JP2004055692A - Semiconductor optical apparatus, semiconductor laser module, and optical fiber amplifier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a highly reliable semiconductor optical apparatus where light output does not stop suddenly. <P>SOLUTION: The semiconductor optical apparatus comprises a submount 1; a semiconductor laser element 2; and an alloy layer arranged between the submount 1 and a semiconductor laser element 2. The alloy layer 3 is formed by one portion of the electrode of the semiconductor laser element 2 and a solder layer provided on the submount 1, in advance, and the content of Sn contained in the alloy layer 3 is to be 26 wt.% or lower. By reducing the content of Sn, the concentration of Sn to a laser light-emitting region in operation can be restrained, thus preventing laser oscillation from stopping. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a semiconductor optical device having a semiconductor optical element fixed on a submount, and particularly to a semiconductor optical device, a semiconductor laser module, and an optical fiber amplifier having high reliability, in which laser oscillation does not suddenly stop. About.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a semiconductor optical element such as a semiconductor laser element is used in a state of being fixed on a submount in order to efficiently release heat generated at the time of light emission to the outside. The submount is formed of a material having excellent heat conductivity, and has a function of receiving heat generated at the time of light emission through a contact surface with the semiconductor optical element and releasing the heat to the outside.
[0003]
In order to fix the semiconductor optical element to the submount, usually, a method of arranging a solder layer made of a solder material on the upper surface of the submount in advance and fixing the semiconductor optical element on the submount by such a solder layer is used. Can be Specifically, in a state where the semiconductor optical element is arranged on the upper surface of the submount, pressure is applied to the semiconductor optical element, and the whole is heated by a heater to bring the solder layer into a flowing state. Thereafter, the semiconductor optical element is fixed on the submount by lowering the temperature and curing the solder layer again.
[0004]
With the structure in which the semiconductor optical element is fixed to the submount via the solder layer, the adhesion between the semiconductor optical element and the submount is enhanced, and heat can be more efficiently released to the outside. Further, since the semiconductor optical element usually has a structure in which an electrode is formed on a surface fixed to a submount, using a conductive solder layer also has an advantage that the electrode can be easily taken out.
[0005]
[Problems to be solved by the invention]
However, a new problem arises when the semiconductor optical element is used while being fixed on the submount via the solder layer. When a semiconductor optical element is used in such a state, for example, in a semiconductor laser element, it is known that, although rare, laser oscillation suddenly stops.
[0006]
FIG. 13 shows a change in an injection current value of a semiconductor laser device in which oscillation is stopped as a result of performing an acceleration test on a semiconductor laser device having a structure in which a semiconductor laser device is fixed on a submount with a general solder layer interposed. It is a schematic graph. In such an acceleration test, a change in the injection current value while maintaining the light output at 500 mW under a temperature condition of 70 ° C. is examined. As shown in FIG. 13, the pattern in which laser oscillation stops is a pattern in which laser oscillation stops suddenly (hereinafter referred to as “sudden deterioration”) despite good current characteristics until immediately before the oscillation stops. There are two patterns (hereinafter, referred to as “rapid deterioration”) in which laser oscillation stops after the current value tends to increase.
[0007]
Of the oscillation stop patterns, the stop of laser oscillation due to sudden deterioration is mainly caused by COMD (Catastrophic Optical Mirror Damage: cavity facet destruction). COMD is a phenomenon caused by heat generated in the vicinity of an end face of a semiconductor laser element. Such sudden deterioration is a phenomenon that can occur even when a single semiconductor laser element is used.
[0008]
On the other hand, the stoppage of laser oscillation due to rapid deterioration is not reproduced when the semiconductor laser device alone is subjected to an acceleration test, and is also reproduced when the semiconductor laser device is fixed on the submount without using a solder layer. Never. Therefore, it is presumed that the oscillation stop due to the rapid deterioration is caused by the presence of the solder layer. To prevent the laser oscillation from stopping due to the rapid deterioration, it is necessary to optimize the material of the solder layer.
