JPH0511216A - Semiconductor module - Google Patents

Abstract

PURPOSE:To obtain the economical semiconductor laser module by eliminating the need for a polarized wave multiplexer which is conventionally required to multiplex two light beams, reducing the light loss of a system, and simplifying the constitution of an optical fiber amplifier. CONSTITUTION:A 1st semiconductor laser 11 emits 1st laser light. A 2nd semiconductor laser 12 emits 2nd laser light which crossing the 1st laser light at right angles. A polarization beam splitter 4 outputs the light beam composed of the 1st and 2nd incident laser light beams. The optical fiber 50 is constituted so as to transmit the incident light beam.

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 used for optical communication and optical information processing.

[0002]

2. Description of the Related Art A conventional semiconductor laser module is shown in FIG.
As shown in FIG. 5, the lens 24 is configured to include a lens 24 that converges the light emitted from the semiconductor laser 13, and an optical fiber 51 that receives the light converged by the lens 24.

When an optical signal is transmitted by the optical fiber 51, the intensity of the optical signal is attenuated with the transmission distance due to the transmission loss of the optical fiber. For this reason, the optical fiber communication systems currently put into practical use use a repeater for amplifying an optical signal attenuated at a constant distance. Since this relay device has a configuration in which an optical signal is once converted into an electric signal, the signal is amplified, and then converted into an optical signal again to be sent out, the device becomes bulky and expensive. Therefore, in recent years, studies have been conducted on optical direct amplification using a rare earth-doped fiber (a method for directly obtaining an amplified optical signal from an optical signal). As shown in FIG. 3, an amplifier using a rare earth-doped fiber (hereinafter abbreviated as fiber amplifier) is a semiconductor laser module 80 for excitation for exciting the rare earth-doped fiber 7 and rare earth ions in the fiber 7 to cause stimulated emission. And a coupler 6 for guiding the light emitted from the pumping semiconductor laser module 80 to the rare earth-doped fiber 7.
However, the optical output power required for the pumping semiconductor laser module 80 is as high as about 100 mW, and there is a drawback that a high-output semiconductor laser is required.

Therefore, in the semiconductor laser module as shown in FIG. 2, in order to obtain a desired optical output, as shown in FIG. 4, two semiconductor laser modules 81 and 82 using a polarization maintaining fiber as the optical fiber 51 are used. The polarization combiner 9 merges the output lights into one optical fiber, and the optical power is added. Generally, in a semiconductor laser module and a polarization combiner, an optical system for optically coupling between a semiconductor laser and an optical fiber and between an optical fiber for optical input and output is used, respectively. The light loss at has a finite value, not zero.

[0005]

In the conventional semiconductor laser module described above, the semiconductor laser module 8 is used.
The radiated light from the semiconductor lasers inside 1 and 82 is attenuated inside the semiconductor laser module and inside the polarization combiner before reaching the coupler 6, which has a drawback that the efficiency is low. In addition, the configuration using two semiconductor laser modules and a polarization beam combiner is complicated and expensive.

[0006]

A semiconductor laser module according to the present invention includes a first semiconductor laser emitting a first laser beam and a second laser beam emitting a second laser beam orthogonal to the first laser beam. 2 semiconductor lasers and the first laser beam incident
And a second beam of laser light combined to output a light beam, and an optical fiber that transmits the incident light beam.

[0007]

The present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a semiconductor laser module of the present invention.

In FIG. 1, the first semiconductor laser 11 is shown.
Emits a first laser beam. Second semiconductor laser 1
2 emits a second laser light which is orthogonal to the first laser light. The polarization beam splitter 4 receives the first and second incident beams.
And outputs a light beam merged with the laser light of. The optical fiber 50 transmits the incident light beam.

Next, the operation of this embodiment will be described. The semiconductor lasers 11 and 12 which are the first and second semiconductor lasers are provided with lenses 21 and 22 for collimating the emitted light from the respective semiconductor lasers. They are provided and attached to the case 3 so that their optical axes are orthogonal to each other and the polarization directions of emitted light are also orthogonal to each other. Inside the case 3, a polarization beam splitter 4 is fixed at the intersection of the emitted beams of the semiconductor lasers 11 and 12, and the beams of the semiconductor lasers 11 and 12 are combined into one beam inside the polarization beam splitter 4. It is coupled to the optical fiber 50 via the lens 23.

As described above, since the polarization beam splitter is inserted in the two sets of lens coupling system from the semiconductor laser to the optical fiber, the polarization combiner conventionally used as the beam combining means becomes unnecessary, and the system is eliminated. Can reduce the loss.

[0011]

As described above, the present invention has the polarization beam splitter in the coupling optical system of the semiconductor laser and the optical fiber, and combines the emitted lights from the two semiconductor lasers into one light beam. The introduction to the fiber eliminates the need for a polarization combiner conventionally required for merging two light beams, and has the advantage of reducing optical loss in the system. Moreover, since the outputs from the two semiconductor lasers can be efficiently guided to the rare earth-doped fiber, the structure of the optical fiber amplifier is simple and economical.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a plan view of an example of a conventional semiconductor laser module.

FIG. 3 is a block diagram of an optical direct amplifier according to a conventional example.

FIG. 4 is a block diagram of an optical direct amplifier according to a conventional example.

[Explanation of symbols]

 3 Case 4 Polarizing Beam Splitter 6 Coupler 7 Rare Earth Doped Fiber 9 Polarization Synthesizer 11, 12, 13 Semiconductor Laser 21, 22, 23, 24 Lens 50, 51 Optical Fiber 80, 81, 82 Semiconductor Laser Module

Claims (1)

Claims: 1. A first semiconductor laser that emits a first laser light, and a second semiconductor laser that emits a second laser light orthogonal to the first laser light, A semiconductor laser module, comprising: a polarization beam splitter that outputs a light beam obtained by combining the incident first and second laser lights, and an optical fiber that transmits the incident light beam.