JP2003347649A - Light emitting device and its producing process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable light emitting device comprising a semiconductor laser device and an optical component, and to provide a process for producing the highly reliable light emitting device. <P>SOLUTION: A highly reliable light emitting device can be obtained by providing a buffer part (a protrusion 9 on Fig. 1) for preventing contact of the exit end face of the semiconductor laser device 1 and the entrance end face of the optical component between the semiconductor laser device 1 and the optical component (a wavelength conversion element 2 on Fig. 1). The process for producing the highly reliable light emitting device comprises a step for providing a buffer part for preventing contact of the exit end face and the entrance end face on at least one member selected from the semiconductor laser element, the optical component and a base. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device having a semiconductor laser element and an optical component, and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, as a light source of a laser used for a high-density optical disk or the like, a direct-coupling type laser in which a semiconductor laser and a wavelength conversion element are combined has been attracting attention (for example, SHG (Second Harmonic as a wavelength conversion element). Generat
ion) blue laser, Kitaoka et al., "M
iniaturized Blue Laser using Second Harmonic Gener
ation ", Jpn. J. Appl. Phys. vol.39 (2000) pp.3416-
3418, etc.). With a direct-coupled laser, a light-emitting device that is significantly smaller and lighter than when a lens-coupled laser or the like is used can be realized.

FIG. 10 shows a configuration example of a light emitting device using a conventional direct coupling type laser. In the example shown in FIG. 10, the wavelength conversion element 102 and the semiconductor laser element 101 are bonded on the submount 103. Semiconductor laser device 101
The light emitted from the waveguide 104 (generally, a portion corresponding to a stripe region in the active layer of the semiconductor laser device) is guided to the waveguide 105 of the wavelength conversion device 102 and is converted into laser light of a different wavelength. . At this time, the waveguide 104 of the semiconductor laser element 101 and the wavelength conversion element 10
The amount of light propagation is determined by the degree of optical coupling with the second waveguide 105. Such an optical coupling degree is called a coupling efficiency. In particular, because the conversion efficiency of the wavelength conversion element is proportional to the square of the incident light amount, the light emitting device using the direct coupling type laser has the above coupling efficiency. Further improvements are required.

[0004]

Generally, the coupling efficiency is
It is mainly determined by the relative position of the optical axis of each waveguide of the wavelength conversion element and the semiconductor laser element. In order to obtain good coupling efficiency, it is required that both optical axes coincide with an accuracy of ± 0.2 μm. For such high-precision adjustment, a method is used in which the semiconductor laser element is actually caused to emit light, and the relative positions of the two are adjusted and fixed so that the amount of light coming out of the output end face of the wavelength conversion element is maximized. (This method is called active alignment).

The shorter the distance between the input end face of the wavelength conversion element and the output end face of the semiconductor laser element, the greater the coupling efficiency. However, when the distance is 0.5 μm or less, the coupling efficiency becomes almost constant. For this reason, it is desired to perform active alignment while maintaining the distance at 0.5 μm or less. However, at such a small distance, the incident end face of the wavelength conversion element and the emission end face of the semiconductor laser element come into contact with each other due to vibration or the like generated when the wavelength conversion element and the semiconductor laser element are assembled, so that the emission of the semiconductor laser element may occur. There was a problem that stress was applied to the end face. When stress is applied to the emission end face, crystal defects may be generated inside the semiconductor laser device, and the output and life may be reduced.

On the other hand, a method has been proposed in which the incident end face of the wavelength conversion element is formed in a tapered shape so that the emission end face of the semiconductor laser element and the incident end face of the wavelength conversion element do not directly contact each other (Japanese Patent Laid-Open No. 6-1994). 338650). However, in this method, a part of the light emitted from the semiconductor laser device is reflected by the incident end face of the wavelength conversion device, and the light amount may be insufficient.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a highly reliable light emitting device in which the emission end face of a semiconductor laser element does not directly contact the incidence end face of an optical component, and a method of manufacturing the same.

