JPH1010370A - Semiconductor laser module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the output of an LD module and to eliminate the need for a temp. characteristic inspection even if light emitting patterns change by constituting an optical fiber of a quartz optical fiber added with a metallic element absorbing the light emitted from a semiconductor laser module (LD) element in the core part of the optical fiber. SOLUTION: The LD element 12 installed in an LD element casing 11 for hermetically sealing the LD element, the quartz optical fiber 17 added with the metallic element, such as cobalt, in order to absorb the light emitted from the LD element 12 in the core part of the optical fiber for transmitting the light emitted from the LD element 12 to an optical transmission path coupled thereto and a coupling lens 14 for coupling the light emitted from the LD element 12 to the quartz optical fiber 17 are used as basic elements. The light emitted from the LD element 12 is coupled at several 10% of the light to the end face 17-a of the quartz optical fiber 17 via the coupling lens 14. The light made incident on the end face 17-a of the optical fiber is absorbed by the added metal in passing the quartz optical fiber 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser module (hereinafter abbreviated as an LD module) as a light source for optical communication.

[0002]

2. Description of the Related Art Conventionally, techniques in such a field include:
For example, there are the following. FIG. 4 is a sectional view of such a conventional LD module. As shown in FIG. 1, a conventional LD module includes an LD element 2 installed in an LD element housing 1 for hermetically sealing the LD element,
Basically, a silica-based optical fiber 3 for coupling the light emitted from the D element 2 and sending it out to the optical transmission line, and a coupling lens 4 for coupling the light emitted from the LD element 2 to the optical fiber 3 And an optical fiber holding member 9
And a housing member 5, which mechanically connects these basic elements,
6.

FIG. 5 shows a model in which the LD element 2 is coupled to the optical fiber 3 via the coupling lens 4. As shown in this figure, the light coupled to the optical fiber 3 is a part of the light emitted from the LD element 2. FIG. 6 shows the amount of light transmitted from the LD element to be coupled to the optical fiber by the light emission pattern of the LD element. FIG. 6A shows the case of an intra-station transmission LD module, in which the optical coupling amount is only a few percent, and the coupling portion to the optical fiber indicated by oblique lines has a very narrow angle.
FIG. 6B shows a case of an LD module for inter-station transmission.
Since the amount of optical coupling is as large as several tens of percent, the coupling portion to the optical fiber indicated by oblique lines extends over a very wide angle.

[0004]

However, in the structure of the conventional LD module, as shown in FIG. 6A, when the coupling angle to the optical fiber is small, the light emission pattern of the LD element 2 depends on the temperature. 6 (c) -1 to FIG. 6 (c) -2, the amount of coupling to the optical fiber changes, and stable optical transmission may not be possible.

For this purpose, a change in the light emission pattern of the LD element 2 alone is inspected by changing the temperature in advance,
The optical coupling amount of the module, which is inspected by changing the temperature by changing the temperature, is prevented from changing, and stable optical transmission is maintained. In any case, an inspection in which the temperature is changed is required, and the yield of the LD element or the LD module must be considered, which hinders supply of an inexpensive LD module to the apparatus.

According to the present invention, there is provided a semiconductor laser module capable of eliminating the above-mentioned problems, stabilizing the output of an LD module, improving the yield, and eliminating a temperature characteristic inspection step even if the light emission pattern changes with temperature. The purpose is to provide.

[0007]

To achieve the above object, the present invention provides: [1] An LD element, an optical fiber, a coupling lens for optically coupling them, and a member for mechanically coupling them. In the LD module, the optical fiber comprises a silica-based optical fiber in which a metal element for absorbing light emitted from the LD element is added to an optical fiber core.

Therefore, since a coupling system of several tens of percent can be selected to obtain a light output of several percent, a wide range of the light emitting pattern of the LD element can be used.
Further, even if the light emission pattern changes with temperature, the output of the LD module is stable, the yield is improved, the temperature characteristic inspection step can be omitted, and an inexpensive LD module can be provided.

[2] In an LD module comprising an LD element, an optical fiber, and a member for mechanically coupling them,
The optical fiber is a silica-based optical fiber obtained by subjecting an end face of an optical fiber core portion to a spherical lens processing and adding a metal element for absorbing light emitted from the LD element. Therefore, the effect of the above [1] can be obtained, and the coupling lens is eliminated, and instead, the end face of the optical fiber core is processed with a spherical lens, so that the semiconductor laser module is made compact and The size can be reduced.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view of an LD module according to a first embodiment of the present invention. This LD
The module is an LD element housing 1 that hermetically seals the LD element.
1 and an optical fiber core for coupling the light emitted from the LD element 12 and sending the light to the optical transmission line, a metal such as cobalt for absorbing the light emitted from the LD element 12. A quartz optical fiber 17 doped with an element and a coupling lens 14 for coupling the light emitted from the LD element 12 to the quartz optical fiber 17 are used as basic elements. Further, the optical fiber holding member 19 and housing members 15 and 16 for mechanically connecting these basic elements are constituted.