[0009]
The present invention has been made in view of the above-mentioned drawbacks of the related art, and has as its object to provide a highly reliable semiconductor optical device in which laser oscillation does not suddenly stop.
[0010]
[Means for Solving the Problems]
To achieve the above object, a semiconductor optical device according to claim 1, comprising a base and a semiconductor optical element fixed on the base, wherein the base and the semiconductor optical device are provided. An alloy layer having a Sn content of 26% by weight or less is provided between the device and the element.
[0011]
According to the first aspect of the present invention, since the Sn content in the alloy layer is set to 26% by weight or less, it is possible to suppress Sn from aggregating in the light emitting region of the semiconductor optical element, and to cause laser oscillation due to rapid deterioration. Semiconductor optical device in which the stoppage of the semiconductor optical device is prevented can be realized.
[0012]
Further, in the semiconductor optical device according to claim 2, in the above invention, the alloy layer is a solder layer disposed on the base and a metal disposed on the lower surface of the semiconductor optical element and in contact with the solder layer. It is characterized by being formed by at least a part of an electrode.
[0013]
Further, in the semiconductor optical device according to claim 3, in the above invention, the metal electrode has a multilayer structure in which a plurality of metal materials are sequentially arranged, and the alloy layer includes the solder layer and the multilayer structure. And a layer in contact with the solder layer.
[0014]
According to a fourth aspect of the present invention, in the above-mentioned invention, the layer in contact with the solder layer in the multilayer structure contains Au.
[0015]
According to a fifth aspect of the present invention, in the above-mentioned semiconductor optical device, the solder layer contains Au and Sn.
[0016]
According to a sixth aspect of the present invention, in the above-described semiconductor optical device, the solder layer contains two kinds of metals selected from Pb, Cd, and Ag, and Sn.
[0017]
According to a seventh aspect of the present invention, in the semiconductor optical device described above, the solder layer is formed of Ge or Si, Au, and unavoidable impurities.
[0018]
The semiconductor optical device according to claim 8 is characterized in that, in the above invention, the solder layer is formed of Ag or In, Pb, and unavoidable impurities.
[0019]
According to a ninth aspect of the present invention, in the above-mentioned invention, the solder layer is formed of Ag or Zn, Cd, and unavoidable impurities.
[0020]
According to a tenth aspect of the present invention, in the above-mentioned invention, the solder layer is formed of Al or Ag, Zn, and unavoidable impurities.
[0021]
The semiconductor optical device according to claim 11 is characterized in that, in the above invention, the solder layer is formed of Cu or Te, Zn, Al, and unavoidable impurities.
[0022]
According to a twelfth aspect of the present invention, in the above-mentioned invention, the solder layer is formed of In, Ag, and unavoidable impurities.
[0023]
A semiconductor optical device according to a thirteenth aspect is characterized in that, in the above invention, the semiconductor optical element is a semiconductor laser element.
[0024]
According to a fourteenth aspect of the present invention, there is provided a semiconductor laser module, the semiconductor optical device according to the thirteenth aspect, a transmission path for guiding laser light emitted from the semiconductor optical device to the outside, the semiconductor optical device, and the transmission device. And an optical coupling lens system for optically coupling the optical path with the path.
[0025]
The semiconductor laser module according to claim 15 is the semiconductor laser module according to the above invention, further comprising: a photodetector that measures an optical output of the semiconductor optical device; a temperature control module that controls a temperature of the semiconductor optical device; and an isolator. It is characterized by having.
[0026]
Further, an optical fiber amplifier according to claim 16 is a pump light source provided with the semiconductor optical device according to claim 13 or the semiconductor laser module according to claim 14 or 15, an amplification optical fiber, and the pump light source. And a coupler for optically coupling the amplification optical fiber.