[0008]

In order to achieve the above object, a light emitting device according to the present invention is arranged such that a semiconductor laser element for emitting a laser beam from an emission end face and the laser beam is received at an incidence end face. A light emitting device comprising: an optical component; and a buffer unit that prevents contact between the emission end face and the incidence end face between the semiconductor laser element and the optical component. . In such a light emitting device, the emitting end face of the semiconductor laser and the incident end face of the optical component do not directly contact each other, so that a highly reliable light emitting device with few problems such as crystal defects can be obtained. .

In the above light emitting device, it is preferable that the buffer is provided with at least one member selected from a semiconductor laser element and an optical component. Further, a substrate portion of a semiconductor laser device can be used as the buffer. In this case, the formation of the emission end face and the formation of the buffer portion of the semiconductor laser element can be performed simultaneously.

In the above light emitting device, an oxide can be used as the buffer. In this case, formation of the end face protective film on the emission end face of the semiconductor laser element and formation of the buffer portion can be performed simultaneously.

In the above light emitting device, a resin can be used as the buffer. Further, the glass transition temperature of the resin is preferably -10 ° C or lower. In this case, a buffer portion having sufficient elasticity can be provided in a general operating temperature range of the light emitting device.

According to a method of manufacturing a light emitting device of the present invention, a semiconductor laser element for emitting a laser beam from an emission end face, an optical component for receiving the laser beam at an incidence end face, and the semiconductor laser element and the optical component are installed. A light emitting device comprising: a base; and a contact between the emission end face and the incidence end face on at least one member selected from the semiconductor laser element, the optical component, and the base. A step of providing a buffer, and the semiconductor laser element and the light emitting device are arranged such that the laser beam is incident on the incident end face and the buffer is located between the semiconductor laser element and the optical component. And arranging it on a base. According to such a manufacturing method, the emitting end face of the semiconductor laser and the incident end face of the optical component do not directly contact with each other, so that a highly reliable light emitting device with less problems such as crystal defects can be obtained. .

[0013]

Preferred embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a schematic diagram showing a configuration example of a light emitting device according to the present invention. In addition, in order to make a structure easy to understand, it is the figure which used the cross section partially. In the example shown in FIG. 1, a semiconductor laser device 1 and a wavelength conversion device 2 are formed on a submount 3. The submount 3 is arranged on a heat sink 4 for heat radiation. The entire light emitting device is covered by a cover 5 to protect the light emitting device from external impacts and the like. A window glass 6 is attached to an opening provided in a part of the cover, and a laser beam emitted from the wavelength conversion element 2 is emitted to the outside through the window glass 6.

As the semiconductor laser element 1, any kind of semiconductor laser element can be used. For example, when the semiconductor laser element 1 is used as a light emitting device for an optical disk, a semiconductor laser element using an AlGaAs-based semiconductor having few crystal defects and high reliability is used. Is preferred. AlGaAs semiconductor laser devices are in the infrared region (wavelength
820 nm).

The wavelength conversion element 2 is limited to SHG.
It is possible to use all sorts of things,
For example, when using SHG, since the conversion efficiency is high, L
iNbO _ThreeIs preferable. LiNbO_ThreeSystem wavelength
Combined conversion device and AlGaAs semiconductor laser device
If you can get a blue (wavelength 410nm) laser beam
it can.

As the submount 3, a material having excellent thermal conductivity and a thermal expansion coefficient substantially equal to that of the semiconductor laser element, for example, silicon, aluminum nitride, or the like can be used. As the cover 5, the shape processing is easy, and the light emitting device can be reduced in weight.
It is preferable to use a resin. Note that copper is preferably used as the heat sink 4 because it has good thermal conductivity.

Semiconductor laser device 1 and wavelength conversion device 2
Have waveguides 7 and 8, respectively. In order to obtain a light emitting device having good characteristics, waveguides 7 and 8
Is preferably adjusted so that the respective optical axes coincide with an accuracy of ± 0.2 μm or less.

