JPH08220368A - Optical semiconductor devic module - Google Patents

Abstract

PURPOSE: To provide an optical semiconductor device module where reflected light on the surfaces of optical parts is reduced. CONSTITUTION: This optical semiconductor device module is provided with a package 55, an optical semiconductor element for example, semiconductor laser) 12 disposed in the package 55, and an optical fiber 5 which is extended over the inside and the outside of the package and whose one end is optically coupled with the semiconductor laser 12. The package 55 is formed of resin 54 which is transparent with respect to light transmitted through the optical fiber 5 and whose refractive index is nearly the same as that of a part where the light through the optical fiber 5 passes. Space between the optical coupling surfaces of the laser 12 and the optical fiber 5 is filled with the transparent resin 54, and the optical fiber 5 and the laser 12 are integrated by means of the resin 54. The refractive index of the resin 54 is within ±10% of the refractive index of the part (core) where the light through the optical fiber 5 passes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical semiconductor device module, and more particularly to a technique effectively applied to optical coupling of an optical fiber with an optical semiconductor element such as a semiconductor laser, a light emitting diode or a light receiving element. .

[0002]

2. Description of the Related Art A conventional optical semiconductor device module has an airtight sealing structure so that oxygen and moisture do not directly contact an optical semiconductor element (optical semiconductor chip) in order to ensure long-term stability. The optical semiconductor element and the optical fiber are optically coupled via a lens or the like. Here, if there is reflection from the lens or the optical fiber, it is superimposed on the emitted light or the received light as noise, and the transmission quality deteriorates. Therefore, measures are taken such as coating the lens or the end face of the optical fiber with a non-reflective film, or inclining the light input / output surface with respect to the optical axis.

Optical semiconductor device modules currently in practical use are roughly classified into a coaxial type and a box type such as a butterfly type.

The coaxial type optical semiconductor device module is shown in FIG.
The structure is as shown in. In the figure, 1 is a cap-sealed semiconductor laser device, 2 is a combined body fixed to the semiconductor laser device 1 with its optical axis aligned, and 3 is an optical fiber cord 4 and a protrusion at the tip of the optical fiber cord 4. It is a ferrule that guides the formed optical fiber 5.

The semiconductor laser device 1 has an electric input / output terminal 9
Metal stem with attached (coaxial type CD stem)
10 and a metal cap 11 that is airtightly fixed to the main surface (upper surface) side of the stem 10 forms a package.

A heat sink 13 to which an optical semiconductor element 12 made of a semiconductor laser is fixed is fixed to the side surface of the main surface of the stem 10. Laser light 17 is emitted from the upper surface and the lower surface of the optical semiconductor element 12. Therefore, the ceiling portion of the cap 11 is perforated and
A transparent glass plate 14 made of sapphire glass or the like coated with a non-reflective film so as to block this hole is hermetically fixed via a low melting point glass, and a light extraction window 15 is formed.

A monitor photodiode 16 is fixed to the stem 10 and receives a laser beam 17 emitted from the optical semiconductor element 12.

The combination 2 is the semiconductor laser device 1.
The metal frame 20 is fitted into the cap 11 and is connected to the metal frame 20 at the joint portion 19 by soldering or laser welding, and the metal frame 22 is connected to the metal frame 20 at the joint portion 21 by soldering or laser welding.

A hole is formed in the ceiling portion of the metal frame 20, and a lens 23 coated with an antireflection film is fixed in a penetrating state. This lens 2
3 guides the laser beam 17 emitted from the optical semiconductor element 12.

The metal frame 22 is a cylinder for guiding the ferrule 3 attached to the tip of the optical fiber cord 4.

In such an optical semiconductor device module, the ferrule 3 supporting the optical fiber 5 is assembled in the assembly.
After preparing the metal frame 22 in which is inserted and fixed, the metal frame 20 in which the lens 23 is fixed, and the semiconductor laser device 1, the metal frame 20 is overlapped on the semiconductor laser device 1, and the metal frame 22 is overlapped on the metal frame 20. While monitoring the output laser light 17 (output light), the positions of the lens 23 and the optical fiber 5 are finely adjusted, and the optical coupling to the optical fiber 5 is maximized by soldering or laser welding. Metal frame 2
0 is fixed to the cap 11, and the metal frame 22 is fixed to the metal frame 20.

