JP3582424B2 - Semiconductor laser device - Google Patents

Description

[0001]
[Industrial applications]
The present invention provides a semiconductor device comprising: a semiconductor laser device; a detector for detecting an optical output from the semiconductor laser device; and a drive circuit for driving the semiconductor laser device in accordance with the optical output detected by the detector. The present invention relates to a laser device, and more particularly, to a semiconductor laser device, a semiconductor laser package, and a method of manufacturing a semiconductor laser element capable of stabilizing the optical output of a semiconductor laser.
[0002]
[Prior art]
As a conventional semiconductor laser device, a detector for detecting the light output from the semiconductor laser element, and driving the semiconductor laser element according to the light output detected by the detector, the light output of the laser light, There is a semiconductor laser device for stabilization.
[0003]
[Problems to be solved by the invention]
In recent years, the nitride semiconductor In_xAl_yGa_1-xyHigh-brightness violet, blue, green, and other light-emitting diodes (LEDs) made of a semiconductor having an active layer containing N (x ≧ 0, y ≧ 0, x + y ≦ 1) have been commercialized, and the wavelengths of these colors have also been commercialized. It is desired to develop a laser device having an emission wavelength in the region or near ultraviolet, that is, a light emission wavelength of 300 nm to 550 nm of green emission in the near ultraviolet region.
[0004]
For example, a laser device in a wavelength range from near ultraviolet to blue, which is a short wavelength, has an advantage that the storage density of an optical recording device can be greatly increased as compared with a conventional red semiconductor laser. Further, in the silver halide photographic development technique for irradiating laser light to photographic paper for silver halide photography, a high-intensity laser device for the three primary colors of light, blue, green and red, is required.
[0005]
The present applicant has already reported that the nitride semiconductor In_xAl_yGa_1-xyA purple semiconductor laser having an active layer containing N (x ≧ 0, y ≧ 0, x + y ≦ 1) has been announced, but In is a nitride semiconductor._xAl_yGa_1-xyA semiconductor laser device having an active layer including N (x ≧ 0, y ≧ 0, x + y ≦ 1) drives the semiconductor laser element according to the optical output detected by a detector. There was variation in the light output of the laser light.
[0006]
Such a variation is a problem particularly for a technique for exposing an object having high sensitivity to light. For example, digital silver halide photographic developing technology that irradiates laser light to silver halide photographic printing paper, etc., and digital electrophotographic technology that irradiates laser light to photosensitive drums used in high-speed copiers or printers deteriorate the image. Is a serious problem. This is because, in these techniques, the amount of exposure of laser light to be exposed per unit area is finely multivalued in pursuit of higher image quality, and the influence of the variation in light output of laser light is particularly large.
[0007]
In a writable optical recording device or the like, laser light is converted into heat energy to control writing. Therefore, when the laser light source is an ultraviolet to blue laser, the spot diameter of the laser light is small and the laser light Energy also increases, so the change in thermal energy per unit area with respect to variation increases. For this reason, it is indispensable to stabilize the optical output of laser light with high accuracy even in a near ultraviolet to blue (emission wavelength: 300 nm to 460 nm) laser light source used in an optical recording device or the like.
[0008]
Accordingly, it is an object of the present invention to provide a semiconductor laser device in which the light output of laser light is extremely stable.
[0009]
[Means for Solving the Problems]
The above variation is caused by light leaking from the cladding layer of the semiconductor laser element and the light being emitted as natural light from the contact layer, causing the detector to malfunction. Part of the light generated in the active layer passes through the cladding layer and is guided by a contact layer made of a material laminated between the cladding layer and the substrate, for example, gallium nitride GaN. The light guided by the contact layer and emitted from the outer surface of the contact layer mainly causes a problem in the n-type contact layer having a large film thickness. Therefore, in order to stabilize the light output of the laser light, it is necessary to control unnecessary light from the outer surface of the n-type contact layer as much as possible.