In the example shown in FIG. 1, a projection 9 serving as a buffer is provided on the emission end face of the semiconductor laser device 1.
The convex portion 9 can prevent direct contact between the emission end face of the semiconductor laser element 1 and the incidence end face of the wavelength conversion element 2 (that is, the waveguide 7 and the waveguide 8). Therefore, the stress applied to the semiconductor laser element 1 and the wavelength conversion element 2 can be suppressed even during active alignment or the like, and a highly reliable light emitting device can be obtained.

FIG. 2 is a schematic diagram showing the structure of the semiconductor laser device 1 in the example shown in FIG. The semiconductor laser device 1 will be described using an AlGaAs semiconductor laser device as an example. Further, the semiconductor laser device 1 in FIG. 2 is illustrated upside down with respect to the semiconductor laser device in FIG. 1 for convenience of description.

The semiconductor laser device 1 includes an n-type GaAs substrate 11
An n-type AlGaAs cladding layer 12 is disposed thereon, and
Undoped AlGaAs / GaAs quantum well active layer 13, p-type AlGaAs
The first cladding layers 14 are sequentially stacked. Lamination of each layer may be performed using a general technique such as a metal organic chemical vapor deposition method.

On the p-type AlGaAs first cladding layer 14, an AlGaAs current blocking layer 15 is laminated on a region of the undoped AlGaAs / GaAs quantum well active layer 13 other than immediately above the stripe portion 21. The AlGaAs current blocking layer 15 is formed by first stacking the entire surface of the p-type AlGaAs first cladding layer 14 by using a metal organic chemical vapor deposition method or the like, and then forming a stripe by using a general method such as a photolithography method. Part 21
May be deleted.

A p-type AlGaAs second cladding layer 16 is provided on the AlGaAs current block layer 15 and the stripe portion 21, and a contact layer 17 is formed on the p-type AlGaAs second cladding layer 16. When a current flows between the n-type GaAs substrate 11 and the contact layer 17, the current is confined in the stripe portion 21 by the AlGaAs current block layer 15, and the semiconductor laser device 1 can emit light efficiently. Further, the Al mixed crystal ratio of the AlGaAs current block layer 15 is
If the Al composition ratio is higher than the p-type AlGaAs first cladding layer 14 and the p-type AlGaAs second cladding layer 16, light can be confined in the stripe portion 21 by the AlGaAs current blocking layer 15. At this time, the stripe portion 21 of the active layer 13 becomes the waveguide 7 of the semiconductor laser device 1 shown in FIG.

The semiconductor laser device 1 shown in FIG.
A projection 9 serving as a buffer is provided in contact with the emission end face 18. The projection 9 may be newly added to the emission end face 18 or may be formed by extending the n-type GaAs substrate 11 in the laser emission direction.

When a substrate is used as the projection 9, the formation of the emission end face of the semiconductor laser device and the formation of the buffer can be performed simultaneously. For example, when the emission end face of the semiconductor laser element is formed by an etching method, the projection 9 can be formed by stopping the etching in the middle of the substrate.

The direction of the optical axis of the laser beam (ie, the waveguide 7
The thickness of the projection 9 in the direction of the optical axis) is 0.1 μm or more and 0.5
μm or less is preferred. Within this range, contact between the emission end face of the semiconductor laser element and the incidence end face of the optical component (in this embodiment, the wavelength conversion element) can be sufficiently prevented, and the coupling efficiency between the semiconductor laser element and the optical component can be reduced. Can be obtained sufficiently.

The shape of the convex portion 9 may be any shape as long as a laser beam can be emitted from the semiconductor laser device 1 (unless the convex portion 9 blocks the laser beam by hiding the laser beam emission point of the device). It does not matter.

Further, an oxide can be used for the projection 9. In general, it is preferable to form an end face protective film using an oxide on the emission end face 18 and the other end face 19 of the semiconductor laser element. The formation of the buffer portion can be performed simultaneously.

As the oxide, for example, silicon oxide, titanium oxide, aluminum oxide and the like are preferable. Convex part 9
When aluminum oxide is used as the material of the aluminum oxide, since the thermal conductivity of aluminum oxide is higher than other oxide materials,
It can also serve to diffuse heat near the emission end face of the laser element.