In the box-type optical semiconductor device module, as shown in FIG. 8, a plurality of electric input / output terminals 9 are projected from the bottom of the box-type package 30 formed of a metal frame, and the box-shaped package 30 is formed from one end of the package 30. Optical fiber cord 4
The structure is such that the guide 31 that guides is projected.
A Peltier element 32 is arranged at the bottom of the package 30. On the Peltier element 32, a support plate 33 to which each component is fixed is fixed.

An optical semiconductor element 12 made of a semiconductor laser is fixed to the upper surface of the support plate 33 via a submount 34. From the left and right sides of the optical semiconductor element 12, laser light 1
7 is emitted. Support plate 33 on the left side of the optical semiconductor element 12
The monitor photodiode 16 that receives the laser light 17 that becomes the rear light is fixed on the upper side of the support 35.

The submount 34 and the support 35 are also provided.
A thermistor 36 for measuring the temperature is fixed on the support plate 33 between and.

On the other hand, at the tip of the optical fiber cord 4 supported by the guide 31 facing the inside of the package 30, the cord portion is stripped off, and the optical fiber 5 consisting of a core and a clad.
Is exposed for the desired length. The optical fiber 5 is supported in the middle by an optical fiber fixing portion 37.

The tip of the optical fiber 5 has a lens 39 mounted on a support 38 fixed on a support plate 33.
Is in contact with

The lens 39 and the optical semiconductor element 12 are also provided.
A lens 40 is also mounted on the support 38 between and.

The optical axes of the optical semiconductor element 12, the lens 40, the lens 39 and the optical fiber 5 coincide with each other. As a result, the laser light 17 that is the front light of the optical semiconductor element 12 is
It passes through the lenses 40 and 39 and is taken into the core of the optical fiber 5.

The tip end surface of the optical fiber 5 and the surfaces of the lenses 39 and 40 are coated with a non-reflective film.

In the assembly of such an optical semiconductor device module, after fixing the optical semiconductor element 12 on the support plate 33 via the submount 34, the output light from the optical fiber 5 supported by the guide 31 is supplied. Finely adjust the lenses 39, 40 and the tip of the optical fiber 5 while monitoring, and assemble the optical coupling system by connecting each part by soldering or laser welding in a state where the optical coupling to the optical fiber 5 is maximized. finish. Here, in order to suppress reflection, a measure is often taken in which the end face of the optical fiber is inclined several degrees with respect to the optical axis. After that, the entire optical coupling system is hermetically sealed in the package 30 in a nitrogen atmosphere or the like.

[0021]

The conventional optical semiconductor device module can modulate the optical output by directly applying the electrical modulation signal to the optical semiconductor element. This modulated optical signal is transmitted through the optical fiber and carries the signal. Normally, if this modulation and transmission are achieved, the optical semiconductor device module can be applied to a device or an optical transmission system.

However, if the semiconductor laser (optical semiconductor element) has reflected return light from each optical component, the noise of the semiconductor laser increases, and sufficient transmission quality can be ensured in an actual device or optical transmission system. Becomes difficult.

In the conventional optical semiconductor device module, the antireflection film is provided on the surface of the optical component such as the lens surface or the end surface of the optical fiber. However, simply providing the antireflection film suppresses the reflected light returning to the semiconductor laser. Can not do it.

In the conventional optical semiconductor device module, the work of coating a non-reflective film on the optical parts, the troublesome assembling work such as the optical axis adjustment and the soldering or the laser welding is required, and the assembling time becomes long. Therefore, it is difficult to reduce the product cost.

On the other hand, even when the optical semiconductor element is a light receiving element, the reflected light adversely affects the transmission quality and the complexity of assembly is the same as that of the light emitting element. That is, the monitoring at the time of optical coupling is performed while the light is incident from the outside through the optical fiber and the output of the light receiving element is monitored.
However, even if there is reflected light, it becomes difficult to distinguish it from the actual signal, and the reliability of the monitor becomes low.

An object of the present invention is to provide an optical semiconductor device module in which reflected light is less likely to be generated on the optical component surface.

Another object of the present invention is to provide an optical semiconductor device module which does not require a lens for optical coupling.

Another object of the present invention is to provide an optical semiconductor device module in which an optical coupling portion and optical parts can be easily fixed.

Another object of the present invention is to provide an optical semiconductor device module in which the assembly time is shortened.