[0010]
In order to achieve the above object, a semiconductor laser device of the present invention is configured as follows. A semiconductor laser device comprising: a semiconductor laser element; a detector for detecting an optical output from the semiconductor laser element; and a drive circuit for driving the semiconductor laser element according to the optical output detected by the detector. In the semiconductor laser device, at least an n-type contact layer, an n-type clad layer, an n-type guide layer, an active layer, a p-type guide layer, a p-type clad layer, and a p-type contact layer are sequentially formed on the same surface side of the substrate. Electrodes are formed on the p-type contact layer and the n-type contact layer.On the surface on which the electrode of the n-type contact layer is formed, and on the side of the element above the surfaceThe entire surface including the insulating film below the n-type contact layer or the n-type cladding layer is covered with a non-transmissive film made of a metal film, thereby emitting light from around the semiconductor laser device. Natural light incident on the detector is suppressed.
[0011]
With the above configuration, a malfunction of the detector due to emission of natural light from around the semiconductor laser element is prevented, so that a semiconductor laser device with extremely stable laser light output can be obtained.
[0012]
Further, when a metal film is used as the non-permeable film, a pretreatment for die bonding can be omitted.
[0013]
Furthermore, it is preferable that the metal used as the metal film contains at least one of Cr, Ti, and Pt in terms of the bonding property of die bonding. Also,The n-type contact layer preferably has a lower layer portion made of a single crystal layer grown at a higher temperature than the buffer layer, and is a layer having a lower n-type impurity concentration than the n-type contact layer or a layer not doped with n-type impurities. Preferably, there is. Further, the lower layer portion of the n-type contact layer is preferably from 0.1 μm to 20 μm.
[0014]
Further, the semiconductor laser element has a large optical output and a large natural light component._xAl_yGa_1-xyThe effect is high in the case of a semiconductor laser device having an active layer containing N (x ≧ 0, y ≧ 0, x + y ≦ 1).
[0015]
Further, the present invention is particularly effective for a semiconductor laser device that outputs ultraviolet to blue laser light in which the thermal energy per unit area varies greatly due to variations.
[0016]
A semiconductor laser device in which at least an n-type contact layer, an n-type clad layer, an n-type guide layer, an active layer, a p-type guide layer, a p-type clad layer, and a p-type contact layer are sequentially stacked on a substrate, wherein n So that the entire outer surface above the mold guide layer is coveredOn a fixed base with an adhesive sheet or depression formedA method of manufacturing a semiconductor laser device in which a fixed and non-transmissive film is formed, thereby significantly changing a conventional semiconductor laser device capable of being used in a semiconductor laser device having extremely stable light output of laser light. Can be provided without.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0018]
FIG. 1 shows a conceptual diagram of a semiconductor laser device. The semiconductor laser device includes, for example, a laser package 10 including a semiconductor laser element 1 and a photodiode 2 as an example of a detector, an output signal supply unit 3 functioning as a drive circuit, a bias supply unit 4, and an optical output detection unit 5. Is done. Here, as described later, the entire surface of the semiconductor laser device 1 below the n-type cladding layer 103 is covered with the non-transmissive film 133. Further, the entire outer surface below the n-type contact layer 102 may be covered with the non-transmissive film 133.
[0019]
A part of the laser light output from the semiconductor laser device 1 is converted into a current by the photodiode 2. The light detection unit 5 detects the light output of the laser light from the current converted by the photodiode 2 and adjusts the bias to be supplied so that the light output of the laser light from the semiconductor laser element 1 is stabilized according to the detection result. And outputs a signal to the bias supply unit 4. The bias supply unit 4 applies a bias to the semiconductor laser device 1 based on a signal input from the light detection unit 5. The output signal supply unit 3 drives the semiconductor laser device 1 according to an input signal, for example, by turning on / off.
