JPH03216606A - Method for fixing optical parts by laser welding - Google Patents

Abstract

PURPOSE:To lessen the misregistration which arises at the time of welding and fixing by irradiating the thin notched parts provided in the outer peripheral part of a fiber holder with a laser from the direction perpendicular to a joint surface to tack weld this part, then subjecting the entire circumference of the outer peripheral part of the fiber holder to regular welding. CONSTITUTION:The fiber holder 8 inserted with an optical fiber 6 fixed to a ferrule 7 is pressed to a container 5 adjusted and fixed with optical parts, such as optical semiconductor element (semiconductor laser) 1, coupling optical system 3, lens holder 4 and stem 2 for installing these parts. The position of the fiber holder 8 is so adjusted as to have high optical coupling efficiency. The thin notched parts 9a to 9d provided in the outer peripheral part of the fiber holder 8 are thereafter irradiated with the laser and are thereby tack welded. The entire circumference in the outer peripheral part of the fiber holder 8 is then fixed by regular welding. The misregistration arising at the time of fixing the fiber holder by the laser welding is lessened in this way and the degradation in the optical coupling efficiency between the optical semiconductor element (semiconductor laser) and the optical fiber is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a semiconductor laser module for optical communication. [Prior Art] When manufacturing a conventional semiconductor laser module for optical communication, the optical fiber is fixed at a position where the optical coupling efficiency between the optical semiconductor element and the optical fiber is high. A method to prevent misalignment has been proposed.
FIG. 3 is a block diagram of a semiconductor laser module for optical communication described in Japanese Patent Application Laid-open No. 13286/1986. An optical fiber 6 for extracting optical output is fixed to a fiber holder 8 via a ferrule 7 and a ferrule holder 9. The fiber holder 8 is fixed to the lens holder 4 by welding, and by welding with laser irradiation from the direction d in the figure (perpendicular to the joint surface), the amount of positional deviation after welding is reduced to 2μ on average.
It can be made as small as m. FIG. 4 is a drawing showing the technique disclosed in Japanese Patent Application Laid-Open No. 62-217212. Optical fiber 6 is fixed to fiber holder 8 via ferrule 7. The fiber holder 8 is welded and fixed to the lens holder 4, and by laser welding the inner parts 10a, b, and c of the notches shown in the figure, no displacement occurs due to solidification shrinkage of the molten metal.

[Problem to be solved by the invention]

In the above conventional technology, the thickness of the laser welded portion of the fiber holder 8 is not considered in FIG. 3, and if the thickness is increased to ensure the strength of the joint, the laser welding device used It was necessary to increase the power capacity of the laser to increase the laser output, and at the same time there was the problem of thermal effects due to temperature rise during welding. In addition, in FIG. 4, the fiber holder 8
Since it has a notch, it is difficult to weld the entire circumference of the outer circumference, and it is impossible to seal it airtight by laser welding.

An object of the present invention is to reduce the positional deviation that occurs when a fiber holder that fixes an optical fiber is welded and fixed during the manufacture of a semiconductor laser module for optical communication. [Means for solving the problem] In order to achieve the above objective, multiple thin-walled notches are provided on the outer periphery of the fiber holder, and the thin-walled notches are irradiated with a laser from a direction perpendicular to the joint surface to perform tack welding. Then, the entire outer circumference of the fiber holder was fully welded. Furthermore, in order to reduce positional deviation during welding, all thin-walled notches are tack welded at the same time, or
A pair of pieces facing each other are tack-welded one after the other at the same time.

[Effect]

The thin-walled notch provided in the fiber holder allows laser irradiation from a direction perpendicular to the joint surface where positional displacement is unlikely to occur during tack welding, and also makes it easy to laser weld the entire circumference, making it airtight. A joint with excellent properties can be obtained. Additionally, the wall thickness of the notch can be set to a thickness commensurate with the power capacity of the laser welding equipment, and by making only the notch thinner, the strength of the entire joint will not be reduced. [Example] An example of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a sectional view showing a semiconductor laser module for optical communication, and the main optical components include an optical semiconductor element (semiconductor laser) 1, a coupling optical system 3, a lens holder 4, a stem 2 in which they are installed, and a container. 5, an optical fiber 6, a ferrule 7, and a fiber holder (holding part) 8.

FIG. 2 is a plan view of the fiber holder 9, showing the thin cutout 9.
Indicates a, bt c, d. Next, a method of welding and fixing the fiber holder of this embodiment will be explained. First, the fiber holder 8 into which the optical fiber 6 fixed to the ferrule 7 is inserted is pressed against the container 5 in which the optical components have been adjusted and fixed in a predetermined position, and the fiber holder 8 is aligned and adjusted so that the optical coupling efficiency is high. do.
Thereafter, the thin cutouts 9a, b, c, and d provided on the outer periphery of the fiber holder 8 are irradiated with a laser from the direction of the arrow in the figure to perform temporary welding. At that time, 9a, b, c, d at the same time,
Alternatively, simultaneously 9a and 9c facing each other, then 9b and 9
It is also possible to tack weld d at the same time.

Thereafter, the entire outer circumference of the fiber holder 8 is fixed by laser welding. The same laser welding equipment used for tack welding may be used for this welding, but it can also be performed on a separate production line. According to this embodiment, the positional shift that occurs when fixing the fiber holder by laser welding is reduced, and a decrease in the optical coupling efficiency between the optical semiconductor element (semiconductor laser) and the optical fiber can be prevented. [Effects of the Invention] According to the present invention, in manufacturing a semiconductor laser module for optical communication, the fiber holder, which is a holding part for an optical fiber, can be fixed by laser welding with little misalignment, so the optical coupling efficiency is reduced. do not.

[Brief Description of the Drawings] Figure 1 is a sectional view of a semiconductor laser module for optical communication according to an embodiment of the present invention, Figure 2 is a plan view of the fiber holder in Figure 1, and Figure 3 is a conventional FIG. 4 is a cross-sectional view showing a conventional method of fixing an optical fiber in a fiber holder, and FIG.
) is shown. DESCRIPTION OF SYMBOLS 1... Optical semiconductor element (semiconductor laser), 2... Stem, 3... Coupling optical system (lens), 4... Lens holder, 5... Container, 6... Optical fiber, 7 ... Ferrule, 8... Fiber holder, 9a=b, c, d
... Thin wall notch I Figure 2 Field

Claims (1)

[Scope of Claims] 1. In an optical element module comprising an optical semiconductor element, a coupling optical system, and an optical fiber for extracting optical output, the optical fiber is held in a container part in which the optical semiconductor element and the coupling optical system are installed. A plurality of thin cutouts provided on the outer periphery of the holding part are provided with a holding part for fixing the holding part, and the holding part is aligned and adjusted so as to increase the optical coupling efficiency between the optical semiconductor element and the optical fiber. The contact surface with the container part is irradiated vertically with a laser to perform tack welding, and then the entire outer circumference of the holding part is welded by laser welding to fix it and hermetically seal it. Laser welding method for fixing optical components.