Another object of the present invention is to provide an optical semiconductor device module which can reduce the manufacturing cost.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0032]

The outline of the representative ones of the inventions disclosed in the present application will be briefly described as follows.

(1) Package and optical semiconductor element (for example, semiconductor laser) arranged in the package
And an optical semiconductor device module having an optical fiber extending over the inside and outside of the package and having one end optically coupled to the semiconductor laser, wherein the package is adapted to light transmitted through the optical fiber. Transparent and is formed of a resin having a refractive index substantially the same as the refractive index of the portion of the optical fiber through which light passes, and the space between the semiconductor laser and the optical coupling surface of the optical fiber is filled with the transparent resin. The fiber and the semiconductor laser are integrated by the resin. The resin has a refractive index within ± 10% of the refractive index of the portion (core) through which the light of the optical fiber passes.

(2) Package and optical semiconductor element (for example, semiconductor laser) arranged in the package
And an optical fiber extending inside and outside the package, and at least one optical component (for example, an optical waveguide) arranged between the semiconductor laser and the optical fiber. And an optical semiconductor device module in which an optical fiber is optically coupled, wherein the package is transparent to light transmitted through the optical fiber and the optical waveguide, and a portion through which the light of the optical fiber and the optical waveguide passes ( Core) is formed of a resin having a refractive index substantially the same as that of the core), and the spaces between the optical coupling surfaces are filled with the resin, and the optical fiber, the optical waveguide, and the semiconductor laser are integrated by the resin. ing. The resin has a refractive index within ± 10% of the refractive index of the portion of the optical fiber and the optical waveguide through which light passes.

[0035]

According to the above-mentioned means (1), since the emitting surface of the semiconductor laser and the one end surface of the optical fiber are optically coupled by the resin whose refractive index is substantially the same as the refractive index of the core of the optical fiber, the semiconductor laser is connected. The reflected light of is extremely small.

According to the above-mentioned means (1), the transparent resin having a refractive index substantially the same as the refractive index of the core of the optical fiber is filled between the emitting surface of the semiconductor laser and the one end surface of the optical fiber. . If a resin that substantially matches the core of the optical fiber is used between the optical coupling surfaces, the spread of the laser light (radiated light) from the semiconductor laser becomes as small as about 2/3 of that in air.
High optical coupling efficiency can be obtained. As a result, it is not necessary to use a lens, and the number of parts and the number of assembling steps can be reduced.

According to the above-mentioned means (1), the optical fiber, the ferrule supporting the optical fiber, the semiconductor laser, the supporting portion supporting the semiconductor laser and the like are integrated at the same time when the package is formed. Will be easier. As a result, the assembly time can be shortened.

According to the means (1), the cost of the optical semiconductor device module can be reduced by reducing the number of parts and assembling time.

According to the above-mentioned means (2), even in the structure having the optical waveguide between the semiconductor laser and the optical fiber, as in the case of the above-mentioned means (1), the reflected return light is reduced and the lens is not damaged. Use and manufacturing costs can be reduced.

[0040]

Embodiments of the present invention will be described below in detail with reference to the drawings.

In all the drawings for explaining the embodiments, parts having the same function are designated by the same reference numerals, and the repeated description thereof will be omitted.

(Embodiment 1) FIG. 1 is a sectional view of an optical semiconductor device module which is an embodiment (Embodiment 1) of the present invention.
2 is an enlarged plan view of the heat sink in the optical semiconductor device module of the first embodiment, and FIG. 3 is an enlarged side view of the heat sink.

The optical semiconductor device module according to the first embodiment is
It has a stem (CD stem) 10 having a support portion 50 protruding in the central portion of one surface. A plurality of electric input / output terminals 9 are attached to the stem 10.

A heat sink 51 made of a silicon plate is fixed to the side surface of the support portion 50. As shown in FIGS. 2 and 3, the heat sink 51 has a V surface on the main surface.
A groove 52 is provided.

The V-shaped groove 52 is provided from one end side of the heat sink 51 to a middle portion. The main surface portion of the heat sink 51, which is an extension of the V-shaped groove 52, serves as a fixed region 53 to which the optical semiconductor element 12 made of a semiconductor laser is fixed. The optical semiconductor element 12 is fixed on the fixing region 53 by soldering, and the tip portion of the cylindrical optical fiber 5 is inserted into the V-shaped groove 52. By inserting the cylindrical optical fiber 5 into the V-shaped groove 52, optical coupling between the optical semiconductor element 12 fixed to the heat sink 51 and the optical fiber 5 can be automatically performed.

