JPH0746891Y2 - Optical axis fixing structure for optical components - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an optical axis fixing structure in an optical component for optical communication.

An optical multiplexer / demultiplexer used for optical communication is composed of, for example, an optical fiber, an optical fiber coupling lens and a filter, and has a function of efficiently multiplexing or demultiplexing input light and outputting it to an optical fiber cable. Is equipped with.

Optical components for optical communication are required to have stable performance for a long time against vibration, shock, temperature change and humidity change, and the fixing structure of the optical component to the base plate is an important factor that determines its reliability. is there.

In a conventional optical multiplexer / demultiplexer, optical components such as an optical fiber collimator and a filter of the optical multiplexer / demultiplexer are fixed to a base plate with an adhesive while adjusting their positions.

[Problems to be solved by the invention]

In the conventional optical multiplexer / demultiplexer described above, since the optical components are attached to the base plate by using an adhesive, deterioration of the adhesive and deterioration of the adhesive due to shock, vibration, etc. In addition to the lack of stability, there is a problem that a great number of man-hours are required to prepare the adhesive. Furthermore, since the variation in the formulation of the adhesive affects the adhesive strength of the adhesive, sufficient care must be taken in its management, and in order to prevent the adhesive from adhering to the optical path of the optical component, There was a problem that a lot of man-hours were required for the work.

[Means for solving problems]

According to the present invention, when fixing an optical component such as a holder supporting an optical fiber collimator or an optical functional element to a predetermined position of the base plate, a plurality of layers having appropriate thicknesses are left at required positions on the back surface of the base plate. The counterbore holes are provided individually, and the optical fiber collimator or the holder is heated and melted on the surface of the base corresponding to the predetermined counterbore holes by the laser device that irradiates the laser beam into the counterbore holes,
An object of the present invention is to provide an optical multiplexer / demultiplexer in which the number of assembling steps is small and the reliability of the fixing portion is improved by welding the above optical component to the base plate.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 to 3, a base plate 1 is for fixing an optical component to be described later, and is made of a solid material to prevent optical axis coupling deviation of the optical component due to mechanical stress from the outside such as vibration and impact. It is made of a flat metal plate.

The plurality of optical fiber collimators 2, 3 and 4 are formed by mounting an optical axis coupling lens and an optical fiber (not shown) in a case 5 made of a metal pipe.

The filter 6 is formed by stacking dielectric materials having different refractive indexes on a glass substrate in multiple layers. The standing plate of the metal-made L-shaped holder 7 is provided with a hole for the optical path, and the filter 6 is provided on the surface of the standing plate at the position of this hole.
Is stuck.

An optical multiplexer / demultiplexer is configured by arranging and fixing the optical components including the above optical fiber collimators 2, 3, 4 and the film 6 as shown in FIG.

On the back surface side of the base plate 1, the optical components 2, 3,
4 and a position opposite to the position where the holder 7 is to be attached, a plurality of counterbored holes 8 are formed so as to leave an appropriate thickness.
Has been drilled. With each optical component 2, 3, 4, and 7 positioned as shown in FIG. 1, by irradiating each counter bore with YAG laser light, the thin portion 8a of the counter bore 8 is melted. Then, each optical component 2, 3, 4 and the holder 7 are welded to the base plate 1.

Temporarily, on the front surface side of the base plate 1, the optical components 2, 3, 4,
When trying to weld the holder 7 and the optical component 2,
It is difficult to irradiate a laser beam on the boundary between the holder 3 and the holder 7 and the base plate 1, and the postures of the optical components 2, 3 and 4 and the holder 7 change due to the stress generated during cooling of the welded portion. , The adjusted optical axis may shift.

However, in the above embodiment, the welding is performed by heating from the countersunk hole 8 on the back surface side of the base plate 1,
The optical axis adjusted in advance does not deviate, and the welding operation can be performed within a short time.

A half mirror having a reflectance of 50% was used as the holder 7, and an assembly of a three-terminal optical directional coupler was performed. As a result, the work of fixing the optical axis is shortened to 1/5 of that of the conventional method, and the loss variation is ± 0.3 dB (measurement error) or less for 500 temperature cycles of -10 to 60 ° C, which is extremely stable. The degree has been confirmed.

Although the optical multiplexer / demultiplexer has been described as an example of the optical component, various optical components using a prism dimming element, a Faraday element, or the like as the optical function element can be configured. Therefore,
The present invention can contribute to high reliability and assembly of various optical components for optical communication.

[Effect of device]

As described above, according to the optical axis fixing structure of the present invention, a counterbore hole having an appropriate thickness is formed at a predetermined position on the back surface side of the base plate to which the optical component is to be fixed, and the base plate is inserted from within the counterbore hole. By heating and melting a part of the above with a laser device and fixing the optical parts, the number of assembly steps of optical parts can be reduced,
In addition, it is possible to improve the reliability of the fixed part of the optical component.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of an optical multiplexer / demultiplexer to which an embodiment of the optical axis fixing structure according to the present invention is applied, FIG. 2 is a front view of the optical multiplexer / demultiplexer, and FIG. 3 is an optical multiplexer. It is a rear view of a duplexer. 1 ... Base plate, 2, 3, 4 ... Optical fiber collimator, 5 ... Case, 6 ... Filter, 7 ... Holder, 8
…… Counterbore, 8a …… Thin part.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Toshio Aikawa 3-20-4 Nishi-Shimbashi, Minato-ku, Tokyo Inside NEC Engineering Co., Ltd. (56) References JP-A-58-48489 (JP, A) Actual Kai 57-110519 (JP, U) Actual public 54-39457 (JP, Y1)

Claims (1)

[Scope of utility model registration request] 1. At least one optical fiber collimator including an optical fiber and a lens whose focal point is located at the end thereof, or an optical component having an optical functional element, wherein at least one of the optical fiber collimator or the optical functional element is provided. Is attached to a metal holder, and at least one of the metal holder of the optical fiber collimator or the metal holder accommodating the optical function element is formed with a countersunk hole leaving a thin portion having an appropriate thickness. Of the flat plate-shaped base plate, which is opposite to the surface on which the countersink hole is formed, is arranged at the position where the countersink hole is formed, and the position where the countersink hole is provided is irradiated with laser light. The optical axis fixing structure in the optical component, wherein the thin portion and the metal holder are fixed by heating and melting.