[0027]
The optical fiber amplifier according to claim 17 is characterized in that, in the above invention, the amplification optical fiber is doped with erbium.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of a semiconductor optical device, a semiconductor laser module, and an optical fiber amplifier according to the present invention will be described with reference to the drawings. In the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and are different from actual ones. In addition, it is needless to say that dimensional relationships and ratios are different between the drawings.
[0029]
(Embodiment 1)
First, a semiconductor laser device according to the first embodiment will be described. FIG. 1 is a diagram illustrating the structure of the semiconductor laser device according to the first embodiment. The semiconductor laser device according to the first embodiment has a structure including a submount 1, a semiconductor laser element 2, and an alloy layer 3 disposed between the submount 1 and the semiconductor laser element 2.
[0030]
The submount 1 emits heat generated when the semiconductor laser element 2 performs laser oscillation to the outside. Specifically, the submount 1 is formed of a material having excellent thermal conductivity such as CuW, and has a function of releasing heat generated from the semiconductor laser element 2 to the outside.
[0031]
The semiconductor laser device 2 has a structure in which a first electrode 4 is disposed on a lower surface and a second electrode 5 is disposed on an upper surface. Further, the semiconductor laser element 2 has at least an active layer 6 inside, and has a structure in which a laser is oscillated by injecting a current between the first electrode 4 and the second electrode 5. The semiconductor laser device 2 used in the first embodiment includes, for example, a homojunction laser, a double heterojunction laser (DH laser), a DH stripe laser, a buried hetero laser (BH laser), a ridge laser, and a SAS ( It is possible to adopt a structure such as a Self Alignment Structure (self-aligned structure) type laser, a DCH (Decoupled Configuration Heterostructure) type laser, or the like. Also, as the semiconductor material forming the semiconductor laser element 2, it is possible to use GaAs-based, InP-based, AlGaAs-based, GaN-based, and the like.
[0032]
The first electrode 4 has a multilayer structure including a plurality of metal layers. More specifically, as shown in FIG. 2A, the structure has a first metal layer 8, a second metal layer 9, and a third metal layer 10 each containing a different metal as a main component. In the first embodiment, the third metal layer 10 contains Au as a main component.
[0033]
As shown in FIGS. 2A and 2B, the alloy layer 3 includes a third metal layer 10 that is a part of the first electrode 4 and a solder layer 11 that is disposed on the submount 1. It is formed by alloying. The solder layer 11 is formed of a solder material containing Sn and Au as main components. Since the third metal layer 10 contains Au as a main component as described above, the alloy layer 3 is made of Sn. , Au as a main component. The Sn content in the alloy layer 3 is 26% by weight or less.
[0034]
The manner in which the alloy layer 3 is formed will be described. The semiconductor laser device 2 is configured such that a desired semiconductor layer is laminated on a semiconductor substrate by a CVD (Chemical Vapor Deposition) apparatus or the like, and then the second electrode 5 and the second electrode 5 each having a multilayer structure are formed on the back surface of the semiconductor substrate and the surface opposed thereto. It is completed with one electrode 4 arranged. On the other hand, a solder layer 11 is applied on the upper surface of the submount 1.
[0035]
Then, the semiconductor laser element 2 is arranged on the submount 1 so that the solder layer 11 and the third metal layer 10 constituting the second electrode 5 are in contact with each other, and the whole is heated by a heater or the like under a predetermined pressure. Heat. Such heating causes the solder layer 11 to melt, causing alloying with the third metal layer 10 in contact with the solder layer 11, and as shown in FIG. 2B, the alloy layer 3 between the submount 1 and the semiconductor laser element 2. Is formed.