The tip surface of the optical fiber 5 and the optical semiconductor element 12
The distance between the light emitting surface and the light emitting surface is determined when the optical semiconductor element 12 is fixed to the heat sink 51. That is, since the distance between the emission surface of the optical semiconductor element 12 and the inner end surface of the V-shaped groove 52 is determined by fixing the optical semiconductor element 12 to the heat sink 51, when the optical fiber 5 is inserted into the V-shaped groove 52. By inserting the optical fiber 5 so as to be pressed against the inner end face of the V-shaped groove 52, the distance between the tip end face of the optical fiber 5 and the emission face of the optical semiconductor element 12 is determined.

A monitor photodiode 16 for receiving the rear light of the laser beam 17 emitted from the optical semiconductor element 12 fixed to the main surface of the heat sink 51 is fixed to the main surface of the stem 10 by soldering or the like. There is.

The optical fiber 5 extends from the optical fiber cord 4 and is exposed by peeling the end of the optical fiber cord 4 over a certain length.
The optical fiber 5 is supported by the ferrule 3 that supports up to the tip of the optical fiber cord 4.

The portion extending from the stem 10 to the ferrule 3 is covered with a transparent resin 54. The resin 54 covers the optical semiconductor element 12, the monitor photodiode 16, the inner end portion of the optical fiber 5 and the like.
It is also 5.

The resin 54 becomes a transparent body and is filled between one emission surface of the optical semiconductor element 12 and the front end surface of the optical fiber 5, and at the same time, the other emission surface of the optical semiconductor element 12 and the monitor photodiode 16. It will be filled between the light receiving surfaces.

As the transparent resin, epoxy resin or silicone resin having a refractive index within ± 10% of the refractive index (about 1.5) of the core of the optical fiber is used.

Within this range, the amount of light reflected back to the semiconductor laser is about 0.01% or less, and noise generation of the semiconductor laser due to coherence collapse generation (having a threshold value for the amount of returned light) is suppressed. . (For example, Kurosaki, Hirono, Fukuda, IEEE Photonocs Technology Letter, v
ol. 6, No. 8, p. 900, 1994).

Here, the reflected return light to the semiconductor laser will be described.

Considering the end face of the optical fiber perpendicular to the incident light, which is considered to generate the most reflected return light with respect to the emission face of the semiconductor laser, the reflected light generated at the end face of the optical fiber is the semiconductor laser ( The rate of returning to the optical semiconductor element, that is, the coupling efficiency η is given by the following equation.

[0055]

Η = A (1-R ₁ ) R ₂

[0056]

R ₁ = (n _laser −n _mold ) ² / (n _laser + n _mold ) ²

[0057]

R ₂ = (n _fiber −n _mold ) ² / (n _fiber + n _mold ) ² Here, n _laser is the refractive index of the medium constituting the semiconductor laser, and A is the end face (emission face) of the semiconductor laser. It is a coefficient determined by the distance between the end faces of the optical fiber, the wavelength of laser light, and the spot size.

Therefore, in order to reduce the amount of light reflected back to the semiconductor laser, it suffices to select the refractive index n _{mold of the} resin and reduce R ₂ , and thus the refractive index n of the resin.
_By setting the _mold to be about the same as the refractive index n _fiber of the optical fiber, the reflected return light becomes small, and by making it the same, the reflected return light can be eliminated.

Further, when a resin which is substantially aligned with the core of the optical fiber is used between the optical coupling surfaces, the spread of the laser light (radiated light) from the semiconductor laser becomes as small as about 2/3 of that in the air. Even without using, the coupling efficiency with the optical fiber is improved compared to the conventional one without a lens. As a result, it is not necessary to use a lens, and the number of parts and the number of assembling steps can be reduced.

Next, a method of assembling the optical semiconductor device module of the first embodiment will be described. First, the monitor photodiode 16 is fixed to the stem 10. Further, the heat sink 51 having the optical semiconductor element 12 made of a semiconductor laser fixed to the main surface is fixed to the side surface of the support portion 50 of the stem 10. The monitor photodiode 16, the optical semiconductor element 12, and the heat sink 51 are fixed by, for example, AuSn solder (Au: 80% / S) having a melting point of about 280 ° C.
n: 20%).

