JPS61241715A - Manufacture of semiconductor laser-optical fiber coupling device with optical isolator - Google Patents

Abstract

PURPOSE:To reduce the deterioration in the coupling efficiency and output fluctuation due to temperature variation of the titled device in the course of manufacture, by positioning optical fibers under a condition where the fitting surfaces of the 1st and 2nd fixing jigs are always pulled from each other with fixed negative pressure by the force of magnets and only slight unevenness which is equivalent to machining accuracy exists and fixing the optical fibers to each other at the time of maximum coupling efficiency. CONSTITUTION:When a ferrule holder 12 which becomes the 2nd fixing jig is formed of a metallic material which can be attracted by a magnet 8, the legs of the ferrule holder 12 are always closely contacted with the magnet 8 with negative pressure and, even when moved in x-z directions, the ferrule holder 12 never tilts. Moreover, since a magnet holder 9 which constitutes part of the 1st fixing jig covers the upper surface of the magnet 8 leaving part for passing light uncovered and magnetic force can be transmitted, the legs of the ferrule holding 12 are closely contacted with the magnet holder 9 and metal fixing of resistance welding, etc., can be made.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing a semiconductor laser/optical fiber coupling device with an optical isolator used as a light source for optical signal transmission in optical communications, etc. FIG. 3 shows a vertical cross-sectional view of an example of a semiconductor laser/optical fiber coupling device with an optical isolator based on a concentric cylindrical shape. Emitted light from a semiconductor laser 2 fixed on a package stem 1 is focused onto an optical fiber 6 by a lens 5 fixed to a lens holder 4. The magneto-optical crystal 7 is capable of rotating linearly polarized light by 46 degrees using a magnet 8 and is fixed to the lens holder 4 using a magnet holder 9. Further, the polarizer 1o fixes the light emitted from the semiconductor laser 2 so that the direction of polarization is aligned with that of the polarized light whose plane of polarization is rotated by 45 degrees in the magneto-optic crystal 7.

The conventional manufacturing procedure for a coupling device is to complete the above-mentioned system as one set, guide the ferrule 11 to which the optical fiber 6 is fixed through the ferrule holder 12 with a clearance of about 2 μm, and align the optical axis. Fine adjustments were made with a manipulator in parallel directions (two directions) and in a direction perpendicular to the optical axis (x-y direction), and the bond was more firmly attached to the resin adhesive at the maximum coupling efficiency.

Problems to be Solved by the Invention In such a conventional manufacturing method, when the ferrule 11 is held by a manipulator and moved in the X, y, and z directions, the ferrule holder 12 gets caught when it slides on the magnet 8,
Due to play in the manipulator, inclination of the manipulator, etc., the ferrule holder may tilt even though it is connected as shown in Figure 2. If the ferrule holder is fixed with resin adhesive in this state, the thickness of the adhesive The coupling efficiency deteriorated during curing due to differences in the temperature, and the output fluctuated due to temperature fluctuations, resulting in a lack of reliability. In addition, in FIG. 3, the ferrule holder 12 is fixed to the magnet 8, but by making the shape of the magnet holder 9 into a cab-like shape with only a hole through which light passes, the ferrule holder 12 can be resistance welded to the magnet holder 9. However, in the case shown in Fig. 2, resistance welding requires pressure to be applied, resulting in deterioration of coupling efficiency.

The present invention has been made in view of the above points, and provides a method for manufacturing a semiconductor laser optical fiber coupling device with an optical isolator that is easy to manufacture, has little deterioration in coupling efficiency during manufacturing, and has little output fluctuation due to temperature changes. It is intended to.

Means for solving the problems and technical means of the present invention for solving the above problems are as follows:
A semiconductor laser, a lens, a magneto-optic crystal, a magnet, and a polarizer are each fixed by a first fixing jig, and an optical fiber is guided in directions parallel and perpendicular to the optical axis of the first fixing jig. A second fixing jig made of a metal material whose position is adjustable and which is attracted to a magnet is used to hold the first fixing jig.
It is fixed to the fixing jig at the position where the coupling efficiency is maximum.

According to the above-described manufacturing method of the present invention, the mating surfaces of the first fixture and the second fixture are always drawn together with a constant negative pressure by the magnet, and the unevenness is as high as the machining accuracy. Embodiment 1: By positioning the optical fiber in a state where the optical fiber is only available, and fixing it at the point where the coupling efficiency is maximum, there is less deterioration of the coupling efficiency during manufacturing, there is little output fluctuation due to temperature fluctuation, and the manufacturing method is easy.0 Example 1 The figure is a longitudinal cross-sectional view of an embodiment for explaining the manufacturing method of the present invention. Since the configuration of the coupling device itself has already been explained with reference to FIG. 3, it will be omitted here. The ferrule holder 12, which serves as the second fixture, is made of a metal material that is attracted by the magnet 8, so that the ferrule holder 120 legs are always in close contact with the magnet 8 under negative pressure, even when moved in the +7+z direction. There is nothing wrong with the ferrule holder 12 as shown in FIG. Since the upper surface is hidden and the magnetic force is transmitted, the legs of the ferrule holder 12c and the magnet holder 9 are in close contact and C metal can be fixed by resistance welding etc. Magnet 8
It is difficult to fix the upper surface of the ferrule holder 12 to the legs of the ferrule holder 12 using metal.

The magneto-optic crystal 7 for the 1.3 μm band optical isolator is Y
In the case of IG, the thickness of the magnet 8 is 21 rs and the e-field strength at the center of the magnet 8 is about 8000 s, and the metal material of the ferrule holder 12 is stainless steel 430 or the like.

Effects of the Invention As described above, according to the manufacturing method of the present invention, the manufacturing method is easy, and the coupling efficiency is reduced during manufacturing, and the output fluctuation due to temperature fluctuation is small. A method for manufacturing the device can be realized.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view of a ferrule holder portion for explaining an embodiment of the method for manufacturing a semiconductor laser/optical fiber coupling device with an optical inulator according to the present invention, and Fig. 2 is a longitudinal/sectional view for explaining a conventional manufacturing method.・A vertical cross-sectional view of the ferrule holder portion, and FIG. 3 is a vertical cross-sectional view of a conventional semiconductor laser/optical fiber/coupling device with an optical inulator. 2... Semiconductor laser, 5... Lens,
6...Light, fiber, 7...Magneto-optical crystal, 8...Magnet, 10ε...
・Polarizer, 11... Ferrule, 12...
...Ferrule holder.

Claims (1)

[Claims] A semiconductor laser, a lens for condensing light emitted from the semiconductor laser onto an optical fiber, a magneto-optic crystal, a magnet, and a polarizer are each fixed by a first fixing jig, and the optical fiber is guided by the first fixing jig. A second fixing jig made of a metal material that can be adjusted in parallel and perpendicular directions to the optical axis of the jig and is attracted to the magnet is used, and the second fixing jig is attached to the first fixing jig. A method for manufacturing a semiconductor laser/optical fiber coupling device with an optical isolator, characterized in that the device is fixed to a fixing jig at a position where optical coupling efficiency is maximized.