In addition, a resin can be used for the projection 9. Generally, resin is softer than oxide or substrate,
The shock at the time of contact can be effectively buffered.

The resin preferably has a glass transition temperature of -10 ° C. or lower. Typical operating temperatures for light emitting devices are higher than -10C. Therefore, when the glass transition temperature of the resin is −10 ° C. or less, the convex portion 9 has sufficient elasticity as a buffer portion in the operating temperature range, and the stress applied to the semiconductor laser element can be further suppressed.

By providing the projection 9 as described above,
During active alignment or use, the stress applied to the semiconductor laser device is suppressed, and the output of the laser device can be prevented from lowering due to crystal defects or the like caused by the stress. Therefore, according to this embodiment, a highly reliable light emitting device can be provided.

The semiconductor laser device used in the light emitting device of the present invention is not limited to the GaAlAs-based semiconductor laser device described in the present embodiment.

(Embodiment 2) FIG. 3 is a schematic view showing another configuration example of the light emitting device according to the present invention. As in FIG. 1, the drawing is partially a cross-sectional view. The basic configuration using the semiconductor laser element 31 and the wavelength conversion element 32 is the same as the example shown in FIG. 1, but in the example shown in FIG. 3, the wavelength conversion element 32 includes a buffer section 33. Further, the wavelength conversion element 32 and the semiconductor laser element 31
It has waveguides 34 and 35, respectively.

FIG. 4 shows the structure of the wavelength conversion element 32 in the example shown in FIG. FIG. 4 shows the wavelength conversion element 3 shown in FIG.
FIG. 2 is a schematic diagram of the light-emitting element 2 as viewed from the incident end face side. A buffer 33 is formed on the incident end face of the wavelength conversion element 32. An opening 36 is provided in the buffer 33 so that a laser beam can be incident on the waveguide 34.

The shape of the buffer portion 33 is not limited to the example shown in FIG. 4, but may be any shape as long as the laser beam can enter the waveguide 34.

The direction of the optical axis of the laser beam (ie, the waveguide 3
As in the first embodiment, the thickness of the buffer portion 33 in the direction of the optical axis 4 is preferably 0.1 μm or more and 0.5 μm or less.

By providing the buffer 33 as described above, the stress applied to the semiconductor laser device during active alignment or use is suppressed, and the output of the laser device is prevented from lowering due to crystal defects caused by the stress. it can. Therefore, according to this embodiment, a highly reliable light emitting device can be provided.

The buffer may be provided in both the semiconductor laser device and the wavelength conversion device. In addition, an independent buffer is provided between the semiconductor laser element and the wavelength conversion element.
For example, it can be arranged on a submount serving as a base.

In the first and second embodiments, examples in which a wavelength conversion element is used as an optical component have been described. However, the effects of the present invention can be obtained even when another optical component such as a lens or an optical fiber is used. it can.

Embodiment 3 In this embodiment, an example of a method for manufacturing the light emitting device shown in FIG. 1 will be described.

First, an example of a method for manufacturing a semiconductor laser device having a projection serving as a buffer will be described with reference to FIG.
In this example, the protrusion is made of the same material as an end face protective film described later.

First, a semiconductor laser device 1 manufactured by using a general method such as a metal organic chemical vapor deposition method is mounted on a jig 51.
Arrange them on the top (FIG. 5A). At this time, the semiconductor laser elements 1 may be arranged such that the end face opposite to the emission end face 18 is in contact with the jig 51. As shown in FIG. 5A, the waveguide 7 of the semiconductor laser device 1 faces in the up-down direction. As the jig 51, stainless steel, aluminum, or the like can be used.

Subsequently, spacers 52 are arranged without gaps between the semiconductor laser elements 1 (FIG. 5B). At this time, it is sufficient that the thickness 54 of the spacer in the direction of the waveguide 7 of the laser element is larger than the distance 53 (resonator length) between the end faces of the semiconductor laser element 1. As the spacer 52, a material having excellent thermal conductivity, such as AlN or silicon, can be used.