Next, the tip of the optical fiber 5 having the ferrule 3 attached thereto is attached to the V-shaped groove 5 of the heat sink 51.
2 and press the tip against the abutting portion of the V-shaped groove 52. As a result, the optical axes of the emitting surface of the semiconductor laser and the core of the optical fiber are automatically adjusted with high accuracy.

The optical fiber 5 may have any structure such as one having a spherical tip (spherical tip), one having a slanted tip surface, or one having a tip perpendicular to the optical axis.

Next, a package 55 is formed by covering the optical fiber 5 with the optical axis thereof covered with a transparent resin 54. Although not shown, this resin sealing work is performed using a mold. The resin 54 covers the optical semiconductor element 12 and the optical fiber 5, and also the stem 10 and the optical semiconductor element 1
2. The optical fiber 5 and the ferrule 3 are integrated.

In the resin encapsulation, the transparent resin is used as described above, but since the curing temperature of the resin is 250 ° C. or less, it is used for fixing the optical semiconductor element 12, the heat sink 51 and the monitor photodiode 16. Melting point of the AuSn solder (Au: 80% / Sn: 20%) (approx. 280
C.), the module does not deteriorate due to instability of the solder during resin encapsulation.

The fixing of the optical fiber while the optical coupling is being performed at the time of resin sealing is sure to be performed without damaging the optical coupling because the optical fiber 5 is inserted into the V-shaped groove 52 of the heat sink 51 and is stable. You can do it.

In the optical semiconductor device module of the present embodiment, as a result of filling the transparent resin between the optical coupling surfaces, it is possible to reduce the reflected return light.

In the optical semiconductor device module of this embodiment, as a result of filling the transparent resin between the optical coupling surfaces, a high optical coupling efficiency can be obtained without using a lens.

The optical semiconductor device module of this embodiment can obtain a high optical coupling efficiency without using a lens, and can reduce the assembly cost because the number of parts is reduced.

In the optical semiconductor device module of this embodiment,
When the package 55 is formed of the transparent resin 54, a space between one end face of the optical fiber 5 and the emission surface of the optical semiconductor element (semiconductor laser) 12 is filled with the transparent resin to achieve high optical coupling. Since the ferrule 3 that supports the optical fiber 5, the heat sink 51 that supports the optical semiconductor element 12, the support portion 50, and the like can be integrated, the assembly is facilitated, the number of steps can be reduced, and the assembly time can be shortened.

The manufacturing technique of the optical semiconductor device module as described above is applied to a buried type InGaAsP / I of 1.3 μm band.
When applied to the nP MQW Fabry-Perot laser,
Vertically cut single-mode optical fiber with a core diameter of 10 μm is used, and the distance between the semiconductor laser and the optical fiber end is approximately 10 μm.
In the case of, there is no increase in the intensity noise of the semiconductor laser when the resin is present, and for example, −1 at the frequency of 1 MHz.
A noise level of 40 dB / Hz or less was obtained.

In the absence of resin, the intensity noise of the semiconductor laser increased, and a noise level of -120 dB / Hz or higher often appeared.

Further, the spread of the radiated light due to the diffraction phenomenon of the semiconductor laser is about 2/3 in the resin having the refractive index of about 1.5 as compared with the case of the air in which the refractive index is 1. The light coupling efficiency was also improved, and a coupling efficiency of about −10 dB was easily obtained.

Further, the time required for assembling is shortened to about 1/10 as compared with the conventional hermetic sealing, and the rate is mainly limited by the time required for adjusting the distance between the end face of the optical fiber and the emitting surface of the semiconductor laser.

Furthermore, these resin sealing modules are
When electricity was applied at a fiber light output of −3 dB in an atmosphere of 0 ° C. (in the air), there was no noticeable deterioration. It was impossible with the prior art to perform hermetic sealing in a fiber batting state without using these lenses.

Further, the end face (or the whole) of the semiconductor laser is coated with a dielectric film such as a silicon nitride film to control the end face reflectance of the semiconductor laser and to further improve environment resistance such as moisture resistance. Can also be implemented effectively,
Further long-term stability could be obtained.