[0036]
The reason why the content of Sn in the alloy layer 3 is set to 26% by weight or less in the semiconductor laser device according to the first embodiment will be described below. As described above, when a semiconductor laser device is fixed on a submount to perform laser oscillation, in a semiconductor laser device having a conventional structure, oscillation stop due to rapid deterioration as shown by a curve in FIG. It was. Observation of the SEM image of the emission side end face of the semiconductor laser device in which laser oscillation was stopped due to rapid deterioration showed that particles were aggregated in the vicinity of the laser light emission region as shown in FIG. Since such a phenomenon is characteristically observed in a rapidly deteriorated semiconductor laser device, it is presumed that aggregation of particles causes rapid deterioration.
[0037]
In order to examine the agglomerated particles, the composition of elements present in the respective regions shown in FIG. 4 on the emission-side end face of the rapidly deteriorated semiconductor laser device was examined by Auger analysis. Here, the first region 12 is a part of the laser light emission region where the particles are aggregated, and the second region 13 is a region on the emission side end face of the semiconductor laser element and near the alloy layer. Further, the third region 14 is a region on the surface of the alloy layer and is a region near the second region 13, and the fourth region 15 is a region on the surface of the alloy layer that is not particularly changed in the SEM image. FIGS. 5 to 8 show graphs of the results of the Auger analysis. FIG. 5 is a graph showing the result of the Auger analysis of the first region 12. FIGS. 6, 7, and 8 show the Auger analysis of the second region 13, the third region 14, and the fourth region 15 in this order. 6 is a graph showing the results of the above.
[0038]
As shown in FIG. 5, in the first region 12 which is a part of the laser light emission region, C was 8.9 mol%, Sn was 29.0 mol%, and O was 52.0 mol%. As shown in FIG. 6, in the second region 13, C is 12.2 mol%, Sn is 26.1 mol%, O is 43.9 mol%, Ga is 2.8 mol%, and Si is 14.9 mol%. Thus, only a trace amount of Au was observed. Further, as shown in FIG. 7, in the third region 14, C is 11.2 mol%, Sn is 24.8 mol%, O is 44.9 mol%, Ge is 7.3 mol%, and Au is 11.8 mol%. there were. Further, as shown in FIG. 8, in the fourth region 15 where no change is particularly observed in the SEM image, C is 11.8 mol%, Sn is 20.0 mol%, O is 42.2 mol%, and Ga is 10.9 mol%. % And Au were 15.2 mol%.
[0039]
Since the semiconductor laser device has a structure that does not contain Sn, Sn should originally be contained only in the alloy layer. However, the results of Auger analysis shown in FIGS. 5 and 6 show that the ratios of Sn in the first region 12 and the second region 13 are very high, 29.1 mol% and 26.1 mol%, respectively. In addition, the third region 14 and the fourth region 15 belonging to the same alloy layer also have a higher Sn ratio in the third region 14 near the second region 13 than in the fourth region 15 where no change is observed. Is shown. In view of this fact, it can be inferred that in the rapidly deteriorated semiconductor laser device, Sn contained in the alloy layer causes migration for some reason. Then, it is considered that a large amount of Sn particles aggregate in the light emission region, causing rapid deterioration and stopping laser oscillation.
[0040]
In order to confirm this fact, element analysis in the stacking direction including the laser light emitting region after rapid deterioration was performed on a semiconductor laser device different from that in FIG. In such a semiconductor laser device, no particular change was observed in the vicinity of the alloy layer in observation by SEM, but aggregation of particles was observed in the laser light emission region, as in the case of FIG. FIG. 9 is a graph showing the distribution of Au in the stacking direction with respect to the emission-side end face of the semiconductor laser device, and FIG. 10 is a graph showing the distribution of Sn in the stacking direction. As shown in FIG. 9, Au contained in the alloy layer hardly exists on the end face of the semiconductor laser device including the laser beam emission region, but as shown in FIG. 10, it is contained in the alloy layer similarly to Au. It is shown that a certain amount of Sn exists at a position corresponding to the laser beam emission region. Of the metal materials forming the solder layer, Au does not agglomerate in the laser light emission region, and only Sn agglomerates in the laser light emission region. It can be concluded that this occurs when having an alloy layer containing.