Next, an end face protective film is formed on the emission end face 18 of the semiconductor laser device 1 using a low vacuum sputtering apparatus. At this time, the particles of the material constituting the end face protective film may fly from a direction perpendicular to the emission end face 18.

Aluminum oxide, silicon oxide, titanium oxide and the like can be used as the material of the end face protective film. Above all, when aluminum oxide is used, heat at the emission end face of the laser element can be diffused because aluminum oxide has high thermal conductivity.

Thereafter, using a low vacuum sputtering apparatus,
As shown in (c), the emission end face 1 of the semiconductor laser device 1
Particles of the material constituting the convex portion are made to fly from a direction oblique to 8. The angle θ at which the particles fly with respect to the emission end face 18 may be an angle at which the particles do not reach the laser beam emission point 55 (the emission end face of the waveguide 7) due to the spacer 52 serving as an obstacle. At this time, no convex portion is formed in a portion on the emission end face 18 which is shaded by the spacer 52. Further, by setting the atmosphere of the sputtering to a low vacuum (10 ⁻⁵ Pa or less), particles of the material forming the projections can fly at a certain angle. Thus, the laser element 1 having the projection 9 on the emission end face 18
Can be obtained (FIG. 5D).

It is preferable that the same material as that of the end face protective film is used for the projection 9. Convex portions can be formed simultaneously with the formation of the end face protective film.

The thickness of the projection 9 in the direction of the optical axis of the laser beam (that is, in the direction of the optical axis of the waveguide 7) is preferably 0.1 μm or more and 0.5 μm or less.

The stacking of the projections is not limited to the low vacuum sputtering method, but a general stacking method such as a low vacuum resistance heating method and a low vacuum laser deposition method can be used. Also, to change the angle θ at which particles fly,
The method of inclining the jig 51 is simple.

By using the above method, a semiconductor laser device having a projection serving as a buffer on the emission end face can be manufactured.
It can be obtained efficiently and simply.

Next, an example of a method for manufacturing a light emitting device will be described with reference to FIG.

First, the semiconductor laser device 1 having the projection 9 serving as a buffer shown in FIG. 5 is arranged on the submount 3 serving as a base (FIG. 6A). At the time of disposition, it is preferable to perform fusion using a gold-tin alloy or the like.

Subsequently, the wavelength conversion element 2 having the waveguide 8
Is prepared (FIG. 6 (b)), and the wavelength conversion element 2 and the semiconductor laser element 1 are brought close to each other on the submount 3 in a state where the laser beam 61 is emitted from the semiconductor laser element 1 (FIG. 6 (c)). ).

Next, the semiconductor laser element 1 and the wavelength conversion element 2 are brought close to each other until the coupling efficiency becomes as large as possible, and active alignment is performed so that the intensity of the light 62 emitted from the wavelength conversion element 2 becomes maximum ( FIG. 6D).

At this time, in order to increase the intensity of the emitted light of the wavelength conversion element as much as possible, the distance between the emission end face of the semiconductor laser element and the incidence end face of the wavelength conversion element is preferably 1.0 μm or less, particularly It is preferably 0.5 μm or less. It is preferable that the optical axis of the waveguide 7 of the semiconductor laser device 1 and the optical axis of the waveguide 8 of the wavelength conversion element 2 coincide with an accuracy of ± 0.2 μm.

Even when the semiconductor laser device 1 and the wavelength conversion device 2 are extremely close to each other due to vibration or the like during the active alignment, the semiconductor laser device 1 is provided with the convex portion 9 serving as a buffer. Direct contact between the emission end face of the laser element 1 and the incidence end face of the wavelength conversion element 2 can be prevented (FIG. 6E). Therefore, it is possible to provide a manufacturing method in which problems such as crystal defects do not occur in the semiconductor laser device.

Thereafter, light emission of the semiconductor laser element 1 is stopped, and the wavelength conversion element 2 is fixed to the submount 3 (FIG. 6).
(F)). For fixing, an ultraviolet curable resin or the like can be used. When an ultraviolet-curable resin is used, the ultraviolet-curable resin may be applied to the submount 3 or the wavelength conversion element 2 in advance in the state shown in FIG.