[0020]
In the above configuration, the bias applied to the semiconductor laser element 1 by the bias supply unit 4 is controlled to stabilize the optical output of the laser light from the semiconductor laser element 1. The stabilization can also be achieved by directly supplying a drive bias from the output signal supply unit 3 to the semiconductor laser device 1 and controlling the same. Further, in a laser device used in digital silver halide photographic development technology, digital electrophotography technology, or the like, which controls the light output of the laser light by multi-leveling, the laser package 10 of the present invention has a light output of the laser light. Since it is extremely stable, it is possible to set the variation of the light output of the laser light within the difference of the light output of the laser light per one gradation, which is particularly effective. Also, when the laser light source used in a writable optical recording device is an ultraviolet to blue laser, the spot diameter of the laser light is small and the energy of the laser light is also high, so that the thermal energy change per unit area due to the variation. Therefore, it is indispensable to stabilize the optical output of the laser beam with high accuracy. Therefore, the present invention is particularly effective for ultraviolet to blue lasers.
[0021]
Next, FIG. 2 shows, as an example, a schematic view of a cross section taken along a plane parallel to the resonance plane of the semiconductor laser device 1. The semiconductor laser device 1 includes an n-type contact layer 102, an n-type cladding layer 103, an n-type guide layer 104, an active layer 105, a p-type guide layer 106, a p-type clad layer 107, and a p-type contact layer 108 on a substrate 101. Are sequentially stacked, and further, electrodes are formed on the n-type contact layer 102 and the p-type contact layer 108, respectively. An insulating film 131 is coated on the entire outer surface of the n-type contact layer 102 from above the surface on which the electrodes are formed, and further from below the entire surface of the outer surface in the direction of the substrate 101 below the n-type cladding layer 103. Is coated with a non-permeable film 133.
[0022]
The laser light, which is generated by natural light emission, is reflected / reciprocated within the active layer 105 and the guide layer 104 and amplified, and is emitted out of the resonance surface as stimulated emission light. Here, when the light is amplified and guided in the active layer 105, some light is scattered and guided in layers other than the active layer 105 and the guide layers 104 and 106. In order to prevent such light scattering and improve luminous efficiency, the semiconductor laser device 1 has a light confinement layer (cladding layer) and a layer for confining light generated and guided in the active layer 105. The n-side and the p-side are provided so as to sandwich the active layer 105. The cladding layer is designed such that the material constituting the layer has a smaller optical refractive index than that of the material of the active layer 105, thereby exhibiting the effect of confining light.
[0023]
However, some of the scattered light passes through the cladding layer and enters the contact layer. The contact layer is made of a material having a relatively large refractive index, is reflected by the cladding layer or the surface of the sapphire substrate 101, and is emitted from the outer surface of the contact layer. Then, the natural light guided by the contact layer and emitted from the outer surface affects a single spot of the laser light emitted from the semiconductor laser device 1. The effect of the natural light from the contact layer is greater in the semiconductor laser package 10 in which the photodiode 2 that converts a part of the light output of the laser light output from the semiconductor laser element 1 into a current is arranged in the vicinity. In order to suppress the influence of natural light emitted from the outer surface of the contact layer on the photodiode 2, a non-transmissive film 133 is coated. The non-transmissive film 133 is formed on the entire outer surface below the n-type cladding layer 103, that is, on the resonance surface, the side surface, and the bottom surface below the n-type cladding layer 103 so as to minimize the influence of natural light on the photodiode 2. The surface of the semiconductor laser element 1 facing the outside is coated. The same function can be achieved even when the surface coated with the non-transmissive film 133 is the entire surface below the n-type contact layer 102. Not limited to the above, the surface coated with the non-permeable film 133 may be at least the entire surface below the n-type contact layer 102.
[0024]
FIG. 3 shows, as an example, a schematic view of a cross section viewed from the side surface of the semiconductor laser device 1, that is, a cross section taken along a plane parallel to the resonance direction and perpendicular to the substrate 101. A reflection film 132 is formed on the resonance surface. FIG. 3 shows an example in which the reflection film 132 is formed on the entire surface of the resonance surface at both ends. However, the reflection film 132 may be formed on one of the resonance surfaces or on the active layer 105 on the resonance surface. The reflection film 132 is preferably formed in contact with the outer surface of the semiconductor laser device 1, and when formed in contact, the reflection film 132 of an insulator is preferable. The formation of the reflective film 132 is preferable because the resonator loss is small, reflection / reciprocation for amplifying light in the active layer 105 occurs favorably, and luminous efficiency is improved.
