JPH0345914A - Optical coupler - Google Patents

Abstract

PURPOSE:To suppress the axial shift of an optical fiber at the time of fixing laser fusion by making the center of a hole where an optical fiber is inserted eccentric with the center of a ferrule, and fixing the optical fiber on the basis of fusion of a shaft and a hole. CONSTITUTION:Two mutually parallel shafts 13 and 14 are extended and fixed on a base 10 at right angles to the optical axes of a semiconductor laser 11 and a lens 12, holes 16 and 17 where the shafts 13 and 14 are inserted are bored in the support 15, and a hole 19 where a ferrule 18 is inserted is bored above the holes 16 and 17. Then an optical fiber 20 whose core center is eccentric with the ferrule center is put in the ferrule 18. Therefore, the shafts 13 and 14, and ferrule 18 are fitted in the holes 16 and 17, and 19 formed in the support 15 and then weld zone stress at the time of laser welding can be absorbed with their fitting force. Consequently, the generation of the optical axis deviation of the optical fiber 20 at the time of fusing and fixing can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical coupler used inside a semiconductor laser module or the like used in optical communication, optical information processing, etc.

[Conventional technology]

Conventionally, as shown in FIGS. 3 and 4, this type of optical coupler includes a base 2 to which a semiconductor laser is fixed, a support 3 that is in plane contact with the base 2, and a support that is inserted and held in the support 3. The ferrule 4 and the support 3 and the support 3 and the base 2 are each fixed by laser welding. Note that a lens 6 is arranged inside the base 2 so as to face the optical fiber 5.

[Problem to be solved by the invention]

However, in the conventional optical coupler described above, since the base 2 and the support 3 are in contact with each other on a plane, when fixing this part, the materials of the base 2 and the support 3 melted by the laser solidify. Stress is generated, and the relative positions of the base 2 and the support 3 tend to shift in the direction of the contact surface. That is, the relative positions of the semiconductor laser 1 and the ferrule 4, which are fixed to the base 2 and the support 3, respectively, are likely to shift when the base 2 and the support 3 are fixed, and therefore the light to the optical fiber 5 fixed to the ferrule 4 is easily shifted. It has the disadvantage that the coupling efficiency tends to decrease.

The object of the present invention has been made in view of the above-mentioned drawbacks.
It is an object of the present invention to provide an optical coupler that can suppress axis deviation of an optical fiber as much as possible when fixed by laser welding.

[Means to solve the problem]

In order to achieve the above-mentioned object, an optical coupler according to the present invention includes a base on which a light emitting element is fixed, an optical fiber arranged at a predetermined distance from the light emitting element, and an optical coupler into which the optical fiber is inserted. In an optical coupler that includes a ferrule for holding and a support for holding the ferrule against a base, the base is provided with a shaft in a direction perpendicular to the optical axis of the light emitting element, and the support includes a shaft. A hole is provided into which the shaft is inserted, and the ferrule is provided such that the center of the hole into which the optical fiber is inserted is eccentric with respect to the ferrule.

[Effect]

In this way, the coupler of the present invention has a structure in which the optical fiber is fixed based on the connection between the shaft provided in the base and the hole provided in the support. It can absorb the stress that occurs when the molten part solidifies. Therefore, it is possible to suppress as much as possible the axis deviation of the optical fiber that occurs when fixing by laser welding.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing an embodiment of an optical coupler according to the present invention, and FIG. 2 is a plan view of the same optical coupler. base 10
A semiconductor laser 11, which is a light emitting element, is fixed to , and a lens 12 for condensing the light emitted from the semiconductor laser 11 is arranged and fixed at a position spaced apart from the semiconductor laser 11 by a predetermined pressure n. . Furthermore, two parallel shirts 13 and 14 are extended and fixed to the base 10 in a direction perpendicular to the optical axes of the semiconductor laser 11 and the lens 12. On the other hand, support 15 has shirt) 1
A hole 16.17 for inserting the ferrule 18 is bored at the upper position of the hole 16.17. An optical fiber 20 is built into the ferrule 18 with the core center being eccentric with respect to the center of the ferrule.

In the above configuration, the optical axis of the semiconductor laser 11 and the lens 12 and the optical axis of the optical fiber 20 are determined by the movement of the support 15 guided by the shaft 13.14 provided on the base 10 and the movement of the ferrule 18. It can be matched by rotation.

On the other hand, the condensing point of the lens 12 and the end surface of the optical fiber 20 can be brought into alignment by inserting and removing the ferrule 18 along the hole 19 provided in the support 15. After adjusting each part in this way, shirt) 13.
14 and the ferrule 18 and the support 15 are fixed by laser welding. At this time, shaft 13.14i6
If the holes 6, 17, and 19 provided in the support 15 are used as fitting holes for the ferrule 18 and the ferrule 18, the stress in the welded part during laser welding can be absorbed by this fitting force. The occurrence of optical axis deviation of the optical fiber 20 can be suppressed.

〔Effect of the invention〕

As explained above, according to the optical coupler according to the present invention,
A shaft is provided in the base in a direction perpendicular to the optical axis of the light emitting element, and a hole is provided in the support into which this shaft is inserted, and the ferrule is arranged so that the center of the hole into which the optical fiber is inserted is eccentric to the center of the ferrule. The structure is such that the optical fiber is fixed based on the connection between the shaft and the hole, so the stress generated when the molten part solidifies during laser welding is ensured by the fitting force between the shaft and the hole. can now be absorbed into. Therefore, the optical fiber axis is less likely to be misaligned during laser welding, and this has the excellent effect of making it possible to fix the base and the support with high precision.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the optical coupler according to the present invention, FIG. 2 is a bottom view of the same optical coupler, and FIG. 3 is a plan view showing an example of a conventional optical coupler. FIG. 4 is a longitudinal sectional view showing an example of a conventional optical coupler. 10...Base, 11...Semiconductor laser, 12...Lens, 13.14...
Shaft, 15...Support, 16.17...
...hole, 18...ferrule, 19...
...hole, 20...optical fiber.

Claims (1)

[Claims] A base to which a light emitting element is fixed, an optical fiber arranged at a predetermined distance from the light emitting element, a ferrule for inserting and holding the optical fiber, and a support for holding the ferrule with respect to the base. In the optical coupler, the base is provided with a shaft in a direction perpendicular to the optical axis of the light emitting element, and the support is provided with a hole into which the shaft is inserted, and the support is provided with a hole into which the shaft is inserted. An optical coupler characterized in that the ferrule is provided such that the center of the hole into which the optical fiber is inserted is eccentric to the ferrule.