JPH0843690A - Semiconductor optical module - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a semiconductor optical module capable of reducing the number of module constituent parts, suppressing the variation in the distance in the optical axis direction, and reducing the variation in the optical output or the light receiving sensitivity. [Structure] A laser beam emitted from a semiconductor laser 1 is incident on an optical fiber of a ferrule 6 which is arranged and fixed in a light transmitting relationship with the semiconductor laser 1, and is further subjected to a predetermined polishing treatment of the ferrule 6. A ferrule 7 that has been subjected to a predetermined polishing process as in the case of one end physically propagates through a signal transmission optical fiber 9 that is coupled so as to have an optical transmission relationship by physically contacting at a connection portion C. The ferrule 6 and the ferrule holder 5 are sealed and fixed by solder at the connecting portion B, and the ferrule holder 5 and the stem 3 are sealed and fixed by solder or welding at the connecting portion A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various optical communication devices, that is, trunk line communication using optical fibers as transmission lines, factory automation (FA), office automation (OA), on-premises communication network (LAN), CATV system, The present invention relates to a semiconductor optical module used in a wireless analog transmission system or the like, or a subscriber system or the like for providing B-ISDN services aimed at future broadband services to each home.

[0002]

2. Description of the Related Art FIG. 7 shows the structure of a conventional semiconductor optical module in which a light emitting and receiving element and an optical fiber are combined. In FIG. 7, this semiconductor optical module holds a focusing rod lens 23 with a holding member 24. And optical fiber 2
The optical fiber terminal member 22 holding the optical fiber jacket 21, which is the jacket of 0, is put into the holding member 24, and they are fitted together by the screw coupling portion 25 so that there is no gap therebetween. Next, a joining portion 26 between the holding member 24 and the optical fiber terminal member 22.
Spot welding of A and 26B is performed by a high power laser or the like.
Then, the light emitting diode element 19 is adjusted to an optimum position where the emitted light is most efficiently incident on the optical fiber 20. The joining portions 26C and 26D of the light emitting diode element holding member 27 and the holding member 24 are similarly spot-welded to have a structure. A module related to this type of module is disclosed in, for example, Japanese Unexamined Patent Publication No.
There is a 2807 publication.

[0003]

In the above-mentioned prior art, by welding the holding member and the optical fiber terminal member,
It was possible to fix the optical fiber terminal member to the holding member without using an adhesive, and the usable range of the semiconductor optical module was not affected by the curing temperature of the adhesive. However, in the above-mentioned conventional technique, since the optical coupling is performed using the lens, the variation in the optical output due to the variation in the distance between the lens and the optical fiber is apt to occur, and the holding member 24 and the light emitting diode element are held together. Since the member 27 is required, the number of parts is increased, and there is a problem that the reduction of the module price is hindered.

The present invention solves the above problems of the prior art,
An object of the present invention is to provide a semiconductor optical module capable of reducing the number of module constituent parts, suppressing variations in distance in the optical axis direction, and reducing variations in optical output or light receiving sensitivity.

[0005]

In order to achieve the above-mentioned object, the following technical means are adopted.

A single ferrule is inserted between the light emitting / receiving element and the optical fiber for signal transmission as an intermediary for optical coupling, and airtight sealing is performed at the connecting portion between the ferrule and the package.

[0007]

In the present invention, the ferrule alone is inserted between the light emitting / receiving element and the optical fiber for signal transmission as an intermediary for optical coupling, whereby optical coupling is achieved without using a lens, and the cost of the semiconductor optical module is reduced. It is possible.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of claim 1 of the present invention will be described below with reference to FIGS. 1, 2, 3, 4, 5, and 6.

FIG. 1 shows a simplified cross-sectional view of a main part of a semiconductor laser module using a semiconductor laser according to an embodiment of the present invention. In the figure, the laser light emitted from the semiconductor laser 1 is incident on the optical fiber of the ferrule 6 which is arranged and fixed in an optical transmission relationship with the semiconductor laser 1.
Further, the ferrule 7 that has been subjected to a predetermined polishing treatment is also physically connected to the other end of the ferrule 6 that has been subjected to a predetermined polishing treatment so that the ferrule 7 is coupled so as to have a light transmission relationship. The structure is such that it propagates through the signal transmission optical fiber 9.

Next, an example of the assembling method will be described with reference to FIG. (1) The submount 2 having the semiconductor laser 1 attached to a predetermined position of the stem 3 is die-bonded, and then the photodiode 12 is attached to the predetermined position of the stem 3 so as to have an optical transmission relationship with the semiconductor laser 1. The attached submount 11 is die-bonded. (2) The semiconductor laser 1 and the photodiode 12 are wire-bonded to a predetermined position of the lead terminal of the stem 3. (3) Insert the ferrule 6 into the ferrule holder 5 and perform an experiment in advance so that the distance from the end face of the ferrule 6 on the semiconductor laser 1 side to the end face of the ferrule holder on the stem 3 side will maximize the fiber end output of the optical fiber 9. Alternatively, the ferrule 6 and the ferrule holder 5 are sealed and fixed at the connection portion B with solder or the like so that the ferrule 6 and the ferrule holder 5 come to the position where the distance determined by the calculation is realized. (4)
The ferrule holder 5 assembled in (3) is mated with the master optical connector prepared in advance. At this time, the ferrule 6 and the connecting portion C of the ferrule 7 physically contact (Phys
ical contact). Next, the semiconductor laser 1 is caused to emit light, and while monitoring the fiber end output of the optical fiber 9, the positions of the stem 3 and the ferrule holder 5 are adjusted so that the optical output has a maximum positional relationship. (5) After the adjustment is completed, the stem 3 and the ferrule holder 5 are sealed and fixed at the connection portion A by soldering or welding, and the semiconductor laser module is completed.