[0041]
From this conclusion, in the semiconductor laser device according to the first embodiment, the Sn content in the alloy layer 3 is set to a certain amount or less. In particular, by forming the solder layer 11 and the third metal layer 10 shown in FIG. 2A so that the Sn content in the alloy layer 3 is 26% by weight or less, Sn is aggregated in the laser light emitting region. Can be effectively suppressed, and the stoppage of laser oscillation due to rapid deterioration can be suppressed.
[0042]
In the first embodiment, the solder layer 11 is mainly composed of Sn and Au. However, the solder layer 11 may be formed of a ternary element such as Sn-Pb-Cd, Sn-Pb-Ag, or Sn-Cd-Ag. It may contain a system solder material and unavoidable impurities. Even when such a solder material is used, in the alloy layer formed with a part of the metal electrode, the structure in which the Sn content is suppressed to 26% by weight or less prevents oscillation stoppage due to rapid deterioration. be able to.
[0043]
It is also effective to form the solder layer 11 with a solder material containing no Sn. Examples of the solder material not containing Sn include Au-Ge, Au-Si, Pb-Ag, Pb-In, Cd-Ag, Cd-Zn, Zn-Al, Zn-Ag, Zn-Al-Cu, Zn -Al-Te, In-Ag and the like. When the solder layer 11 is formed of a solder material containing no Sn and unavoidable impurities, the Sn content in the alloy layer 3 is 0% by weight, so that Sn does not aggregate on the laser light emitting region. Laser oscillation stoppage due to rapid deterioration can be suppressed. It is needless to say that if the inevitable impurities and the like can be completely removed, it is not necessary to include the inevitable impurities and the like in the solder layer 11.
[0044]
Further, for the third metal layer 10 forming the first electrode 4, a metal material other than Au may be used. Further, the first electrode 4 may have a multilayer structure other than the three-layer structure of the first metal layer 8, the second metal layer 9, and the third metal layer 10, and the first electrode may be formed by a single metal layer. Is also good. Also, the alloy layer 3 is formed not only by the solder layer 11 and a part of the first electrode 4 but also by, for example, alloying the entire solder layer 11 and the first electrode 4. Alternatively, it may be formed only by the solder layer 11. Even in these cases, if the content of Sn in the formed alloy layer 3 is 26% by weight or less, it is possible to suppress the aggregation of Sn in the laser light emission region. Therefore, laser oscillation stoppage due to rapid deterioration can be prevented, and a highly reliable semiconductor laser device can be realized.
[0045]
In the first embodiment, the target is a semiconductor laser device. However, the present invention is also effective for a semiconductor optical device in which other general semiconductor optical elements are arranged on the submount 1. For example, for a light emitting diode element (LED) as well, by setting the Sn content in the intervening alloy layer to 26% by weight or less, it is possible to prevent Sn from aggregating in the light emitting region, and to cause light emission due to rapid deterioration. Can be prevented, and a highly reliable semiconductor optical device can be realized.
[0046]
(Embodiment 2)
Next, a semiconductor laser module according to a second embodiment will be described. In the second embodiment, a semiconductor laser module is configured using the semiconductor laser device according to the first embodiment.
[0047]
FIG. 11 is a side sectional view showing the structure of the semiconductor laser module according to the second embodiment of the present invention. The semiconductor laser module according to the second embodiment includes a semiconductor laser element 21 and a submount 28 corresponding to the semiconductor laser device described in the first embodiment. As a housing of the semiconductor laser module, a temperature control module 30 as a temperature control device is disposed on an inner bottom surface of a package 31 formed of ceramic or the like. A base 27 is arranged on the temperature control module 30, a submount 28 is arranged on the base 27, and the semiconductor laser element 21 is fixed on the submount 28 via an alloy layer (not shown). The temperature control module 30 is supplied with a current (not shown) and performs cooling and heating depending on the polarity. That is, when the laser light has a longer wavelength than the desired wavelength, the temperature control module 30 cools and controls the temperature to a lower temperature, and when the laser light has a shorter wavelength than the desired wavelength. Is controlled by heating to a high temperature. This temperature control is specifically controlled based on a detection value of a thermistor 29 disposed on the submount 28 and in the vicinity of the semiconductor laser device 21. The temperature control module 30 is controlled such that the temperature is maintained constant. Further, a control device (not shown) controls the temperature control module 30 so that the temperature of the submount 28 decreases as the drive current of the semiconductor laser element 21 increases. By performing such a temperature control, the output stability of the semiconductor laser device 21 can be improved, which is also effective for improving the yield.