On the other hand, when a light emitting diode as a light emitting element was incorporated as an optical semiconductor element, resin sealing could be easily performed. In the surface emitting type light emitting diode, the optical axis adjustment was almost unnecessary.

In the first embodiment, the lens is not included between the optical fiber and the semiconductor laser, but the assembly process is slightly complicated. However, the structure is such that the lens can be manufactured and the coupling of light is performed. Was improved by at least 3 dB or more.

(Embodiment 2) FIG. 4 is a sectional view of an optical semiconductor device module which is another embodiment (Embodiment 2) of the present invention.

The second embodiment is an optical semiconductor device module on the receiving side in which a light receiving element is incorporated as an optical semiconductor element.
The optical semiconductor device module of the second embodiment is the same as that of the first embodiment.
4, the heat sink 51 fixed to the support portion 50 of the stem 10 supports the entire optical fiber 5. That is, although not shown, the main surface of the heat sink 51 has
Similar to the heat sink 51, a V-shaped groove is provided.
The V-shaped groove is provided over the entire length of the heat sink 51 (the V-shaped groove is provided over the entire length of the heat sink, but this is different from the case of the semiconductor laser in that the distance between the optical fiber and the semiconductor laser is Therefore, the V-shaped groove 52 may have a structure halfway as in the first embodiment).

The tip of the optical fiber 5 supported by the heat sink 51 faces the main surface of the stem 10.

The stem 10 on the extension of the optical fiber 5
A light receiving element 60 is fixed on the main surface of the optical fiber 5
It is designed to receive the light transmitted by. The light receiving element 60 is, for example, a 1.3 μm band surface emitting type light receiving element (photodiode) having a light receiving diameter of 30 μm.
Is.

The optical semiconductor device module according to the second embodiment is
In the assembly, the light receiving element 60 and the heat sink 5
1 is fixed by AuSn solder (Au: 80% / Sn: 20%).

Next, the optical fiber 5 with its tip cut vertically is brought close to the light receiving element 60 along the V-shaped groove formed on the heat sink 51, and then fixed (sealed) with the transparent resin 54. At this time, the optical axis alignment can be adjusted only by observing an image with a microscope or the like. Of course, it is also possible to adjust the optical axis while monitoring the light receiving current in the light receiving element 60.

The resin 54 is a resin having a refractive index within ± 10% with respect to the refractive index of the core of the optical fiber 5, as in the case of the first embodiment.

The optical semiconductor device module according to the second embodiment is
Since the transparent resin 54 is filled between the optical coupling surfaces of the light receiving element 60 and the optical fiber 5, the optical fiber 5
The amount of reflected return light generated at one end of the optical receiver or the light receiving surface of the light receiving element 60 is small, and the optical transmission system does not suffer any adverse effects due to the reflected return light.

Further, in the optical semiconductor device module according to the second embodiment, since the respective parts are integrated by the resin 54 when forming the package 55, the assembling is facilitated and the assembling time can be shortened.

(Embodiment 3) FIG. 5 is a sectional view of an optical semiconductor device module according to another embodiment (Embodiment 3) of the present invention.

The optical semiconductor device module of the third embodiment is
Optical semiconductor element 12 composed of semiconductor laser and optical fiber 5
An optical waveguide 65 as an optical component is interposed between the optical waveguide 65, the laser light 17 is coupled to the light-transmitting portion (core) of the optical waveguide 65, and the output light (laser light 17) of the optical waveguide 65 is converted into light. The optical signal is transmitted over a long distance by being coupled to the fiber 5.

The appearance of the optical semiconductor device module is
A plate-shaped stem 10, a resin 54 formed of a rectangular body covering the main surface side of the stem 10, a plurality of electric input / output terminals 9 attached to the stem 10, and a guide projecting from the right end surface of the resin 54. 31 and an optical fiber cord 4 protruding from the guide 31. The package 55 is formed by the stem 10 and the resin 54.

The resin 54 has a refractive index within ± 10% of the refractive index of the core of the optical waveguide 65 and the core of the optical fiber 5.

An optical waveguide 65 is provided on the main surface of the stem 10. The optical waveguide 65 is, for example, a quartz optical waveguide.