[0025]
An embodiment of the semiconductor laser device 1 will be described below.
[0026]
The substrate 101 includes sapphire having a C-plane as a main surface, sapphire having an R-plane and an A-plane as a main surface, and spinel (MgA1).₂O₄), A semiconductor substrate 101 such as SiC (including 6H, 4H, and 3C), ZnS, ZnO, GaAs, and GaN can be used.
[0027]
A buffer layer of, for example, AlN, GaN, AlGaN, InGaN, etc. may be provided between the substrate 101 and the n-type contact layer 102. The buffer layer is grown at a temperature of 900 ° C. or less, and is formed with a film thickness of several tens to several hundreds of mm. This buffer layer is formed between the substrate 101 and the nitride semiconductor (In_xAl_yGa_1-xyN, x ≧ 0, y ≧ 0, x + y ≦ 1) are formed to alleviate the irregular lattice constant.
[0028]
N-type contact layer 102 is made of a nitride semiconductor doped with an n-type impurity, and is desirably adjusted to 0.2 μm or more and 4 μm or less. The range of the n-type impurity doped into the nitride semiconductor of this n-type contact layer 102 is 1 × 10¹⁷/ Cm³~ 1 × 10²¹/ Cm³Is adjusted to the range. Further, the lower part of the n-type contact layer 102 may be formed of a layer made of a single crystal nitride semiconductor grown at a higher temperature than the buffer layer. When the lower layer portion of the n-type contact layer 102 is a layer having a lower n-type impurity concentration than the n-type contact layer 102 or a nitride semiconductor layer not doped with the n-type impurity, preferably a GaN layer, The crystallinity of the layer composed of the nitride semiconductor doped with is improved.
[0029]
It is desirable that the thickness of the lower layer portion of the n-type contact layer 102 be adjusted to 0.1 μm or more, more preferably 0.5 μm or more, and most preferably 1 μm or more and 20 μm or less. If the lower layer portion of the n-type contact layer 102 is thinner than 0.1 μm, the n-type contact layer 102 having a high impurity concentration must be grown thick, and the improvement in the crystallinity of the n-type contact layer 102 tends not to be expected much. is there. If the thickness is more than 20 μm, crystal defects tend to increase in the lower layer portion of the n-type contact layer 102 itself. Further, as an advantage of growing the lower layer portion of the n-type contact layer 102 thickly, there is an improvement in heat dissipation. That is, when the semiconductor laser device 1 is manufactured, heat is easily spread in the lower layer portion of the n-type contact layer 102, and the life of the semiconductor laser device 1 is improved.
[0030]
The n-type contact layer 102 is a layer that achieves ohmic contact with the n-electrode 121. Examples of the material of the n-type electrode that can obtain a preferable ohmic with the n-type nitride semiconductor include metals or alloys such as Al, Ti, W, Si, Zn, Sn, and In. When the n-type contact layer 102 uses a conductive substrate 101 such as GaN, SiC, or ZnO as the substrate 101 and provides a negative electrode on the back surface of the substrate 101, the lattice constant mismatch between the substrate 101 and the nitride semiconductor is provided. Acts as a layer that alleviates the
[0031]
A crack preventing layer may be provided between the n-type contact layer 102 and the n-type cladding layer 103. This crack preventing layer is made of, for example, 5 × 10¹⁸/ Cm³Doped In_0.1Ga_0.9It is made of N and has a thickness of, for example, 500 °.
[0032]
The n-type cladding layer 103 functions as a carrier confinement layer and a light confinement layer. The n-type cladding layer 103 is made of, for example, Si¹⁸/ Cm³Doped n-type Al_0.2Ga_0.8A superlattice layer in which a layer made of N and having a thickness of 20 ° and a second layer made of non-doped GaN and having a thickness of 20 ° are alternately laminated, and a total thickness of, for example, 0.5 μm Having. Although this n-type cladding layer 103 can be grown from a single nitride semiconductor, a superlattice layer can form a carrier confinement layer with good crystallinity without cracks.