In this embodiment, the light emitted from the LD element 12 is coupled to the end face 17-a of the silica-based optical fiber 17 via the coupling lens 14 by several tens% of the light emitted from the LD element 12. The light that has entered the optical fiber end face 17-a is absorbed by the metal added to the quartz optical fiber 17 when passing through the quartz optical fiber 17. When emitted from b, it is several% of the emitted light from the LD element 12.

As described above, according to the first embodiment, it is possible to select a coupling system of several tens% in order to obtain an optical output of several percent, and as shown in FIG. Element 12
Since the light emitting pattern can be used in a wide range, even if the light emitting pattern changes with temperature, the output of the LD module is stable, the yield is improved, and the temperature characteristic inspection process can be eliminated. Modules can be supplied to the device.

Next, a second embodiment of the present invention will be described. FIG. 2 is a sectional view of an LD module according to a second embodiment of the present invention, and FIG. 3 is a view showing an end face structure of a fiber of the LD module. This LD module includes an LD element 22 installed in an LD element housing 21 for hermetically sealing the LD element.
And a silica-based optical fiber 28 in which a metal element such as cobalt is added to an optical fiber core for coupling the light emitted from the LD element 22 and transmitting the light to the optical transmission line, in order to absorb the light emitted from the LD element 22. Is the basic element. Further, it comprises an optical fiber holding member 29 and a housing member 26 for mechanically connecting these basic elements. Here, the end face 28-a of the silica fiber is subjected to spherical lens processing as shown in FIG. 3 in order to enhance the coupling with the LD element 22.

In this embodiment, light emitted from the LD element 22 is emitted from the LD element 22 to the quartz optical fiber 28 via the optical fiber end face 28-a of the quartz optical fiber 28 which has been subjected to spherical lens processing. Several tens% of the emitted light is coupled. Optical fiber end face 2 with this spherical lens processing
Since the light incident on 8-a is absorbed by a metal such as cobalt added to the optical fiber when passing through the optical fiber 28, when emitted from the other end surface 28-b of the optical fiber 28, This is several percent of the light emitted from the LD element 22.

As described above, according to the second embodiment, in order to obtain an optical output of several percent, a coupling system of several tens percent can be selected. As shown in FIG. Since a wide range of the light emission pattern of the element can be used, even if the light emission pattern changes with temperature, the output of the LD module is stable, the yield is improved, the temperature characteristic inspection process can be reduced, and the cost can be reduced. An LD module can be obtained.

Further, according to this embodiment, since the spherical lens is provided on the end face of the optical fiber core instead of the coupling lens, the semiconductor laser module can be reduced in size and size. Further, according to the present invention, the following utilization forms are provided. In the first and second embodiments, the optical fiber fixed to the optical fiber holding member is integrated with the LD element by a housing, but the receptacle LD module in which the LD element and the optical fiber are separated, and the receptacle It goes without saying that the present invention does not impair the effectiveness of the present invention even in the case of a combination of a quartz-based optical fiber doped with a metal element and held by an optical connector fitted to the optical connector.

It should be noted that the present invention is not limited to the above embodiment, and various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0018]

As described above, according to the present invention, the following effects can be obtained. (1) According to the first aspect of the present invention, it is possible to select a coupling system of several tens% in order to obtain a light output of several%, so that a wide range of the light emitting pattern of the LD element can be used. it can.

Therefore, even if the light emission pattern changes with temperature, the output of the LD module is stable, the yield is improved, the temperature characteristic inspection step can be omitted, and an inexpensive LD module can be provided. (2) According to the second aspect of the invention, the effect of the above (1) can be obtained, and the coupling lens is eliminated.
Instead, the end face of the optical fiber core is subjected to spherical lens processing, so that the semiconductor laser module can be made compact and small.

[Brief description of the drawings]

FIG. 1 is a sectional view of an LD module according to a first embodiment of the present invention.

FIG. 2 is a sectional view of an LD module according to a second embodiment of the present invention.

FIG. 3 is a diagram showing an end face structure of a fiber of an LD module according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of a conventional LD module.

FIG. 5 is a diagram illustrating a model in which an LD element is coupled to an optical fiber via a coupling lens.

FIG. 6 is a light emission pattern diagram of an LD element showing an amount of light transmitted from the LD element that is coupled to an optical fiber.

[Explanation of symbols]

 11, 21 LD element housing 12, 22 LD element 14 Coupling lens 15, 16, 26 Housing member 17, 28 Silica-based optical fiber 17-a, 17-b, 28-b Optical fiber end face 19 Optical fiber holding member 28 −a Optical fiber end face with spherical lens processing 29 Optical fiber holding member

Claims (2)

[Claims] 1. An LD module comprising an LD element, an optical fiber, a coupling lens for optically coupling them, and a member for mechanically coupling them, wherein the optical fiber emits light from the LD element to an optical fiber core. An LD module comprising a quartz optical fiber doped with a metal element for absorbing light. 2. An LD module comprising an LD element, an optical fiber, and a member that mechanically couples the LD element, wherein the optical fiber is subjected to spherical lens processing on an end face of an optical fiber core portion, and light emitted from the LD element. An LD module comprising a silica-based optical fiber doped with a metal element for absorbing light.