On the stem 10 on the left side of the optical waveguide 65, an optical semiconductor element 12 made of a semiconductor laser is fixed via a submount 34. The optical semiconductor element 12 emits laser light 17 from the left and right surfaces. One laser light 1
7 passes through the core of the optical waveguide 65 and is optically coupled to one end of the optical fiber 5 of the optical fiber cord 4 supported by the guide 31.

The laser light 17 traveling to the left (rear light)
Is received by the monitoring photodiode 16 fixed to the side surface of the support 35 of the stem 10.

The optical semiconductor device module according to the third embodiment is
In the assembly (manufacturing), the guide 3 for supporting the optical fiber 5 on the main surface of the stem 10 on which the optical waveguide 65 is formed.
1, a submount 34 to which the optical semiconductor element 12 is fixed, and a support 35 to which the monitor photodiode 16 is fixed are fixed.

At this time of fixing, the optical axes of the optical semiconductor element 12, the optical waveguide 65 and the optical fiber 5 are aligned,
It is fixed in a state where the optical axes match (positional relationship in which the output light of the optical fiber 5 is maximized). After that, the main surface side of the stem 10 is sealed with the transparent resin 54. Resin 5
No. 4 has a refractive index within ± 10% with respect to the refractive index of the core of the optical fiber 5, as in the first and second embodiments.

Since the transparent resin 54 is filled between the optical coupling surfaces of the optical semiconductor element 12, the optical waveguide 65, the optical fiber 5, and the monitor photodiode 16, the same as in the case of the first embodiment. In addition, while having high optical coupling, it becomes difficult for reflected reflection light to be generated on the surface of each optical component.

(Embodiment 4) FIG. 6 is a sectional view of an optical semiconductor device module which is another embodiment (Embodiment 4) of the present invention. The fourth embodiment is the optical semiconductor device module of the third embodiment in which a part of the main surface of the stem 10 is sealed with a resin 54. That is, the resin 54 includes the monitoring photodiode 16, the support 35 that supports the monitoring photodiode 16, the optical semiconductor element 12, the submount 34 that supports the optical semiconductor element 12, and the optical waveguide 65.
Of the optical semiconductor element 12 is covered.

The resin 54 has a refractive index within ± 10% with respect to the refractive index of the core of the optical waveguide 65 and the core of the optical fiber 5.

Also in the optical semiconductor device module of the fourth embodiment, the transparent resin 54 is filled between the optical coupling surfaces of the optical semiconductor element 12, the optical waveguide 65 and the monitor photodiode 16 in each component. Therefore, as in the case of Example 1, while having high optical coupling,
The generation of reflected return light on the surface of each optical component is less likely to occur.

In the optical semiconductor device modules of the third and fourth embodiments, if the optical waveguide is a so-called Matsuhatsuender type external modulator, an electric signal is applied to this optical waveguide to modulate the optical signal. Done.

If the optical waveguide is branched into a plurality of parts on the way, the optical waveguide has a plurality of output ends, and a plurality of optical fibers can be spatially coupled.

In these systems, reflection of laser light occurs at the incident end of the optical waveguide and the optical fiber, and noise increases when returning to the semiconductor laser. However, between the optical semiconductor element 12 and the optical waveguide 65 and between the optical waveguide 65 and the optical fiber 5, a resin having a refractive index within ± 10% of the refractive index of the core of the optical waveguide 65 and the core of the optical fiber 5 is used. Since 54 is filled, generation of reflected light can be suppressed. Further, since the optical coupling rate is high, the lens is unnecessary.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

[0104]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

(1) Since the emitting surface of the semiconductor laser and the one end surface of the optical fiber are optically coupled by the resin whose refractive index is substantially the same as the refractive index of the core of the optical fiber, the reflected light returning to the semiconductor laser is extremely small. , The noise is less likely to occur,
It is possible to provide a highly reliable optical semiconductor device module.

(2) A transparent resin having a refractive index substantially the same as the refractive index of the core of the optical fiber is filled between the emitting surface of the semiconductor laser and one end surface of the optical fiber. If you use a resin that is almost the same as the core of the optical fiber,
Since the spread of the laser light (radiation light) from the semiconductor laser is as small as about 2/3 of that in the air, high optical coupling efficiency can be obtained.

(3) Since high optical coupling efficiency can be obtained without using a lens, the number of parts and the number of assembling steps can be reduced.

(4) When the package is formed of resin, each component is integrated, so that the number of assembling steps can be reduced.