[0048]
On the base 27, a submount 28 on which the semiconductor laser element 21 and the thermistor 29 are arranged, a first lens 32, and a current monitor 26 are arranged. The laser light emitted from the semiconductor laser element 21 is guided to the optical fiber 25 via the first lens 32, the isolator 33, and the second lens 24. The second lens 24 is provided on the package 31 on the optical axis of the laser light, and is optically coupled to an optical fiber 25 connected externally. The current monitor 26 monitors and detects light leaked from the highly reflective film side of the semiconductor laser device 21.
[0049]
Here, in this semiconductor laser module, an isolator 33 is interposed between the semiconductor laser element 21 and the optical fiber 25 so that return light reflected by other optical components does not return into the resonator.
[0050]
In addition, in order to regulate the oscillation wavelength of the semiconductor laser element 21, a fiber grating is disposed inside the optical fiber 25 as necessary, and a structure is formed in which the cavity on the reflection side end face of the semiconductor laser element 21 is formed. In this case, the isolators 33 need to be in-line instead of being arranged in the semiconductor laser module.
[0051]
In the semiconductor laser module according to the second embodiment, the Sn content in the alloy layer formed when the semiconductor laser element 21 is fixed on the submount 28 is set to 26% by weight or less. Therefore, it is possible to realize a highly reliable semiconductor laser module in which Sn does not aggregate on the laser light emission region and laser oscillation does not stop due to rapid deterioration.
[0052]
(Embodiment 3)
Next, an optical fiber amplifier according to a third embodiment will be described. FIG. 12 is a schematic diagram illustrating the structure of the optical fiber amplifier according to the third embodiment. The optical fiber amplifier according to the third embodiment has a semiconductor laser module 35 that functions as an excitation light source and has a structure corresponding to the semiconductor laser module according to the second embodiment. Further, it has an amplifying optical fiber 39 for amplifying the signal light 36 and a WDM coupler 38 for causing the pumping light emitted from the semiconductor laser module 35 to enter the amplifying optical fiber 39. An isolator 37 is arranged before the signal light 36 enters the WDM coupler 38, and an isolator 40 is arranged after the amplification optical fiber 39.
[0053]
The signal light 36 is light emitted from the signal light source and transmitted through the optical fiber, and has a wavelength of 1550 nm. Further, the WDM coupler 38 outputs the pump light emitted from the semiconductor laser module 35 to the amplification optical fiber 39. Further, the isolator 37 has a function of blocking light reflected from the WDM coupler 38 and suppressing noise and the like. The isolator 40 is for blocking the amplification optical fiber 39 from reflected light.
[0054]
In the third embodiment, the amplifying optical fiber 39 uses an erbium-doped optical fiber (EDF). EDF uses erbium ions (Er ³⁺ ) Is added, and has a property of absorbing light having a wavelength of about 980 nm or about 1480 nm to excite electrons in erbium ions. The signal light 36 having a wavelength of 1550 nm is amplified by the excited electrons.
[0055]
Next, the mechanism of optical amplification by the optical fiber amplifier according to the third embodiment will be outlined. The laser light emitted from the semiconductor laser module 35, which is an excitation light source, passes through the WDM coupler 38 and enters the amplification optical fiber 39 from the front. When the wavelength of the incident laser light is 980 nm, the laser light is absorbed by erbium ions doped in the amplification optical fiber 39, and the electrons in the erbium ions are excited.
