JPH0627346A - Assembling method for optical device - Google Patents

Abstract

PURPOSE:To provide an assembling method for an optical device with high optical coupling capability by welding the abutting plane of an optical component after applying smoothing finishing to it. CONSTITUTION:The abutting plane of the optical component is spot-welded after it is ground to a smooth plane with surface roughness of <=6.3S (JISB0601) in the assembling method for the optical device in which prescribed planes of the optical components 4, 5, and 6 which comprise the optical device are abutted on each other and spot-welding is applied to the outer periphery of the abutting plane. Since the abutting planes of the optical components 4, 5, and 6 are formed to smooth, solidification contraction after the spot welding is generated uniformly extending over the whole abutting plane, and no deviation of optical axes among the optical components 4, 5, and 6 occurs.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of assembling an optical device having an excellent optical coupling property.

[0002]

2. Description of the Related Art An optical device is a device in which an optical fiber is optically coupled to an optical waveguide or a semiconductor light emitting / receiving element directly or through a lens, and this optical device is assembled by a predetermined optical component such as the optical waveguide. The surfaces were finished to have a surface roughness of 25S to 100S (JIS B 0601) and brought into contact with each other, and the outer periphery of the contact surfaces was spot-welded with a laser.

[0003]

However, in the optical device assembled by the laser welding method as described above,
There is a problem that the optical axes of the optical components are often deviated from each other, and an optical device excellent in optical coupling cannot be stably manufactured.

[0004]

The present invention has conducted intensive studies in view of such a situation, and the cause of axial misalignment between optical components of an optical device is that the contact surface of the optical components is rough. It was found that the amount of solidification shrinkage when spot welding the outer periphery of the contact surface differs depending on the location, and further research has been conducted to complete the present invention. That is, the present invention is
Abutting each predetermined surface of the optical component that constitutes the optical device,
In the method for assembling an optical device in which the outer periphery of the contact surface is spot-welded, the contact surface of the optical component has a roughness of 6.3S (JIS
B 0601) This is characterized in that spot finishing is performed after finishing the following smooth surface.

In the present invention, the contact surface of the optical component is 6.3S.
In order to finish the surface with the following roughness, for example, polishing is started from # 1200 abrasive paper and then finished with # 4000 or more abrasive paper. As another finishing method, a chemical polishing method, an electrolytic polishing method, or the like, or a method of cutting the contact surface with a cutting blade having a diamond abrasive grain size of 4 μm or less is used. After finishing, the contact surface is degreased and washed as necessary. In the following examples, those finished by the polishing method will be described in detail. In the present invention, for the measurement of the surface roughness, an arbitrary roughness meter such as a stylus type or a light wave interference type is used. The method of spot welding the outer circumference of the abutting surface of the abutted optical component is not particularly limited, but a high output Y
It is preferable to use an AG laser because welding can be performed accurately in a short time.

[0006]

According to the method of the present invention, in the method for assembling an optical device in which predetermined surfaces of optical components constituting the optical device are brought into contact with each other, and the outer periphery of the contact surface is spot-welded, the contact surfaces of the optical components are roughened. After finishing processing to a smooth surface with a degree of 6.3S (JIS B 0601) or less, spot welding is performed, so the solidification shrinkage of the welded part is made uniform over the entire abutting surface, and the optical axes between the optical parts are accurately aligned. It

[0007]

EXAMPLES The present invention will be described in detail below with reference to examples. The optical device shown in FIGS. 1 to 3 was assembled by the method of the present invention. Example 1 The optical device shown in FIG. 1 is a light emitting element module for coupling the light from the light emitting element 1 to the optical fiber 3 via the lens 2. Assembling the light emitting device module,
After abutting surfaces of the respective optical parts, that is, the light emitting element stem 4, the lens holder 5, and the optical fiber ferrule guide 6 are polished with polishing paper to a roughness of 6.3 S (JIS B 0601) or less, the surfaces are smoothed. The respective optical parts were arranged in contact with each other, and then the outer periphery of each contact surface was spot-welded with a YAG laser.

Example 2 The optical device shown in FIG.
The light receiving element module is configured such that the light from the front spherical portion 7 is received by the light receiving element 8. In assembling the light-receiving element module, the light-receiving element carrier 9 is brazed onto the base 10, and then the abutting surfaces of the optical fiber ferrule guide 6 and the base 10 are polished to a roughness of 6.3S (JIS B 06).
01) After polishing the surface as follows, the optical fiber ferrule guide 6 was placed in contact with a predetermined position on the base 10, and then the outer circumference of each contact surface was spot welded with a YAG laser. .

Example 3 The optical device shown in FIG. 3 has an optical waveguide between the optical fibers 3.
11 are arranged to split or combine light between the optical fibers 3.
It is an optical waveguide type optical coupler. This optical coupler is assembled by the optical fiber ferrule guide 6 and the optical waveguide base 12
After polishing the contact surface of the product with polishing paper to a roughness of 6.3S (JIS B 0601) or less, place each optical component in the specified position and place the contact surface on the outer periphery of the YAG laser. Spot welding was performed.

A light emitting device module (Example 1) was selected from the above examples, and the light coupling efficiency ratio was measured. The coupling efficiency ratio was obtained by measuring the light amount A transmitted to the optical fiber in a state where the optical axes were aligned and abuttingly arranged, and dividing the transmitted light amount B after spot welding by the transmitted light amount A. .
For comparison, the coupling efficiency ratio was determined by the same method for the light emitting element module assembled by finishing the contact surface roughness of the optical component to 25S (JIS B 0601). The results are shown in Fig. 4. As is clear from FIG. 4, in the product of the present invention, those having a coupling efficiency ratio of 1, that is, those having no deviation in the optical axis even after spot welding accounted for 87% of the whole. On the other hand, in the comparative example product, the optical axis was distorted in the latter half or more of the spot welding. Although the optical coupling property of the light emitting element module has been described above, it has been confirmed that good optical coupling property can be obtained also in the optical devices of Examples 2 and 3.

[0011]

As described above, according to the present invention, optical components can be spot-welded without deviating the optical axis, and the optical coupling property of the obtained optical device is good.
It has a remarkable industrial effect.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an example of a mode of a light emitting device module assembled by the method of the present invention.

FIG. 2 is a vertical cross-sectional view showing a mode example of a light receiving element module assembled by the method of the present invention.

FIG. 3 is a vertical sectional view showing an example of an embodiment of an optical coupler assembled by the method of the present invention.

FIG. 4 is a frequency distribution diagram showing a light coupling efficiency ratio of a light emitting device module assembled by the method of the present invention.

[Explanation of symbols]

 1 Light-Emitting Element 2 Lens 3 Optical Fiber 4 Light-Emitting Element Stem 5 Lens Holder 6 Optical Fiber Ferrule Guide 7 Tip Sphere 8 Light-Receiving Element 9 Light-Receiving Element Carrier 10 Base 11 Optical Waveguide 12 Optical Waveguide Base

Claims (1)

[Claims] 1. A method for assembling an optical device in which predetermined surfaces of optical components constituting an optical device are brought into contact with each other, and the outer periphery of the contact surface is spot-welded, and the contact surface of the optical components has a roughness of 6.3. S (JIS B 0601) A method for assembling an optical device, which comprises spot-welding after finishing to a smooth surface of the following.