP layer, 34 ... InP optical waveguide layer, 35 ... InGaAs / InGaAsP strained multiple quantum well structure active layer Layer, 36 ... InP optical waveguide layer.

Claims (14)

(57) [Claims] 1. A multi-wavelength having different oscillation wavelengths, wherein at least two or more combinations of a light-emitting active layer having a small bandgap and an optical waveguide layer having a large bandgap sandwiching the active layer are stacked vertically on a semiconductor substrate. When the light source is a laser light source and the bandgap of the light emitting active layer is smaller than the semiconductor substrate, a laser beam having a smaller forbidden band width of the light emitting active layer as it is stacked above the semiconductor substrate and having a longer oscillation wavelength as it goes upward. And a vertical cavity structure in which a high-reflection film for extracting laser light from the semiconductor substrate is laminated, or the forbidden band width of the light-emitting active layer laminated on the semiconductor substrate is larger than that of the semiconductor substrate. When it is larger, the bandgap of the light emitting active layer is set to be larger as the layer is stacked above the semiconductor substrate, and set so that a laser beam having a shorter oscillation wavelength is emitted upward, and the laser beam is emitted from the side opposite to the semiconductor substrate. The semiconductor laser element characterized by having a surface emission type multiple wavelength laser light source for a vertical resonator structure formed by laminating a high-reflection film to extract light on the same substrate. 2. The semiconductor laser device according to claim 1, wherein each of the light emitting active layers stacked on the same substrate emits laser beams having different oscillation wavelengths through the same space in the same direction by a vertical resonator structure. Each luminescent active layer may be driven simultaneously by exactly the same electrode and injected with current, or each luminescent active layer may be independently driven by an independent separated electrode, and a current may be applied to each luminescent active layer in the lateral direction. A semiconductor laser device wherein injection is performed. 3. The semiconductor laser device according to claim 1, wherein when the bandgap of said light emitting active layer is smaller than said semiconductor substrate, a multi-wavelength laser light source emits light through said semiconductor substrate. Or a vertical cavity structure in which a highly reflective film emitting from the side opposite to the semiconductor substrate is laminated. 4. The semiconductor laser device according to claim 1 , wherein the multi-wavelength laser light sources having different oscillation wavelengths are separated from each other by an energy of 50 meV or more , and the forbidden band width of the light emitting active layer is set to be less than 50 meV. 60 meV or less from semiconductor substrate
When it is below , the laser light is taken out from the semiconductor substrate side, and a vertical resonator structure that emits laser light having a longer oscillation wavelength from the semiconductor substrate to the upper side is used, or the forbidden band width of the light emitting active layer is the same as that of the semiconductor substrate. 60 meV or more from the substrate
That sometimes, the and to take out the laser light from the side opposite to the semiconductor substrate, a semiconductor laser device characterized by a vertical cavity structure for emitting short laser beam oscillation wavelengths as upward from the semiconductor substrate. 5. A semiconductor laser device according to claim 1 , wherein, when extracting laser light from the semiconductor substrate side, lattice strain that causes a compressive or tensile strain is introduced into the light emitting active layer. A semiconductor laser device, wherein the forbidden band width of the light emitting active layer is 60 meV or less than that of the semiconductor substrate. 6. The semiconductor laser device according to claim 1 , wherein said highly reflective film grown on said semiconductor substrate is made of at least two kinds of semiconductor materials having different refractive indexes. Desirably, when the semiconductor substrate and the lattice constant are formed of the same semiconductor material, and the refractive index of the semiconductor material with respect to the oscillation wavelength λ is represented by n, the thickness d of each semiconductor material is represented by λ / 4n, The semiconductor laser device according to claim 1, wherein the high reflection film has a periodic structure. 7. The semiconductor laser device according to claim 1, wherein said high-reflection film has a periodic structure of at least two types of semiconductor materials having different refractive indexes, and has a period of at least 10 periods. Semiconductor laser device characterized by being in the range of 10 to 40 periods. 8. The semiconductor laser device according to claim 1 , wherein the high-reflection film provided at the uppermost portion of the growth layer laminated on the semiconductor substrate or at the lowermost portion of the semiconductor substrate is a dielectric film. A semiconductor laser device comprising a periodic structure of a body film, a metal film, or a combination thereof. 9. The semiconductor laser device according to claim 1 , wherein the contact layer for the electrode is formed of the same semiconductor material as the semiconductor substrate or a semiconductor material having a larger band gap than the semiconductor substrate. A semiconductor laser device wherein the p-type carrier concentration is set to 5 × 10 ¹⁸ cm ⁻³ or more, and the n-type carrier concentration is set to 1 × 10 ¹⁸ or more . 10. The semiconductor laser device according to claim 9, wherein
The contact layer for the electrode is GaAs _1-x P _x (0 ≦ x
≦ 1)
User element. 11. The semiconductor laser device according to claim 1, wherein the p-type and n-type semiconductor layers are formed by impurity diffusion or ion implantation, and are each set to have a carrier concentration equal to or higher than said carrier concentration . A semiconductor laser device characterized by the above-mentioned. 12. The semiconductor laser device according to claim 1 , wherein said semiconductor substrate has a substrate plane orientation.
(001) direction from (110) [1-1-0] direction or (11-0) [1-1
A semiconductor laser device having a substrate surface inclined at 0 ° to 54.7 ° in the [0] direction. 13. The semiconductor laser device according to claim 12,
And (110) [1-1-0] direction from the (001) plane of the substrate surface
Or, the inclination angle in the [11-0] [1-10] direction is 5 ° or more and 30 °
A semiconductor laser device characterized by the following. 14. The semiconductor laser device according to claim 1 , wherein the crystal layer on the semiconductor substrate is formed by a metal organic chemical vapor deposition (MOCVD) method, a molecular beam epitaxy (MBE) method, or a gas source molecule. A semiconductor laser device grown by a line epitaxy (GSMBE) method.