JPS6213286A - Laser beam welding and fixing method - Google Patents

Abstract

PURPOSE:To minimize the positional deviation between a lens and fiber in positioning and fixing of the lens and fiber by providing a flange part which is projected outward to a welding ring for fixing the fiber and fixing said ring to a lens holder by irradiating a beam in the direction perpendicular to the holder. CONSTITUTION:The lens holder 5 and ferrule holder 7 are first fixed respectively to the welding rings 8, 9 by the irradiation (a), (b) of the beam is positioning and fixing of the lens 3 and the fiber 4 with respect to a laser 1. A laser holder 2 and the welding ring 8 of the lens 3 are then fixed by the irradiation (b) of the beam. The beam is further irradiated (d) in the direction perpendicular to the projecting flange part of the ring 9 to fix the lens holder 5 and the ring 9 of the fiber 4 thereby fixing the lens 3 and the fiber 4 in the correct relative positions.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a laser welding fixing method used for fixing the position of laser module components for optical communication.

(Prior Art) FIG. 2 is a block diagram of a conventional optical communication laser module. In the figure, 1 is a laser, 2 is a laser holder, and 3 is a laser.
5 is a lens for coupling laser light into a fiber 4, 5 is a lens holder, 6 is a ferrule into which the fiber is inserted, and 7 is a ferrule holder. 8 is lens holder 5
This is a welding ring for fixing the position of the laser holder 2, and the YAG
Weld and fix it by irradiating it with a high-power laser beam such as a laser. Reference numeral 9 denotes a welding ring for fixing the positions of the lens holder 5 and the ferrule holder 7, and the welding ring 9 is welded and fixed by irradiating a laser beam from the direction of the arrow attached to the welding ring 9.

Since the necessary precision for fixing the position between the fiber and the lens is usually less than the precision required for fixing the position between the lens and the laser, the lens and the laser are first fixed by welding (arrows a, b). Then, the position of the fiber is corrected by adjusting the position of the fiber, and the fiber and the lens are welded and fixed by welding in the order of c and d. In the case of a relatively large multimode fiber with a core diameter of several tens of μm, the allowable value for horizontal deviation in the final weld d is as large as about IOμm, so current laser welding technology can reduce the deterioration in coupling efficiency to a small value. It can be suppressed. However, in the case of a single mode fiber with a core diameter of 10 μm or less, the final weld d
Since the allowable value for horizontal deviation is as small as about 2 μm, it is necessary to use a welding method that causes as little deviation as possible.

In the welding ring having the shape shown in Fig. 2, the irradiation of d, which fixes the positions of the welding ring 9 and the lens holder 5, is from an oblique direction, so an average deviation of about 10 μm occurs in experiments.
The coupling efficiency of modules during welding is greatly degraded.

(Problems to be Solved by the Invention) In the conventional laser welding fixing method described above, since the final welding is laser beam irradiation from an oblique direction, there is a large shift that occurs during welding, and the laser beam for single mode fiber is Fixing the module by welding has the disadvantage that the coupling efficiency deteriorates significantly.

An object of the present invention is to provide a laser welding fixing method that eliminates the conventional drawbacks and can suppress a small deterioration in coupling efficiency even when welding fixing a single mode fiber laser module.

(Means for Solving the Problems) The laser welding fixing method of the present invention fixes the positions of the respective holders of fibers, lenses, and lasers, which are components of a semi-dedicated laser module for optical communication, and finally fixes them. A welding ring is used to project the welding part of the holder to the outside of the holder, and a laser is irradiated from a direction perpendicular to the contact surface between the welding part and the mating part.

Further, in the laser welding fixing method of the present invention, the surface of the welding ring used to fix the positions of two parts by laser welding is shaped so that it contacts the surface of one or both parts over a wide area. It is something.

(Function) According to the present invention, with the above-described configuration, the last welding with the smallest allowable value for deviation can be performed by beam irradiation from a direction perpendicular to the deviation direction, so that the deviation value can be reduced to 2 μm on average.
Therefore, deterioration in coupling efficiency can be suppressed to a small level not only in multimode fiber laser modules but also in welding fixation of single mode fiber laser modules.

(Example) An embodiment of the present invention will be described based on FIG.

FIG. 1 is a configuration diagram of a laser module of the present invention. In this figure, the same parts as those in the conventional example shown in FIG. 2 are given the same numbers, and the explanation thereof will be omitted. In FIG. 1, the positions of the lens and laser are first fixed by beam irradiation as indicated by arrows a and b. Next, the position of the fiber 4 is adjusted so that the coupling is maximized again, and welding and fixing is performed by beam irradiation in the order of arrows c and d. The shape of the welding ring 9 is different from that of the conventional example shown in FIG. 2, and the welded portion protrudes outward from the lens holder 5, so that the last beam irradiation shown by arrow d is performed from a direction perpendicular to the direction of deviation. be able to.

For this reason, the amount of deviation due to this welding method is experimentally estimated to be 2 on average.
It is small, about μm. Therefore, in this embodiment, deterioration in coupling efficiency can be suppressed to a small level not only in the laser module for multimode fiber but also in the welding fixation of the laser module for single mode fiber.

Furthermore, if the contact area between the welded part and other parts is made as large as possible, misalignment during welding will be reduced and work will be stabilized.

(Effect of the invention) The present invention enables the final welding of laser module parts to be fixed.
Since this can be performed by beam irradiation from a direction perpendicular to the direction of deviation, it has the advantage that the amount of deviation can be suppressed to a small value of about 2 μm. Therefore, even when fixing a single mode fiber laser module by welding, there is an effect that deterioration in coupling efficiency during welding can be suppressed to a small value.

Furthermore, if the contact area between the welded part and other parts is increased, the displacement during welding work will be reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a laser module according to an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional laser module. 1... Laser, 2... Laser holder,
3...Lens, 4...Fiber, 5.
... Lens holder, 6 ... Ferrule, 7.
...Ferrule holder, 8,9...Welding ring. Patent applicant Matsushita Electric Industrial Co., Ltd. Figure 1

Claims (2)

[Claims] (1) The welding part of the welding ring used to fix the position of two parts by laser welding is made to protrude outward from the welding ring, and the welding part and the other part come into contact with each other. A method for laser welding and fixing a laser module, characterized by welding from a direction perpendicular to a surface. (2) The laser welding fixing method according to claim (1), wherein the welded portion has a large contact area with other parts.