JP3040262B2 - 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 distributed feedback type or distributed reflection type semiconductor laser having a wavelength in the visible region, a stable oscillation wavelength over a wide temperature range, and a low operating current, which is suitable as a light source for optical information processing. -The device.

[0002]

2. Description of the Related Art A conventional semiconductor laser device will be described below. FIG. 9 is a perspective view of a main part of a conventional distributed feedback type semiconductor laser device (Preliminary Collection 28a-ZP-3 of Spring 1988, or IEEE Journal of Quantum).
Electron. Vol.25 p.1489 (1989)). An n-type GaAs current blocking layer 22 having a window 22a serving as a current channel on a p-type gallium arsenide (GaAs) substrate 21
Is formed thereon, and a p-type gallium aluminum arsenide (Ga _0.5 Al _0.5 As) cladding layer 23 and a p-type Ga
_0.87 Al _0.13 As active layer 24, n-type Ga _0.5 Al _0.5 A
n-type Ga having an s barrier layer 25 and a diffraction grating 26a
_0.75 Al _0.25 As light guide layer 26, n-type Ga _0.25 Al
_{A 0.75} As clad layer 27 and an n-type GaAs contact layer 28 are formed.

In the structure shown in FIG. 9, a current injected from a p-type GaAs substrate 21 is effectively confined in a window 22a, and laser oscillation occurs in the active layer 24 above the window 22a. At this time, since the band gap of the GaAs current blocking layer 22 is smaller than the energy of the wavelength of the laser light, the laser light is absorbed by the current blocking layer 22 in a region other than the window 22a. It is confined and a single transverse mode laser oscillation is obtained. In this manner, the laser oscillates in a distributed feedback (hereinafter, abbreviated as DFB) mode by the diffraction grating 26a present on the light guide layer 26, so that a wavelength stable laser light source having no mode hop over a wide temperature range can be obtained.

[0004]

However, the above conventional structure has a problem that the threshold and efficiency are limited by the absorption of laser light by the GaAs current blocking layer, and as a result, the operating current value becomes high. I was

That is, an increase in the operating current value causes heat generation of the element, especially at the time of high output, and makes the gain distribution longer. At this time, the semiconductor laser deviates from the oscillation in the DFB mode at the wavelength determined by the diffraction grating, and oscillates in the Fabry-Perot (hereinafter abbreviated as FP) mode. Therefore, there is a problem that the oscillation wavelength becomes unstable at high output.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a semiconductor laser device having a low operating current.

[0007]

SUMMARY OF THE INVENTION The semiconductor laser device of the present invention in order to achieve this goal, one conductivity on at least one side of the main surface of the active <br/> layer of Ga _1-X Al _X As Type Ga _1-Y1
A first light guide layer of Al _Y1 As , and on the first light guide layer
Of one conductivity type having a diffraction grating on the entire Ga _1-Y2 Al _Y2 A
a second optical guide layer of the s, and the current blocking layer of Ga _1-Z Al _Z As of the opposite conductivity type having a stripe-shaped window in said second optical guide layer, the first conductivity type in said stripe-shaped window Ga
_1-Y3 and Al _Y3 As cladding layer is formed, and AlA
s between X, Y1, Y3 and Z, which determine the mixed crystal ratio,
>Y3>Y2> X ≧ 0, and Y1> Y2. Further, the semiconductor laser device of the present invention has a Ga _1-X
Lead to at least one side of the main surface of the active layer of Al _X As
A first light guide layer of Ga _1-Y1 Al _Y1 As
Second layer of one-conductivity-type Ga _1-Y2 Al _Y2 As on one light guide layer
A light guide layer, and a stripe-shaped light guide layer on the second light guide layer.
Ga of the opposite conductivity type having a window _1-Z Al Z As current blocking
Layer and GaAs having a diffraction grating on the current blocking layer
One conductivity type for the sAl protective layer and the striped window
And a cladding layer of Ga _1-Y3 Al _Y3 As
Between X, Y1, Y3 and Z that determine AlAs mixed crystal ratio
Have the following relationship: Z>Y3>Y2> X ≧ 0, Y1> Y2
Things. Further, the semiconductor laser device of the present invention
One-conductivity type GaAlAs having a folded grating on the entire surface of the layer
A first class of one conductivity type GaAlAs is formed on the three light guide layers.
And a Ga _{1 -x} Al _x As layer on the first cladding layer .
An active layer, and Ga ₁ -Y ₁ Al _Y1 A of opposite conductivity type on the active layer;
s first light guide layer and a reverse conductive layer on said first light guide layer
A second light guide layer of Ga _1-Y2 Al _Y2 As
One conductivity type G having a striped window on the light guide layer
a _{1 -Z} Al _Z As current blocking layer and the stripe
Second window of Ga _{1 -Y 3} Al _Y3 As of opposite conductivity type
X and Y that determine the AlAs mixed crystal ratio
1, Y3 and Z, Z>Y3>Y2> X ≧ 0,
A semiconductor laser device having a relationship of Y1> Y2. Also book
The semiconductor laser device of the invention, the active layer of Ga _1-X Al X As
First light guide layer of one conductivity type Ga ₁ -Y ₁ Al _Y1 As
To the exposed surface near the end surface on the first light guide layer.
Ga _1-Y2 Al _Y2 As second optical guide layer having a folded grating
On the second light guide layer not having the diffraction grating.
Opposite conductivity type Ga having a stripe-shaped window of _1-Z Al _Z As
One conductive layer for the current blocking layer and the striped window
And a cladding layer of Ga _1-Y3 Al _Y3 As is formed.
X, Y1, Y3, and Z that determine the AlAs mixed crystal ratio
The relationship of Z>Y3>Y2> X ≧ 0 and Y1> Y2
Is what you do. Further, the semiconductor laser device of the present invention,
The semiconductor laser device according to claim 1 or claim 7.
Wherein the active layer has a quantum well structure.