[0056]
The signal light 36 passes through the isolator 37 and enters the amplification optical fiber 39. As described above, the electrons of the erbium ions doped in the amplification optical fiber 39 are excited, and the signal light 36 is amplified by the energy of the excited electrons.
[0057]
Here, in the semiconductor laser device provided inside the semiconductor laser module 35, the content of Sn in the alloy layer existing between the submount provided therein and the semiconductor laser element is 26% by weight or less. Therefore, it is possible to prevent Sn from aggregating on the laser light emission region during laser oscillation, and to prevent the laser oscillation from being stopped due to rapid deterioration.
[0058]
In the third embodiment, a so-called forward pumping method in which pumping light is pumped from the front of the amplification optical fiber 39 is employed, but the pumping method is not limited to these. For example, the present invention can be applied to an optical fiber amplifier of a so-called backward pumping system, in which signal light and pumping light before amplification are multiplexed in advance and then input to the amplification optical fiber 39. It is. Even in the case of the backward pumping method, since a part of the signal light enters the semiconductor laser module constituting the pump light source, it is necessary to suppress the reflection and the re-emission of a part of the signal light from the pump light source. Because there is. Further, a bidirectional pumping method using both the forward pumping method and the backward pumping method may be used.
[0059]
In the third embodiment, the signal light is amplified by using the EDFA. However, the present invention can be applied to an optical fiber amplifier using an excitation method other than the EDFA. For example, it can be applied to a Raman amplifier. When applied to a Raman amplifier, it is necessary to determine the emission wavelength of the semiconductor laser device included in the pump light source in consideration of the wavelength shift.
[0060]
【The invention's effect】
As described above, according to the first to sixth aspects of the present invention, the alloy layer located between the semiconductor optical element and the submount is configured to have a Sn content of 26% by weight or less, so that light emission is achieved. Aggregation of Sn on the region can be suppressed, and it is possible to prevent the optical output of the semiconductor optical element from stopping.
[0061]
According to the inventions of claims 7 to 13, the solder layer used for fixing the semiconductor optical element on the submount is formed of a solder material not containing Sn. This has the effect of preventing Sn from aggregating and preventing the optical output of the semiconductor optical element from stopping.
[0062]
According to the fourteenth or fifteenth aspect of the present invention, since the semiconductor laser device according to the thirteenth aspect is used, it is possible to prevent Sn from aggregating in the laser light emitting region and stop laser oscillation. This has the effect of realizing a semiconductor laser module in which is prevented.
[0063]
According to the invention of claim 16 or claim 17, since the pumping light source is formed by using the semiconductor laser device of claim 13 or the semiconductor laser module of claim 14 or claim 15, This has the effect of realizing an optical fiber amplifier in which laser oscillation stoppage due to Sn aggregation is prevented.
[Brief description of the drawings]
FIG. 1 is a side view illustrating a structure of a semiconductor laser device according to a first embodiment;
FIG. 2A is a diagram showing a structure in which a semiconductor laser device and a submount constituting a semiconductor laser device are separated from each other, and FIG. 2B shows a state where the semiconductor laser device is fixed on the submount. FIG.
FIG. 3 is a photograph showing an SEM image in the vicinity of a laser light emission region of a semiconductor laser device in which laser oscillation has been stopped due to rapid deterioration.
FIG. 4 is a diagram showing positions of first to fourth regions on which Auger analysis has been performed.
FIG. 5 is a graph showing the result of Auger analysis of a first area.
FIG. 6 is a graph showing a result of Auger analysis of a second area.
FIG. 7 is a graph showing a result of Auger analysis of a third region.
FIG. 8 is a graph showing a result of Auger analysis of a fourth area.
