JPH0318806A - Semiconductor laser module - Google Patents

Abstract

PURPOSE:To accurately position the above module with high accuracy of submicron order at a high yield by specifying the center line average surface roughness of the adhering surfaces of 1st and 2nd fixing blocks. CONSTITUTION:The center line average surface roughenes Ha on the adhering surfaces of the 1st fixing block and the 2nd fixing block is specified to 0.3mum<Ha<6.0mum. The average surface roughness Ha of the adhering surfaces of the 1st, 2nd fixing blocks 3, 4 is maintained in the specified range in such a manner, by which adhesives 5, 5' infiltering the spacing between the two fixing blocks 3, 4 are prevented from acting as a lubricant. Sufficient friction force is obtd. when the two fixing blocks 3, 4 are brought into pressurized contact with each other. The generation of the misregistration at the time of the shrinkage of the adhesives 5, 5' on curing is prevented in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fiber-attached semiconductor laser module used as a light source in the fields of optical communications and optical information processing.

[Conventional technology]

As a semiconductor laser module with a fiber, a module using a tipped optical fiber 1 as shown in FIG. 2 is being considered (Japanese Patent Application No. 63-309879). Since a high coupling efficiency of 2 to 4 dB can be obtained with LD) 2, by using this, an inexpensive, small-sized, high-performance fiber-attached semiconductor laser module can be realized. However, the method using the optical fiber 1 described above has a problem in that high precision is required for positioning and fixing. Figures 3 and 4 show the oscillation wavelength 1.
．． 3-1 InGaAsP semiconductor laser 2 with full angle at half maximum (FWHM) θ (X direction in Figure 2) and θη (Y direction in Figure 2) of 30 degrees and 23 degrees, respectively, and tip sphere radius R = 1
FIG. 3 is a diagram showing the distance dependence of the coupling efficiency with the 0- tip spherical optical fiber 1 (single mode). Figure 3 shows the optical axis direction (2 axes)
is the distance dependence of the semiconductor laser 2 and the tipped fiber 1.
Maximum coupling efficiency (56%) at a distance of Δz = 11 gm.

2.5 dB) was obtained, and it can be seen from FIG. 3 that the 1 dB tolerance (1 dB deterioration allowable positional deviation amount) is ±4.5-. On the other hand, FIG. 4 shows the distance dependence of the coupling efficiency in the direction perpendicular to the optical axis (X+y direction in FIG. 2) when Δz = 11 ufa. As is clear from the figure, 1dB
The tolerance is ±0.8%.

A 1 dB tolerance of ±4.5 p in the optical axis direction can be sufficiently achieved by positioning and fixing using solder, adhesive, welding, or the like. However, since submicron (±0.8 IRa) accuracy is required in the direction perpendicular to the optical axis, the conventional example shown in FIG. 2 was devised as follows. That is, as shown in FIG. 2, a first fixing block 3 integrated with a housing 7 is provided in the vicinity of the semiconductor laser 2, and on the other hand, a portion near the lens portion at the tip is provided on the side of the spherical fiber 1. .

A second fixing block 4 bonded with an adhesive 5' is provided in the optical fiber insertion fixing hole. After alignment work,
The second fixing block 4 is crimped and fixed to the first fixing block 3 by pressing the bulbous fiber 1 in two directions in the figure,
The rear surface fixing blocks were fixed with adhesive 5.

That is, the frictional force between the blocks 3 and 4 is intended to prevent positional displacement caused by hardening and shrinkage of the adhesive during position fixing work. The second optical fiber holding section 6 is for preventing external force from outside the system from reaching the tip lens section via the fiber.

[Problem to be solved by the invention]

The above conventional technology has the following problems. That is, as shown in FIG. 5, after the second fixing block 4 is fixed to the first fixing block 3 by pressure, when adhesive 5 is applied between both blocks, the adhesive 5 is applied to both blocks due to surface tension. 3.4, which acts as a lubricant and significantly reduces the frictional force between the two blocks. Therefore, misalignment is likely to occur during the process of thinning of the adhesive, resulting in poor product yield.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fiber-attached semiconductor laser module that is inexpensive, compact, and high-performance, in which positioning can be performed with high precision between a tipped optical fiber and a semiconductor laser.

[Means to solve the problem]

The above purpose is for the adhesive surface between the first fixing block 3 and the second fixing block 4. Center line average surface roughness Ha
This is achieved by setting 0.3x<Ha<6.0Ilfa.

[Effect]

In the conventional technology, the bonding surfaces of the first fixing block and the second fixing block were finished flat and fixed by pressure, and then bonded, but the frictional force between the first and second fixing blocks However, in the present invention, since the average surface roughness of the bonding surfaces of the first and second fixing blocks is maintained within a certain range, both fixing blocks Adhesive that has penetrated into the gaps between the blocks does not act as a lubricant, and sufficient frictional force is obtained by pressing the two fixing blocks together, thereby preventing positional shift when the adhesive hardens and shrinks. I can do it.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view showing an embodiment of a semiconductor laser module according to the present invention. First, copper-tungsten (Cu
10%-W90%) alloy square bar is cut into the first fixing block 3 and the second
After processing the optical fiber fixing part 6 into a structure in which the optical fiber fixing part 6 was integrated, parts other than the adhesive surface of the first fixing block 3 were plated with gold to prepare the casing 7. On the other hand, ultrasonic processing or CO□ was applied to a 300.1/II thick quartz plate.
A second fixing block 4 in which a hole for holding an optical fiber having a diameter of 150 to 200 holes was formed was manufactured by laser processing.