FIG. 2 shows a semiconductor laser module according to claim 2 according to another embodiment of the present invention. The tip of the ferrule 6 on the light emitting and receiving element side in FIG. 1 is obliquely polished as shown by the ferrule 13 in FIG. 2 to reduce the reflected light.

FIG. 3 shows a semiconductor laser module according to claim 3 according to another embodiment of the present invention. As shown in the ferrule 14 in FIG. 3, a tip of the ferrule 6 in FIG. 1 on the light emitting / receiving element side projects a part of the core of the optical fiber, and the tip is processed into a taper shape to increase the coupling efficiency.

FIG. 4 shows a semiconductor laser module according to claim 4 according to another embodiment of the present invention. As shown in a ferrule 15 in FIG. 4, a tip of the ferrule 6 in FIG. 1 on the light emitting / receiving element side projects a part of the core wire of the optical fiber, and the tip is processed into a spherical shape to improve the coupling efficiency.

FIG. 5 shows a semiconductor laser module according to claim 5 according to another embodiment of the present invention. The tip of the ferrule 6 on the light emitting and receiving element side in FIG. 1 uses a core diameter expansion fiber as an optical fiber as shown in a ferrule 16 in FIG.

FIG. 6 shows a photodiode module according to claim 6 according to another embodiment of the present invention. FIG.
The tip of the ferrule 6 on the side of the light emitting / receiving element is a multimode fiber as an optical fiber as shown in the ferrule 17 in FIG. 6, and the allowable error range is widened to facilitate the alignment.

The assembling method shown in FIGS. 2, 3, 4, 5, and 6 is performed in the same manner as the assembling shown in FIG.

[0017]

According to the present invention, by using a single ferrule as an intermediary for optical coupling, optical coupling can be achieved without using a lens, and by processing the shape of the ferrule tip, high efficiency can be easily achieved. Enables optical coupling.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts of a receptacle-type semiconductor laser module that optically couples a semiconductor laser and an optical fiber for signal transmission according to an embodiment of the present invention with a single ferrule as an intermediary.

FIG. 2 is a cross-sectional view of a main part of a semiconductor laser module in which an end surface of an optical element side of a ferrule for mediating optical coupling according to an embodiment of the present invention is obliquely polished.

FIG. 3 is a cross-sectional view of a main part of a semiconductor laser module in which an end surface of an optical element side of a ferrule for mediating optical coupling according to an embodiment of the present invention is processed into a tapered shape.

FIG. 4 is a cross-sectional view of a main part of a semiconductor laser module in which an end surface on the optical element side of a ferrule for mediating optical coupling according to an embodiment of the present invention is processed into a spherical shape.

FIG. 5 is a cross-sectional view of a main part of a semiconductor laser module in which an optical fiber on an end surface on the optical element side of a ferrule for mediating optical coupling according to an embodiment of the present invention is a core expansion fiber.

FIG. 6 is a cross-sectional view of essential parts of a photodiode module in which an optical fiber of a ferrule for mediating optical coupling according to an embodiment of the present invention is a multimode fiber.

FIG. 7 is a cross-sectional view of essential parts of a conventional semiconductor optical module in which a light emitting and receiving element and an optical fiber are optically coupled by a lens.

[Explanation of symbols]

1 ... Semiconductor laser, 2 ... Submount, 3 ... Stem, 4
... Lead terminal, 5 ... Ferrule holder, 6 ... Ferrule, 7 ... Ferrule, 8 ... Optical connector, 9 ... Optical fiber, 10 ... Spring, 11 ... Submount, 12 ... Photodiode, 13 ... Ferrule, 14 ... Ferrule, 15
... ferrule, 16 ... ferrule, 17 ... ferrule,
18 ... Photodiode for signal reception, 19 ... Light emitting diode element, 20 ... Optical fiber, 21 ... Optical fiber jacket,
22 ... Optical fiber terminal member, 23 ... Focusing rod lens, 24 ... Holding member, 25 ... Screw coupling part, 26A, 26
B, 26C, 26D ... Joining portion, 27 ... Holding member.

Claims (6)

[Claims] 1. In a semiconductor optical module having a function of transmitting, receiving or transmitting / receiving an optical signal, when the light emitting / receiving element and the signal transmitting optical fiber are arranged so as to have an optical transmission relationship, the light emitting / receiving element and the signal transmission are arranged. The ferrule attached to protect the tip of the optical fiber or to facilitate the processing of the tip shape between the optical fiber and the optical fiber is used only as an intermediary for the optical coupling between the light emitting / receiving element and the optical fiber for signal transmission. And the optical fiber for signal transmission are placed so that they have an optical transmission relationship with each other. Pigtail type and light emitting and receiving element package for signal transmission with the optical fiber for signal transmission and reception and the optical fiber for signal transmission are integrated. A semiconductor optical module in which an optical fiber is detachable. 2. The semiconductor optical module according to claim 1, wherein a tip of the ferrule on the light emitting and receiving element side is obliquely polished. 3. The semiconductor optical module according to claim 1, wherein a part of the fiber core wire is projected from the tip of the ferrule on the light emitting and receiving element side, and the tip of the projection is processed into a taper shape. 4. The semiconductor optical module according to claim 1, wherein a part of the fiber core wire is projected from the tip of the ferrule on the light emitting and receiving element side, and the tip of the projection is processed into a spherical shape. 5. The semiconductor optical module according to claim 1, wherein the fiber at the tip of the ferrule on the light emitting and receiving element side is a core diameter expansion fiber. 6. The semiconductor optical module according to claim 1, wherein the optical fiber portion of the ferrule is a multimode fiber.