[0033]
The n-type guide layer 104 is designed so that the light refractive index of the material constituting the n-type guide layer is substantially the same as that of the active layer, and acts as a layer that guides light together with the active layer. The n-type guide layer 104 is preferably formed by growing GaN or InGaN, and is preferably grown to a thickness of usually 100 to 5 μm, more preferably 200 to 1 μm. Note that this n-type guide layer can also be a superlattice layer.
[0034]
The active layer 105 is made of, for example, 8 × 10¹⁸/ Cm³In doped with_0.2Ga_0.8A well layer made of N and having a thickness of 25 °¹⁸/ Cm³Doped In_0.05Ga_0.95A multi-quantum well structure (MQW) having a predetermined thickness is formed by alternately stacking barrier layers having a thickness of 50 ° made of N.
[0035]
Further, a p-type cap layer may be provided between the active layer 105 and the p-type guide layer 106. The p-type cap layer is made of, for example, Mg of 1 × 10²⁰/ Cm³Doped p-type Al_0.3Ga_0.7N, for example, having a thickness of 200 °.
[0036]
The p-type guide layer 106 is made of, for example, non-doped GaN or InGaN, and has a thickness of 0.1 μm. The p-type guide layer 106 functions as a light guide layer of the active layer 105, like the n-type guide layer. This layer also functions as a buffer layer when growing the p-type cladding layer 107, and functions as a preferable guide layer by growing with a thickness of 100 to 5 μm, more preferably 200 to 1 μm. The p-type light guide layer may be of a p-type conductivity type by doping a p-type impurity such as Mg.
[0037]
The p-type cladding layer 107 is made of, for example, Mg²⁰/ Cm³Doped p-type Al_0.2Ga_0.8A layer made of N and having a thickness of 20 °;²⁰/ Cm³A superlattice layer is formed by alternately stacking layers having a thickness of 20 ° made of doped p-type GaN. The p-type cladding layer 107 functions as a carrier confinement layer similarly to the n-type cladding layer 103, and particularly functions as a layer for lowering the resistivity of the p-type layer. Although the thickness of the p-type cladding layer 107 is not particularly limited, it is preferable that the thickness is 100 ° or more and 2 μm or less, more preferably 500 ° or more and 1 μm or less.
[0038]
The p-type contact layer 108 is, for example, Mg²⁰/ Cm³It is made of doped p-type GaN and has a thickness of, for example, 150 °. This p-type contact layer 108 is made of p-type In_xAl_yGa_1-xyN (x ≧ 0, y ≧ 0, x + y ≦ 1), and preferably, the most preferable ohmic contact with the p electrode 123 is obtained by using Mg-doped GaN as described above.
[0039]
As p electrode 123, for example, Ni, Pd, Ni / Au is used. Here, Ni / Au is a laminate or alloy of Ni and Au.
[0040]
As the insulating film 131, for example, SiO₂Is used.
[0041]
The non-transmissive film 133 is a film that does not transmit light, such as absorbing light or reflecting light. The non-transmissive film 133 that can be used in the present invention is, for example, a light absorbing film, a metal film, or the like. The film thickness is 50 ° or more, preferably 500 to 2000 °. Specific examples of the non-transmissive film 133 include, for example, a light absorbing film such as TiO and SiO or a metal film such as Cr, Ti / Pt, Ti, Ni, Al, and Ag. The non-transmissive film 133 may be formed in contact with the resonance surface of the nitride semiconductor, or may be formed on the insulator film after forming an insulator film (for example, the reflective film 132 of the insulator). . Furthermore, when the non-transmissive film 133 is a metal film, the pretreatment of die bonding can be omitted. Further, it is preferable to use Cr, Ti / Pt, Ti, or the like as the metal film from the viewpoint of die bonding.
[0042]
The reflective film 132 that can be used in the present invention includes, for example, a dielectric multilayer film, and specific examples thereof include the following.