Next, the adhesive surfaces of the first and second fixing blocks were sprayed with diamond powder having a particle size of 43,000 to 4,000 to obtain a desired roughness. Next, oscillation wavelength 1.3. , full width at half maximum of radiation (, F W HM ) θ
An InGaAsP laser 2 having angles of 30 degrees and 23 degrees, respectively, was installed at a predetermined portion of the casing 7 via a heat sink 2' as shown in FIG. Next, the laser 2 is placed on a fine movement table parallel to the direction of gravity with its light emitting surface facing upward, and a second fixing block 4 for holding the optical fiber is placed on the adhesive surface of the first fixing block 3. A quartz plate with holes was placed with the adhesive side down. Next, the tip fiber was placed on the fine movement table parallel to the direction of gravity.

Upward force Epoxy resin or ultraviolet curing resin was injected and cured, and the tip fiber 1 and the second fixing block 4 were bonded together. Next, after adjusting the coupling efficiency to the maximum again, the tip fiber 1 was displaced in the negative direction of the two axes, and the second fixing block 4 was crimped onto the first fixing block 3.

Next, epoxy resin or ultraviolet curing resin is injected and hardened between both fixing blocks 3 and 4, and the semiconductor laser 2
and the positional relationship of the tip fiber 1 was fixed. Finally, the second
An adhesive was injected into the optical fiber fixing portion 6 and cured to complete a fiber-attached semiconductor laser module.

Based on the above process, 10 types of modules were manufactured in which the surface roughness of the adhesive surfaces of the first and second fixing blocks was changed, and changes in the coupling efficiency between the semiconductor laser 2 and the spherical fiber 1 were investigated. The centerline average roughness Ha of the adhesive surfaces of the 10 types of modules is as follows. Ha=0.0
1.0.3゜0.5.0.9, 2.0.3.0.4.0
．． 5.0.6.0.7.0 m (for the center line average roughness, refer to "Mechanical Optics Handbook" written and published by Japan Society of Mechanical Engineers, June 15, 1970, PP, 17-176). As a result, the center line average roughness Ha of the adhesive surface exceeded 0.3 and was 0.6.
There was no change in binding efficiency for samples with less than Rflllll. On the other hand, when Ha was less than 0.3-, there was no decrease in bonding efficiency in the process of press-fixing both fixing blocks, but in the process of injecting and curing the adhesive between both fixing blocks, Ha was 0.3- 5il reduction in coupling efficiency of 0.9dB
I'll be disappointed. In addition, if Ha exceeds 6-, 0.3 to 1.5 dB in the crimping process of both fixing blocks.
However, there was no decrease in bonding efficiency during the adhesive injection curing process. From the above results, if the surface roughness Ha of the adhesive surface is set between 0.3 and 0.6-,
It was found that non-displacement fixation can be achieved.

〔Effect of the invention〕

As described above, the semiconductor laser module according to the present invention has
A semiconductor laser installed at a predetermined position of a housing, a tipped optical fiber having a lens portion at the tip and optically coupled to the semiconductor laser, and an adhesive surface perpendicular to the optical axis near the semiconductor laser. and a first fixing block installed so that the adhesive surface is located a predetermined distance ahead of the light emitting surface of the semiconductor laser, an optical fiber insertion fixing hole parallel to the optical axis, and a fixing hole perpendicular to the optical axis. a second adhesive surface, the first receiving surface is fixed to the first fixing block, and the optical fiber insertion and fixing hole holds the optical fiber in the vicinity of the lens portion with an adhesive; A semiconductor laser module having a first optical fiber holding part consisting of a fixing block, and a second optical fiber holding part provided a predetermined distance ahead of the first optical fiber holding part. Since the center line average surface roughness Ha of the adhesive surface of the second fixing block is 0.3 m<Ha<6.0 m, high-precision positioning with submicron precision can be achieved with high yield. can. In addition, since the area for the adhesive between the first and second fixing blocks increases, the adhesive strength increases and reliability can be improved, making it possible to obtain a high-performance and inexpensive fiber-attached semiconductor laser module. be.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of a semiconductor laser module according to the present invention, FIG. 2 is a perspective view showing a conventional semiconductor laser module, and FIG. 3 is a diagram showing the coupling efficiency of the laser of the present invention and a tipped fiber. Figure 4 shows the distance dependence in the direction parallel to the axis. Figure 4 shows the distance dependence of the coupling efficiency between the semiconductor laser and the tip fiber in the direction perpendicular to the optical axis. Figure 5 shows the adhesion in the conventional module. FIG. 3 is a diagram showing the state of application of the agent. 1... Tip optical fiber 2... Semiconductor laser 3.
...First fixing block 4...Second fixing block 5.5'...Adhesive 6...Second optical fiber holding part 7...Casing

Claims (1)

[Scope of Claims] 1. A semiconductor laser installed at a predetermined position in a case, a tipped optical fiber having a lens portion at the tip and optically coupled to the semiconductor laser, and an optical fiber in the vicinity of the semiconductor laser. a first fixing block having an adhesive surface perpendicular to the axis and installed so that the adhesive surface is located a predetermined distance ahead of the light emitting surface of the semiconductor laser; and an optical fiber parallel to the optical axis. An insertion fixing hole and an adhesive surface perpendicular to the optical axis are provided, and the adhesive surface is fixed to the first fixing block, and the optical fiber insertion fixing hole is provided with an adhesive near the lens portion of the tip optical fiber. A semiconductor laser having a first optical fiber holding part made up of a second fixing block held therein, and a second optical fiber holding part provided a predetermined distance ahead of the first optical fiber holding part. A semiconductor laser module characterized in that the center line average surface roughness Ha of the first and second fixing block adhesive surfaces satisfies the following: 0.3 μm<Ha<6.0 μm.