[0008]

[Action] With this configuration, the laser beam due to the presence of Ga _1-Y3 Al _Y3 high mixed crystal ratio than As layer Ga _1-Z Al _Z As current blocking layer is confined to the stripe. At this time, since the current blocking layer is transparent to the laser light, no absorption of the laser light occurs. Further, the wavelength is stabilized with respect to a wide temperature range and a change in optical output due to the presence of the diffraction grating.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a main part of a semiconductor laser device according to a first embodiment of the present invention. n-type GaAs
An n-type GaAs buffer layer 2 is formed on an s-substrate 1, and an n-type Ga _0.5 Al _0.5 As clad layer 3, a Ga _0.85 Al _0.15 As active layer 4, and a p-type Ga _0.5
An Al _0.5 As first light guide layer 5 and a p-type Ga _0.8 Al _0.2 As second light guide layer 6 having a diffraction grating 6 a in the resonator direction are formed. The period of the diffraction grating is a period that is an integral multiple of the wavelength in the medium. In order to further enhance the wavelength selectivity, the period at the center of the diffraction grating is set to １ ／ of the wavelength in the medium.
You can just shift. On the diffraction grating 6a, there is provided a window 7a serving as a current channel for current confinement.
A Ga _0.4 Al _0.6 As current blocking layer 7 is formed, and a p-type Ga _0.5 Al _0.5 As cladding layer 9 is formed on the window 7 a. 8 Ga _0.8 Al _{0 .2} As protective layer, 10 is a p-type GaAs contact layer.

Here, in order to obtain stable single transverse mode oscillation, the AlAs mixed crystal ratio of the current blocking layer 7 is changed to p-type Ga
_{It is} set higher than the AlAs mixed crystal ratio of the _0.5 Al _0.5 As cladding layer 9. If the AlAs mixed crystal ratio of the current blocking layer 7 is almost the same as that of the cladding layer 9, the refractive index in the stripe is reduced due to the plasma effect, and it becomes an anti-guide waveguide, so that a single transverse mode oscillation cannot be obtained. When the AlAs mixed crystal ratio of the current blocking layer 7 is lower than that of the p-type Ga _0.5 Al _0.5 As clad layer 9, the transverse mode becomes completely unstable. In the present embodiment, as shown in FIG.
Is 0.1 higher than the AlAs mixed crystal ratio of the p-type Ga _0.5 Al _0.5 As clad layer 9 and 0.6.