(5) An inexpensive optical semiconductor device module can be provided because the number of parts is reduced and the assembly time is reduced.

(6) Even with a structure in which an optical component such as an optical waveguide is interposed between the optical fiber and the optical semiconductor element, high optical coupling can be obtained without using a lens, and
Generation of reflected light can be suppressed.

(7) The optical semiconductor device module can shorten the time in the assembling process by about 1/10 of that of the conventional hermetically sealed module, and has a characteristic comparable to that of the conventional module in that no reflected light is generated. It can be obtained, and it can be made economical within the range of practical use.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an optical semiconductor device module that is an embodiment (Embodiment 1) of the present invention.

FIG. 2 is an enlarged plan view of a heat sink in the optical semiconductor device module according to the first embodiment.

FIG. 3 is an enlarged side view of a heat sink in the optical semiconductor device module according to the first embodiment.

FIG. 4 is a sectional view of an optical semiconductor device module which is another embodiment (Embodiment 2) of the present invention.

FIG. 5 is a sectional view of an optical semiconductor device module which is another embodiment (Embodiment 3) of the present invention.

FIG. 6 is a sectional view of an optical semiconductor device module which is another embodiment (Embodiment 4) of the present invention.

FIG. 7 is a sectional view of a conventional coaxial optical semiconductor device module.

FIG. 8 is a cross-sectional view of a conventional box-type optical semiconductor device module.

[Explanation of symbols]

1 ... Semiconductor laser device, 2 ... Combined body, 3 ... Ferrule,
5 ... Optical fiber, 10 ... Stem, 11 ... Cap, 12
... Opto-semiconductor element, 16 ... Monitor photodiode, 1
7 ... Laser light, 23 ... Lens, 30 ... Package, 36
... Thermistor, 39, 40 ... Lens, 50 ... Support part, 5
1 ... Heat sink, 52 ... V-shaped groove, 54 ... Resin, 55 ...
Package, 60 ... Light receiving element, 65 ... Optical waveguide.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Koji Sato 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Shunichi Higashino 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation

Claims (6)

[Claims] 1. An optical semiconductor device module having an optical semiconductor element and an optical fiber optically coupled to the optical semiconductor element, wherein an optical coupling surface between the optical fiber and the optical semiconductor element is provided. An optical semiconductor device module, characterized in that it is filled with a resin that is transparent to the light transmitted through the optical fiber and has a refractive index substantially the same as the refractive index of the portion of the optical fiber through which the light passes. 2. A light having a package, an optical semiconductor element disposed in the package, and an optical fiber extending inside and outside the package and having one end optically coupled to the optical semiconductor element. A semiconductor device module,
The package is formed of a resin that is transparent to light that passes through the optical fiber and has a refractive index that is substantially the same as the refractive index of the portion of the optical fiber through which light passes. An optical semiconductor device module, wherein a space between the coupling surfaces is filled with the transparent resin, and the optical fiber and the optical semiconductor element are integrated by the resin. 3. The optical semiconductor device module according to claim 2, wherein the resin has a refractive index within ± 10% of a refractive index of a portion of the optical fiber through which light passes. 4. An optical semiconductor device module in which at least one optical component is disposed between the optical semiconductor element and the front end surface of the optical fiber, and the optical semiconductor element, the optical component, and the optical fiber are optically coupled. A transparent resin having a refractive index substantially the same as the refractive index of the light passing portion of the optical fiber and the optical component between the optical coupling surfaces of the optical semiconductor element, the optical component, and the optical fiber. An optical semiconductor device module characterized by being filled with. 5. A package, an optical semiconductor element provided in the package, an optical fiber extending inside and outside the package, and at least one provided between the optical semiconductor element and the optical fiber. An optical semiconductor device module having two optical components, wherein the optical semiconductor element, the optical component, and the optical fiber are optically coupled to each other, and the package is provided for the light passing through the optical fiber and the optical component. Transparent and formed of a resin having a refractive index that is substantially the same as the refractive index of the portion of the optical fiber through which the light passes, and the spaces between the optical coupling surfaces are filled with the resin. An optical semiconductor device module, wherein the component and the optical semiconductor element are integrated by the resin. 6. The optical semiconductor according to claim 4 or 5, wherein the resin has a refractive index within ± 10% of a refractive index of a portion of the optical fiber and the optical component through which light passes. Equipment module.