Finally, the submount on which the semiconductor laser element and the wavelength conversion element are arranged as described above is fixed in a package having a cover, a window glass and a heat sink using a conductive adhesive. Can be obtained.

By employing the method for manufacturing a light emitting device as described above, it is possible to prevent a problem such as a crystal defect from occurring in the semiconductor laser element during the manufacture of the light emitting device, and to obtain a light emitting device with higher reliability. be able to.

In this embodiment, an example is shown in which a wavelength conversion element is used as an optical component. However, the effects of the present invention can be obtained even when another optical component such as a lens or an optical fiber is used.

Embodiment 4 In this embodiment, an example of a method for manufacturing the light emitting device shown in FIG. 3 will be described.

First, an example of a method for manufacturing a wavelength conversion element having a buffer will be described with reference to FIG. In this example, the wavelength conversion element has a buffer section made of resin.

FIG. 7A shows the wavelength conversion element 32 before the buffer section is arranged. The wavelength conversion element 32 includes a waveguide 34
have. First, the incident end face 71 of the wavelength conversion element 32
Next, a coating 72 made of an ultraviolet-sensitive resin is formed.
(B)). The direction of the optical axis of the laser beam (that is, the waveguide 34
The thickness of the coating 72 in the direction of the optical axis may be adjusted according to the thickness required as a buffer. In addition, as the ultraviolet photosensitive resin, a positive photoresist that is frequently used in a semiconductor manufacturing process or the like can be used.

As a method for forming the coating 72 on the incident end face 71, first, a liquid ultraviolet-sensitive resin before curing is put into a beaker, and then the end face of the wavelength conversion element is brought into contact with the liquid level of the resin. (For example, when the above photoresist is used as an ultraviolet-sensitive resin, heat to 50 ° C.)
Thus, the ultraviolet-sensitive resin may be temporarily cured. The thickness of the coating 72 in the optical axis direction of the laser beam can be adjusted by controlling the temperature (viscosity) of the ultraviolet photosensitive resin at the time of the contact.

Next, from the end face opposite to the incident end face 71,
Ultraviolet light is incident on the waveguide 34. When the ultraviolet rays are incident, it is efficient if the ultraviolet light emitting device and the waveguide 34 are adjusted so as to be coupled to each other by, for example, 95% or more. The incident ultraviolet light reaches the incident end face 71 through the waveguide 34 and exposes the coating 72. After that, if the ultraviolet-sensitive resin is developed using an alkaline solution such as a KOH aqueous solution, the coating 7 is obtained.
2, the portion exposed by the ultraviolet light passing through the waveguide 34 is removed, and the waveguide 3 as shown in FIG.
The wavelength conversion element provided with the buffer 33 having the opening 36 in the portion 4 can be manufactured.

Thereafter, active alignment and the like are performed together with the semiconductor laser element in the same manner as in Embodiment 3, whereby the light emitting device shown in FIG. 3 can be obtained.

By employing the method for manufacturing a light emitting device as described above, it is possible to prevent a problem such as a crystal defect from occurring in the semiconductor laser element during the manufacture of the light emitting device, and to obtain a light emitting device with higher reliability. be able to.

In addition to the above-described method of forming an opening utilizing the photosensitizing function of the photo-sensitive resin, a high-intensity laser beam is propagated through the waveguide of the wavelength conversion element to form the resin portion. Can be evaporated to form an opening.

In the third and fourth embodiments, an example of a method of manufacturing a light emitting device in which a buffer portion is provided on a semiconductor laser element or an optical component has been described. However, the buffer portion may be provided on a base or may be provided independently. A buffer may be used. In that case, the semiconductor laser element and the light emitting device may be arranged on the base such that the buffer section is located between the semiconductor laser element and the optical component.

[0071]

The present invention will be described in more detail with reference to the following examples.

A light emitting device as shown in FIG. 1 was manufactured by using an AlGaAs semiconductor laser element as a semiconductor laser element and a LiNbO ₃ type wavelength conversion element as an optical component.