In this structure, the p-type GaAs contour
Current injected from the contact layer 10 is trapped in the window 7a.
And the lower Ga of the window 7a_0.85Al_0.157 in As active layer 4
Laser oscillation in the 80 nm band occurs. Here, p-type Ga
_0.5Al_0.5Utilizing the AlAs mixed crystal ratio of the As first light guide layer 5
Sufficiently higher than the AlAs mixed crystal ratio of the conductive layer 4,
Effective carrier confinement in layer 4 enables oscillation in the visible region
And In order to obtain 780nm laser oscillation
Requires an AlAs mixed crystal ratio of 0.45 or more,
In this embodiment, it is set to 0.5. The regrowth is based on the AlAs mixed crystal ratio.
Low p-type Ga _0.8Al_0.2As on the second light guide layer 6
, So there is no problem of surface oxidation. Also the
Regarding the AlAs mixed crystal ratio of the two light guide layers 6, regrowth is inevitable.
0.3 or less, transparent to the laser oscillation wavelength.
It is desirable to set it to 0.2 in this embodiment. Sa
Furthermore, the film thickness does not significantly affect the light distribution.
5 μm or less is desirable, and in this embodiment, it is set to 0.03 μm.
ing. As described above, in this embodiment, the carrier is confined.
Layer (first light guide layer 5) and a layer to be regrown (second light guide layer 5).
The formation in the visible region can be achieved by separately forming the
It is possible to shake. In addition, n-type Ga_0.4Al_0.6
The band gap of the As current blocking layer 7 is Ga_0.85Al_0.15A
Since it is larger than the forbidden band width of the s active layer 4, the current block
Low operation with no light absorption by layer 7 and low waveguide loss
A current element is obtained.

In the structure of this embodiment, the refractive index in the medium changes periodically due to the presence of the diffraction grating 6a, and light traveling parallel to the resonator direction is periodically reflected. The diffraction grating 6a has a period that is an integral multiple of the wavelength in the medium.
Since the light reflected by the diffraction grating 6a has the same phase, the wavelength selectivity is enhanced. Therefore, single longitudinal mode oscillation can be maintained against temperature changes, fluctuations in optical output, high-speed modulation, and the like.

FIGS. 2A to 2C are views showing the steps of manufacturing a semiconductor laser device according to an embodiment of the present invention. First, FIG.
As shown in FIG. 1A, an MO is placed on an n-type GaAs substrate 1.
N-type GaAs buffer layer 2, n-type Ga _0.5 Al _0.5 As clad layer 3, G
a _0.85 Al _0.15 As active layer 4, p-type Ga _0.5 Al _{0. 5} A
The s first light guide layer 5 and the p-type Ga _0.8 Al _0.2 As second light guide layer 6 are grown. Next, a diffraction grating is patterned on the resist film by a two-beam interference exposure method using a He-Cd laser as a light source, and the diffraction grating 6a is etched.
To form

Next, as shown in FIG. 2B, n-type Ga
_0.4 Al _0.6 As current blocking layer 7 and Ga _0.8 Al _0.2
The As protective layer 8 is grown again by the MOCVD method or the MBE growth method, and the striped window 7a is formed by photoetching. As an etching method, first, an etchant such as tartaric acid or sulfuric acid, which is not so selective with respect to the AlAs mixed crystal ratio, is etched halfway through the Ga _0.4 Al _0.6 As current blocking layer 7 and then hydrofluoric acid or phosphoric acid Ga _0.4 Al _0.6 using an etchant capable of selectively etching a layer having a high AlAs mixed crystal ratio such as a system.
The As current blocking layer 7 is etched. Note that p-type G
Since the a _0.8 Al _0.2 As second optical guide layer 6 also functions as an etching stop layer, variation due to etching is small, and a high yield can be obtained. At this time, the stripe width was 2 μm. Note that the stripe shape is preferably a forward mesa shape rather than an inverted mesa shape. That is, crystal growth is more difficult in the case of the inverted mesa shape than in the case of the forward mesa shape, and the yield may be reduced due to the deterioration of the characteristics. Actually, in the case of the inverted mesa shape, the crystallinity of GaAlAs grown on the side portion of the window 7a was impaired, and the threshold current of the manufactured device was increased by about 10 mA as compared with the forward mesa shape device. The characteristics of the element described later show a forward mesa shape. Protective layer 8 is required to protect the top of the n-type Ga _{0. 4} Al _0.6 As current blocking layer 7 from the surface oxidation. AlA of the protective layer 8
As with the second optical guide layer, the s mixed crystal ratio is desirably 0.3 or less, which facilitates regrowth, and is a transparent mixed crystal ratio with respect to laser light.