[0043]
The dielectric multilayer film is basically formed by alternately laminating inorganic materials having different reflectances from each other. For example, by alternately laminating the inorganic materials with a thickness of λ / 4n (λ: wavelength, n: refractive index), the reflectance is increased. Can be changed. The type, thickness, and the like of each thin film of the dielectric multilayer film can be designed by appropriately selecting their inorganic materials according to the wavelength of the semiconductor laser device 1 to be oscillated. For example, the inorganic material includes TiO as a thin film material on the high refractive index side.₂, ZrO₂, HfO₂, Sc₂O₃, Y₂O₃, MgO, Al₂O₃, Si₃N₄, ThO₂At least one of them can be selected, and SiO 2 is used as the thin film material on the low refractive index side.₂, ThF₄, LaF₃, MgF₂, LiF, NaF, Na₃AlF₆At least one of them can be selected, and these high-refractive-index side thin-film materials and low-refractive-index side thin-film materials are appropriately combined, and several layers having a thickness of several tens to several micrometers depending on the wavelength of oscillation. By stacking up to several tens of layers, a dielectric multilayer film can be formed.
[0044]
Further, in the case of the semiconductor laser device 1 which oscillates from near ultraviolet to blue with a nitride semiconductor, the dielectric multilayer film formed on the optical resonance surface is preferably made of SiO 2.₂, TiO₂, ZrO₂At least two or more types selected from among them are most suitable. This is because the three kinds of oxides have low light absorption in the range of 360 nm to 460 nm, and do not peel off very well with the nitride semiconductor. Further, even if the light of the above-mentioned wavelength is continuously irradiated for a long time, there is no deterioration, and more preferably, the semiconductor laser element 1 is extremely excellent in heat resistance against heat generation. The dielectric multilayer film can be formed using, for example, a vapor deposition technique such as vapor deposition or sputtering.
[0045]
By configuring the laser element in this manner, laser oscillation with a violet emission wavelength of 400 nm was obtained at room temperature. Each layer of the active layer 105 is not limited to these, but may be In._xAl_yGa_1-xyN (x ≧ 0, y ≧ 0, x + y ≦ 1). By appropriately selecting the mixed crystal ratio of x and y, a green emission wavelength of 550 nm to a green emission wavelength of 300 nm can be selected. The composition of the well layer is In_xGa_1-xA ternary mixed crystal of N (0 ≦ x ≦ 1) is preferable in terms of crystallinity. Here, the nitride semiconductor In_xAl_yGa_1-xyThe emission wavelength of N (x ≧ 0, y ≧ 0, x + y ≦ 1) has been described for the near ultraviolet emission wavelength of 300 nm to the green emission wavelength of 550 nm. Is also applicable.
[0046]
Next, FIG. 4 shows a schematic view of a method of forming the non-permeable film 133. On a substrate 101, an n-type contact layer 102, an n-type clad layer 103, an n-type guide layer 104, an active layer 105, a p-type guide layer 106, a p-type clad layer 107, and a p-type contact layer 108 are sequentially stacked. An electrode is formed on each of the mold contact layer 102 and the p-type contact layer 108, and the semiconductor laser device 1 coated with the insulating film 131 is placed on an adhesive sheet 7 that can be held in a vacuum on the upper surface of the semiconductor laser device 1 (in this case, (Electrode surface) facing the sheet surface. Then, for example, TiO is formed as a non-transmissive film 133 below the n-type cladding layer 103, that is, on the entire outer surface in the direction of the substrate 101 by sputtering. Then, it is set in a sputtering apparatus, and for example, TiO is formed as a non-transmissive film 133 below the n-type cladding layer 103, that is, on the entire outer surface in the direction of the substrate 101 by sputtering. Further, instead of the adhesive sheet 7, the semiconductor laser element 1 may be fixed to a fixing base having a recess formed in accordance with the shape above the n-type guide layer 104 of the semiconductor laser element 1, and sputtering may be performed in the same manner. An evaporation method may be used as a film formation method.
[0047]
FIG. 5 shows a perspective view of the semiconductor laser package 10. A cover 13 having a window 14 is mounted on the flange 11, and the semiconductor laser device 1 and the photodiode 2 are installed inside the cover 13. The lead 15 is a terminal for inputting and outputting a bias for driving the semiconductor laser device 1 and a voltage of the photodiode 2.