First, n-type metalorganic vapor phase epitaxy is used.
By forming the layers shown in FIG. 2 on a GaAs substrate, GaAl
An As-based semiconductor laser device was fabricated. The cavity length of the manufactured laser device was 500 μm.

Subsequently, by using the same method as in the third embodiment, a projection serving as a buffer was formed on the emission end face of the semiconductor laser device. The same material (aluminum oxide) as the end face protective film was used for the projection.

First, the semiconductor laser elements and the spacers were alternately arranged on a stainless steel jig without any gap. The thickness of the spacer (spacer thickness 54 shown in FIG. 5)
515 μm AlN was used. Next, using a low-vacuum sputtering apparatus, as an end face protective film of the emission end face of the semiconductor laser element,
An aluminum oxide film having a thickness of 0.12 μm was laminated. The reflectance of the end face protective film was 4%, and the laser beam could be efficiently extracted.

Subsequently, the jig was tilted at 45 ° to form a projection having a thickness (thickness in the optical axis direction of the laser beam) of 0.3 μm. By tilting the jig by 45 °, the spacer becomes an obstacle,
No projection was formed at the laser beam emission point of the semiconductor laser device.

In this embodiment, using the above-described method, a sample of a semiconductor laser device 10 having a convex portion serving as a buffer portion, and a semiconductor laser device 10 having only an end face protective film formed without forming a convex portion. A sample was prepared.

Next, using the semiconductor laser device having the projection on the emission end face and the semiconductor laser element without the projection on the emission end face prepared as described above, the third embodiment was used.
A light emitting device was manufactured according to the method described in (1).

The active alignment performed when manufacturing the light emitting device was performed in a state where the distance between the emission end face of the semiconductor laser element and the incidence end face of the wavelength conversion element was 0.4 μm. During the active alignment, vibration applied from outside to the collet (which holds the wavelength conversion element by suction) was checked with a vibrometer, and it was found that low frequency vibration of about 10 Hz and amplitude of about 1.3 μm was superimposed. .

A reliability test was performed on the light emitting device manufactured as described above. 8 and 9 show the results of a reliability test of a light emitting device using a semiconductor laser element having a convex portion on the output end face and a light emitting device using a semiconductor laser element having no convex portion on the output end face.

The reliability test was performed by operating each light emitting device at a constant current in an atmosphere of 60 ° C. and measuring a change in light output with respect to the test time. The initial output is 25
mW, and the average operating current of all samples was 194 mA.

As shown in FIG. 8, when a projection serving as a buffer is provided on the emission end face of the laser element, contact between the emission end face of the laser element and the incidence end face of the wavelength conversion element is suppressed during active alignment. Yes, for all samples with n = 10,
A stable light output was obtained for 1600 hours or more. On the other hand, as shown in FIG. 9, when there was no protrusion serving as a buffer on the emission end face of the laser element, a sharp decrease in light output was observed in a plurality of samples as the test time increased.

When the output end face of the laser element of the sample whose output was lowered was observed using a transmission electron microscope (TEM), it was found that a crystal defect occurred in the output end face. On the other hand, in the sample in which a stable light output could be obtained for 1600 hours or more, no crystal defect was observed on the emission end face of the laser element. In a sample whose output has decreased, the incident end face of the wavelength conversion element may directly contact the emission end face of the semiconductor laser element due to the vibration applied during the active alignment, and the emission end face of the laser element may be damaged.
If the emission end face is damaged, even if it is a fine crystal defect that does not reduce the light output in the initial state, the crystal defect will expand over time and eventually cause a sharp decrease in the light output. Conceivable.

[0084]

As described above, according to the present invention,
It is possible to obtain a highly reliable light emitting device in which the emission end of the semiconductor laser element does not directly contact the incidence end of the optical component. Further, according to the present invention, a highly reliable method for manufacturing a light-emitting device can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic view illustrating an example of a light emitting device according to the present invention.

FIG. 2 is a schematic view showing a structural example of a semiconductor laser device according to the present invention.