Next, as shown in FIG.
Ga _0.5 Al _0.5 As by p-type or MBE growth
The cladding layer 9 and the p-type contact layer 10 are formed by regrowth. At this time, A
Since the growth is performed on the p-type Ga _0.8 Al _0.2 As second optical guide layer 6 having a low lAs mixed crystal ratio, the growth can be easily performed.
However, when Zn is used as a dopant for the p-type Ga _0.5 Al _0.5 As clad layer 9, the diffusion of Zn during regrowth into the stripe region affects the characteristics.
The carrier concentration should be at least 10 ¹⁸ c at the regrowth interface.
m ^-3 or less. In this embodiment, 7 × 10 ¹⁷ c
m ^-3 . There is also a method of using a dopant that does not diffuse much, such as carbon, instead of Zn. Finally, n-type G
aAs substrate 1 side and p-type GaAs contact layer 10
An electrode is formed on each side.

In FIGS. 2A to 2C, the conductivity types of the active layer 4 and the protective layer 8 are not particularly described, but they may be p-type, n-type, or non-doped. No problem. The thickness of the current blocking layer 7 is required to be at least 0.4 μm because the laser beam is absorbed by the upper p-type GaAs contact layer 10 if the current blocking layer 7 is thin.

In this embodiment, the diffraction grating formed on the p-type Ga _0.8 Al _0.2 As second light guide layer 6 is described, but the diffraction grating is formed on the Ga _0.8 Al _0.2 As protective layer 8 or on the active layer. It may be formed below the layer 4.

FIG. 3 is a perspective view of a main part of a semiconductor laser device according to a second embodiment of the present invention. As shown in FIG.
In this embodiment, the diffraction grating 8a is formed on the Ga _0.8 Al _0.2 As protective layer 8. Manufacturing method of this structure, grown up Ga _{0. 8} Al _0.2 As protective layer 8 by first growing, forming a diffraction grating 8a thereon. Next, after a window 7a serving as a current channel is formed in the current blocking layer 7 and the protective layer 8 by etching, the p-type Ga _0.5
Al _0.5 As clad layer 9 and p-type GaAs layer 10
Grow.

FIG. 4 is a perspective view of a main part of a semiconductor laser device according to a third embodiment of the present invention. As shown in FIG.
In this embodiment, a diffraction grating 11a is formed below the active layer 4. The manufacturing method in this structure is an n-type Ga _0.8
After growing up to the Al _0.2 As third light guide layer 11, a diffraction grating 11a is formed. Next, after growing up to the p-type Ga _0.8 Al _0.2 As protective layer 8, a window 7a serving as a current channel is formed. A p-type Ga _0.5 Al _0.5 As clad layer 9
And a p-type GaAs layer 10 is grown.

The second light beam near at least one of the end faces
Distributed reflection with a diffraction grating formed on the id layer in the direction of the cavity
The same effect can be obtained with a type (hereinafter abbreviated as DBR) laser.
Is obtained. FIG. 5 shows a semiconductor device according to a fourth embodiment of the present invention.
FIG. 2 is a perspective view of a main part of a body laser device, which is a DBR laser.
The case is shown. Manufacturing method in this structure
Is Ga _0.8Al_0.2Single crystal growth up to As protective layer 8
After etching the window 7a, p-type Ga_0.5
Al_0.5As clad layer 9 and p-type GaAs layer 10
And finally, the end face is p-type Ga_0.8Al_0.2As
Etching until layer 6 is exposed to form diffraction grating 6a
I do. At this time, etch the stripe part
The method of selective etching used for etching is used. DBR Les
The laser beam is diffracted depending on the period of the diffraction grating.
Can be taken out at right angles to the
A current surface emitting laser can be realized.

FIG. 6 is a diagram showing current-light output characteristics of a semiconductor laser device according to one embodiment of the present invention. Compared with the conventional example, there is no light absorption in the current block layer 7, so that a low operating current can be realized.
100m for devices with% / 75% coating
An optical output of W or more is obtained. The transverse mode also oscillates in a stable basic mode up to high output.

FIG. 7 is a diagram showing the optical output dependency of the oscillation wavelength of the semiconductor laser device according to one embodiment of the present invention. Conventionally, at 50 mW or more, the heat generated by the element causes mode hop to the wavelength of the Fabry-Perot mode, causing a change in wavelength. On the other hand, the structure of the present invention has a stable DFB up to 100 mW.
Mode oscillation was obtained.

FIG. 8 is a diagram showing the temperature dependence of the oscillation wavelength of the semiconductor laser device according to one embodiment of the present invention. In the structure of the present invention, a stable laser oscillation without a mode hop is obtained up to 80 ° C. at the time of high output of 50 mW, and excellent characteristics are obtained particularly at the time of high-temperature operation as compared with the conventional example.