[0048]
FIG. 6 shows a schematic sectional view of the semiconductor laser package 10. A stay 12 is mounted on the flange 11, and the semiconductor laser element 11 is die-bonded to the stay 12 with a solder material such as Au / Sn or Au / Si. Here, the substrate 101 of the semiconductor laser device 1 made of sapphire or the like and Au / Sn or Au / Si have poor binding properties. A metal such as Cr, Ti / Pt, or Ti, which has good binding properties on both sides, is used as a back metal on the bottom surface of the substrate 101. Therefore, by using a metal such as Cr, Ti / Pt, or Ti for the non-transmissive film 133, the pretreatment for die bonding can be omitted. Further, it is more preferable to form an Au film thereon in view of the binding property with Au / Sn and Au / Si.
[0049]
【The invention's effect】
By preventing the detector from malfunctioning due to the emission of natural light from around the semiconductor laser element 1, a semiconductor laser device with extremely stable laser light output can be obtained. In particular, In which emits light from ultraviolet to blue_xAl_yGa_1-xyFor an N (x ≧ 0, y ≧ 0, x + y ≦ 1) based semiconductor, the natural light component occupies a large proportion in the laser beam component due to the characteristics of the material, which is more effective.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of a semiconductor laser device according to the present invention.
FIG. 2 is a schematic cross-sectional view taken along a plane parallel to a resonance plane of the semiconductor laser device 1 according to the present invention.
FIG. 3 is a schematic cross-sectional view of the semiconductor laser device 1 according to the present invention as viewed from a side.
FIG. 4 is a schematic diagram of a method for forming a non-transmissive film 133 on the semiconductor laser device 1 according to the present invention.
FIG. 5 is a perspective view of a semiconductor laser package 10 according to the present invention.
FIG. 6 is a schematic view of a cross section of a semiconductor laser package 10 according to the present invention.
[Explanation of symbols]
1 ... Semiconductor laser device
2. Photodiode
3. Output signal supply unit
4 Bias supply unit
5 ... light output detector
7 ... Adhesive sheet
10. Semiconductor laser package
11 Flange
12. Stay
13. Cover
14. Windu
15 ··· Lead
101 substrate
102... N-type contact layer
103 ... n-type cladding layer
104... N-type guide layer
105 ··· Active layer
106 p-type guide layer
107 p-type cladding layer
108 p-type contact layer
121... N electrode
123 ···· p electrode
131 ··· Insulating film
132 ··· Reflection film
133 ... non-permeable membrane

Claims (5)

A semiconductor laser device comprising: a semiconductor laser element; a detector for detecting an optical output from the semiconductor laser element; and a drive circuit for driving the semiconductor laser element according to the optical output detected by the detector. hand,
In the semiconductor laser device, at least an n-type contact layer, an n-type clad layer, an n-type guide layer, an active layer, a p-type guide layer, a p-type clad layer, and a p-type contact layer are sequentially stacked on the same side of a substrate. An electrode is formed on the p-type contact layer and the n-type contact layer,
An insulating film is formed on the entire resonance surface of the semiconductor laser device, and on the surface on which the electrode of the n-type contact layer is formed and on the side surface of the device above the surface ,
By covering the entire outer surface including the insulating film below the n-type contact layer or the n-type cladding layer with a non-transmissive film made of a metal film, natural light emitted from around the semiconductor laser device is transmitted to the detector. A semiconductor laser device wherein incidence is suppressed. 2. The semiconductor laser device according to claim 1, wherein the metal used as the metal film includes at least one of Cr, Ti, and Pt. A buffer layer grown at 900 ° C. or less is formed between the substrate and the n-type contact layer, and the n-type contact layer is a lower layer made of a single crystal layer grown at a higher temperature than the buffer layer. 2. The semiconductor laser device according to claim 1, comprising: 4. The semiconductor laser device according to claim 3, wherein the lower layer portion of the n-type contact layer is a layer having a lower n-type impurity concentration than the n-type contact layer or a layer not doped with the n-type impurity. 4. The semiconductor laser device according to claim 3, wherein a lower layer portion of the n-type contact layer has a thickness of 0.1 μm or more and 20 μm or less.

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