FIG. 3 is a schematic view illustrating an example of a light emitting device according to the present invention.

FIG. 4 is a schematic view showing a structural example of an optical component according to the present invention.

FIG. 5 is a schematic view for explaining steps of a method for manufacturing a light emitting device according to the present invention.

FIG. 6 is a schematic view for explaining steps of an example of a method for manufacturing a light emitting device according to the present invention.

FIG. 7 is a schematic view for explaining steps of an example of a method for manufacturing a light emitting device according to the present invention.

FIG. 8 is a diagram showing a result of a reliability test of the light-emitting device according to the present invention, which is measured by an example.

FIG. 9 is a diagram showing a result of a reliability test of a conventional light emitting device measured according to an example.

FIG. 10 is a schematic view illustrating an example of a conventional light emitting device.

[Explanation of symbols]

1,31,101 Semiconductor laser device 2, 32, 102 wavelength conversion element 3, 103 submount 4 heat sink 5 Cover 6 Window glass 7, 8, 34, 35, 104, 105 waveguide 9 convex part 11 n-type GaAs substrate 12 n-type AlGaAs cladding layer 13 Undoped AlGaAs / GaAs quantum well active layer 14 p-type AlGaAs first cladding layer 15 AlGaAs current block layer 16 p-type AlGaAs second cladding layer 17 Contact layer 18 Exit face 19 End face 21 Stripe part 33 buffer 36 opening 51 jig 52 Spacer 53 Distance between end faces 54 Spacer Thickness 55 Laser beam emission point 61 laser beam 62 Outgoing light 71 Incident end face 72 Coating

Claims (14)

[Claims] 1. A light emitting device comprising: a semiconductor laser element for emitting a laser beam from an emission end face; and an optical component arranged to receive the laser beam on an incidence end face. A light-emitting device, comprising a buffer between the optical component and the light-emitting end surface for preventing contact with the incident end surface. 2. The light emitting device according to claim 1, wherein at least one member selected from the semiconductor laser element and the optical component includes the buffer. 3. The light emitting device according to claim 1, wherein the thickness of the buffer in the optical axis direction of the laser beam is 0.1 μm or more and 0.5 μm or less. 4. The buffer according to claim 1, wherein the buffer is made of an oxide.
The light emitting device according to any one of claims 1 to 3. 5. The buffer according to claim 1, wherein the buffer is made of a resin.
5. The light emitting device according to any one of 4. 6. The light emitting device according to claim 5, wherein a glass transition temperature of the resin is −10 ° C. or less. 7. The light emitting device according to claim 1, wherein said optical component is a wavelength conversion element. 8. A light emitting device comprising: a semiconductor laser device that emits a laser beam from an emission end surface; an optical component that receives the laser beam at an incidence end surface; and a base on which the semiconductor laser device and the optical component are installed. A method of manufacturing a device, comprising: providing a buffer on at least one member selected from the semiconductor laser element, the optical component, and the base to prevent contact between the emission end face and the incidence end face; Arranging the semiconductor laser element and the light emitting device on the base such that a laser beam is incident on the incident end face and the buffer portion is located between the semiconductor laser element and the optical component; A method for manufacturing a light emitting device, comprising: 9. The method according to claim 8, wherein the buffer section is provided on the semiconductor laser element. 10. The step of providing the buffer section, the step of laminating a material forming the buffer section on the emission end face of the semiconductor laser element, and the step of: providing the material at a laser beam emission point of the semiconductor laser element. The method for manufacturing a light emitting device according to claim 9, further comprising a step of arranging obstacles in advance in order to prevent stacking. 11. The method for manufacturing a light emitting device according to claim 10, wherein the material is laminated obliquely with respect to the emission end face. 12. The method according to claim 8, wherein the buffer is provided on the optical component. 13. The method according to claim 8, wherein a distance between the emission end face of the semiconductor laser element and the incidence end face of the optical component is 1.0 μm or less. 14. The method according to claim 8, wherein the thickness of the buffer in the optical axis direction of the laser beam is 0.1 μm or more and 0.5 μm or less.