Since the threshold value can be reduced by forming the active layer 4 in the quantum well structure, a low operating current and a high output can be achieved, and the various characteristics shown in FIGS. 6 to 8 can be further improved. it can. 780n as quantum well structure
Ga _0.95 Al _0.05 A with a thickness of 10 nm oscillating in the m band
Four s-well layers and 4 nm-thick Ga _0.7 Al _0.3 As
Multiquantum well consisting of five barrier layers (MQ
When the W) structure was used, an optical output of 200 mW or more was obtained. Note that other quantum well structures, that is, a single quantum well (SQW) structure and a double quantum well (DQ
The same applies to a W) structure, a triple quantum well (TQW) structure, a gulin (GRIN) structure, or a separate confinement heterostructure (SCH) structure.

In all the above embodiments, n-type Ga
Although the case where the As substrate 1 and the n-type current blocking layer 7 are used has been described, the p-type GaAs substrate 1 may be p-type and the p-type current blocking layer may be used. That is, this is because the AlAs mixed crystal ratio of the current blocking layer 7 is high, and in the case of a p-type GaAlAs layer having a high AlAs mixed crystal ratio, diffusion of electrons is suppressed, so that a p-type block layer can be realized. is there.

[0026]

As described above, according to the present invention, the G
a _first conductivity type Ga _1-Y1 Al _Y1 As first light guide layer and a Ga _1-Y2 Al _Y2 As second light guide layer having a diffraction grating on at least one side of the main surface of the a _1-x Al _x As layer Is formed on the second light guide layer, and a Ga ₁ -Z Al _Z As current blocking layer of a reverse conductivity type having a striped window is formed on the second light guide layer. _1-Y3 Al
_{A Y3} As layer is formed and Z>Y3>Y2> between X, Y1, Y2, Y3 and Z that determine the AlAs mixed crystal ratio.
With a configuration satisfying the relationship of X ≧ 0 and Y1> Y2, it is possible to easily realize a semiconductor laser device having a stable oscillation wavelength and a low operating current with respect to a temperature change, a change in optical output and the like. is there.

Further, in the semiconductor laser of the present invention, since the AlAs mixed crystal ratio of the current blocking layer is set to be higher than the AlAs mixed crystal ratio of the cladding layer, the semiconductor laser oscillates in a single transverse mode, and the laser beam has a current blocking layer. Since there is no light absorption, a low operating current value can be obtained. Further, by forming a diffraction grating, it is possible to oscillate in a wavelength-stable DFB mode. By reducing the operating current, the amount of heat generated by the element at the time of high output can be reduced, so that a mode hop to the Fabry-Perot mode is suppressed, and a semiconductor laser having a stable oscillation wavelength up to high output can be obtained.

Further, since the amount of heat generated in the laser mount portion can be reduced by lowering the operating current, a small and lightweight heat sink can be used. The size and cost can be reduced.

By using the semiconductor laser device having the above-described effects in the field of optical information processing, a great effect is achieved in miniaturization and high performance of optical information processing equipment.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a semiconductor laser device according to a first embodiment of the present invention.

FIGS. 2A to 2C are manufacturing process diagrams of a semiconductor laser device according to an embodiment of the present invention;

FIG. 3 is a perspective view of a main part of a semiconductor laser device according to a second embodiment of the present invention.

FIG. 4 is a perspective view of a main part of a semiconductor laser device according to a third embodiment of the present invention.

FIG. 5 is a perspective view of a main part of a semiconductor laser device according to a fourth embodiment of the present invention.

FIG. 6 is a diagram showing current-light output characteristics of a semiconductor laser device according to one embodiment of the present invention.

FIG. 7 is a diagram showing the optical output dependence of the oscillation wavelength of the semiconductor laser device according to one embodiment of the present invention.

FIG. 8 is a diagram showing the temperature dependence of the oscillation wavelength of the semiconductor laser device according to one embodiment of the present invention.

FIG. 9 is a perspective view of a main part of a conventional semiconductor laser device.