FIG. 9 is a graph showing a distribution of Au in a stacking direction including a laser beam emission region in a semiconductor laser device in which laser oscillation is stopped due to rapid deterioration.
FIG. 10 is a graph showing a distribution of Sn in a stacking direction including a laser beam emission region in a semiconductor laser device in which laser oscillation is stopped due to rapid deterioration.
FIG. 11 is a side sectional view showing the structure of the semiconductor laser module according to the second embodiment;
FIG. 12 is a schematic diagram illustrating a structure of an optical fiber amplifier according to a third embodiment;
FIG. 13 is a schematic graph showing a pattern in which laser oscillation stops in an acceleration test in a semiconductor laser device according to a conventional technique.
[Explanation of symbols]
1 submount
2 Semiconductor laser device
3 Alloy layer
4 First electrode
5 Second electrode
6 Active layer
8 First metal layer
9 Second metal layer
10 Third metal layer
11 Solder layer
12 First area
13 Second area
14 Third area
15 Fourth area
21 Semiconductor laser device
24 lenses
25 Optical fiber
26 Current monitor
27 base
28 Submount
29 Thermistor
30 Temperature control module
31 Package
32 lenses
33 Isolator
35 Semiconductor laser module
36 signal light
37 Isolator
38 coupler
39 Amplifying optical fiber
40 Isolator

Claims (17)

A semiconductor optical device including a base and a semiconductor optical element fixed on the base,
A semiconductor optical device, comprising: an alloy layer disposed between the base and the semiconductor optical element, the alloy layer having a Sn content of 26% by weight or less. The alloy layer is formed by a solder layer disposed on the base and at least a part of a metal electrode disposed on a lower surface of the semiconductor optical element and in contact with the solder layer. 2. The semiconductor optical device according to 1. The metal electrode has a multilayer structure in which a plurality of metal materials are sequentially arranged,
The semiconductor optical device according to claim 2, wherein the alloy layer includes the solder layer and a layer that contacts the solder layer in the multilayer structure. 4. The semiconductor optical device according to claim 3, wherein a layer in contact with the solder layer in the multilayer structure contains Au. The semiconductor optical device according to claim 2, wherein the solder layer contains Au and Sn. The semiconductor optical device according to any one of claims 2 to 4, wherein the solder layer contains Sn and two kinds of metals selected from Pb, Cd, and Ag. The semiconductor optical device according to claim 2, wherein the solder layer is formed of Ge or Si, Au, and unavoidable impurities. The semiconductor optical device according to claim 2, wherein the solder layer is formed of Ag or In, Pb, and unavoidable impurities. The semiconductor optical device according to claim 2, wherein the solder layer is formed of Ag or Zn, Cd, and unavoidable impurities. The semiconductor optical device according to claim 2, wherein the solder layer is formed of Al or Ag, Zn, and unavoidable impurities. The semiconductor optical device according to claim 2, wherein the solder layer is formed of Cu or Te, Zn, Al, and unavoidable impurities. The semiconductor optical device according to claim 2, wherein the solder layer is formed of In, Ag, and unavoidable impurities. 13. The semiconductor optical device according to claim 1, wherein the semiconductor optical element is a semiconductor laser element. A semiconductor optical device according to claim 13,
A transmission path for guiding the laser light emitted from the semiconductor optical device to the outside,
An optical coupling lens system for optically coupling the semiconductor optical device and the transmission path,
A semiconductor laser module comprising: A light detector for measuring the light output of the semiconductor optical device,
A temperature control module for controlling the temperature of the semiconductor optical device;
An isolator,
The semiconductor laser module according to claim 14, further comprising: An excitation light source comprising the semiconductor optical device according to claim 13 or the semiconductor laser module according to claim 14 or 15;
An amplification optical fiber;
A coupler for optically coupling the excitation light source and the amplification optical fiber,
An optical fiber amplifier comprising: 17. The optical fiber amplifier according to claim 16, wherein the amplification optical fiber is doped with erbium.

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