[Explanation of symbols]

4 Ga _0.85 Al _0.15 As active layer (Ga _1-x Al _x As active layer) 5 Ga _0.5 Al _0.5 As first optical guide layer (Ga _1-Y1 Al
_Y1 As first light guide layer) 6 Ga _0.8 Al _0.2 As second light guide layer (Ga _{1 -Y 2} Al)
_Y2 As the second light guide layer) 7 Ga _0.4 Al _0.6 As current blocking layer (Ga _1-Z Al Z
As current blocking layer) 7a striped window 9 Ga _0.5 Al _0.5 As cladding layer (Ga _1-Y3 Al _Y3 A
s cladding layer)

Continuation of the front page (72) Inventor Kunio Ito 1006 Kazuma Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electronics Corporation (56) References JP-A-63-136586 (JP, A) JP-A-3-238886 (JP) JP-A-4-165688 (JP, A) JP-A-60-66484 (JP, A) JP-A-4-119681 (JP, A) JP-A-64-84685 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) H01S 5/00-5/50

Claims (8)

(57) [Claims] 1. A _{Ga 1-X Al X As Ga} 1-Y1 Al Y1 first As on at least one side of the main surface of the active layer of one conductivity type
And the light guide layer, a diffraction grating in the first optical guide layer over the entire surface
The second optical guide layer and the current blocking layer of the second optical guide of the opposite conductivity type having a striped window on layer Ga _1-Z Al _Z As the Ga _1-Y2 Al _Y2 As the one conductivity type having a If, Ga _1-Y3 Al _Y3 As the one conductivity type in said stripe-shaped window
Cladding layer and is formed, and determines the AlAs mixed crystal ratio X, Y1, Y2, Y3, and Z during, Z>Y3> Y
A semiconductor laser device having a relationship of 2> X ≧ 0 and Y1> Y2. Wherein _{Ga 1-X Al X As Ga} 1-Y1 Al Y1 first As on at least one side of the main surface of the active layer of one conductivity type
A light guide layer, and one conductivity type Ga on the first light guide layer;
Ga _-Z A of the opposite conductivity type having a second light guide layer of _1-Y2 Al _Y2 As and a stripe-shaped window on the second light guide layer
and l _Z As current blocking layer, said current blocking layer
Ga _1-Y3 Al _Y3 As cladding of the protective layer and one conductivity type in said stripe-shaped window of GaAsAl having diffraction grating
And de layer is formed, and determines the AlAs mixed crystal ratio X, Y
1, Y2, Y3, and Z, Z>Y3>Y2> X
A semiconductor laser device having a relationship of ≧ 0 and Y1> Y2. 3. A one-conductivity-type GaAlAs third optical guide layer made of one-conductivity-type GaAlAs having a diffraction grating on the entire surface of the layer.
A first cladding layer of As and a G on the first cladding layer ;
an active layer of a _1-X Al X As, a first optical guide layer of Ga _1-Y1 Al _Y1 As of the opposite conductivity type on said active layer, said first light gas
The current of a second light guide layer of Ga ₁ -Y ₂ Al _Y2 As of the opposite conductivity type on the guide layer and the Ga ₁ -Z Al _Z As of one conductivity type having a striped window on the second light guide layer Block layer and
And a Ga _{1 -Y 3} Al _Y3 A of opposite conductivity type is formed in the striped window.
s and the second cladding layer is formed of, and determine the AlAs mixed crystal ratio X, Y1, Y2, Y3, and Z during, Z
>Y3>Y2> X ≧ 0, and a semiconductor laser device having a relationship of Y1> Y2. 4. The method of claim 1 Symbol active layer is a quantum well structure
The semiconductor laser device of the mounting. 5. The method according to claim 2, wherein the active layer has a quantum well structure.
The semiconductor laser device of the mounting. 6. The method of claim 3 Symbol active layer is a quantum well structure
The semiconductor laser device of the mounting. 7. Ga _1-X Al _X and the first optical guiding layer on the active layer of Ga _1-Y1 Al _Y1 As the one conductivity type of As, said first
Has a diffraction grating on the exposed surface near the end surface on the light guide layer
That a second optical guide layer of Ga _1-Y2 Al _Y2 As, of Ga _1-Z Al Z As of the opposite conductivity type having a stripe-shaped window in the second optical guide layer does not have the diffraction grating Current block layer
And the stripe-shaped window has one conductivity type Ga _{1 -Y 3} A
l _Y3 As and the cladding layers are formed of, and X determine the AlAs mixed crystal ratio, Y1, Y2, Y3, and between the Z, Z
>Y3>Y2> X ≧ 0, and a semiconductor laser device having a relationship of Y1> Y2. 8. The structure according to claim 7, wherein the active layer has a quantum well structure.
The semiconductor laser device of the mounting.