JPH06152069A - Semiconductor laser array module - Google Patents

Abstract

PURPOSE:To provide a semiconductor laser array module allowing removal of leak light from the other channel to a photo detector. CONSTITUTION:A plurality of semiconductor laser elements 1A to 1F composing a semiconductor laser array 1 are arranged respectively at the regular intervals in the vertical direction to an optical axis and in parallel so as to emit the main beam light 4A to 4F in one direction of this optical axis while emitting monitor beam light 5A to 5f in the inverse direction of the optical axis. The optical fibers 2A to 2F constituting an optical fiber array 2 combine the main beam light 4A to 4F while the photo detecctors 3A to 3F constituting a photo detector array combine monitor beam light 5A to 5F for performing level detection of this combined monitor beam light. The narrow zone light band path filters 6A to 6F having the mutually different transmitting frequencies are arranged in the front of the photo detectors 3A to 3F for preventing incident of leak light from the other channel to the photodetectors 3A to 3F.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser array module, and more particularly to a semiconductor laser array module used as a light source for optical frequency division multiplexing communication.

[0002]

2. Description of the Related Art Optical frequency division multiplex communication is being studied as a large capacity optical communication system in the future, but a transmitter thereof requires a plurality of light sources having different wavelengths for each channel. In this case, using a semiconductor laser array in which a plurality of semiconductor lasers are integrated is extremely advantageous for downsizing the device and saving power.

FIG. 3 is a top view showing the structure of a conventional semiconductor laser array module including this semiconductor laser array. This semiconductor laser array module includes a semiconductor laser array 1 composed of six semiconductor lasers 1A to 1F arranged at equal intervals, and six single-mode front balls arranged in an array at equal intervals with the semiconductor laser array 1. An optical fiber array 2 including processed optical fibers 2A to 2F, and a light receiving element array 3 including six light receiving elements for detecting emitted light, which are arranged at equal intervals with the semiconductor laser array 1, are provided. There is.

In the semiconductor laser array module of FIG. 3, the main beams 4A to 4A emitted from the semiconductor lasers 1A to 1F are coupled to the optical fibers 2A to 2F of the single-mode front sphere processing for each channel. There is. Further, the semiconductor laser 1 emitted from the semiconductor laser array 1 in a direction opposite to the side where the optical fiber array 2 for single mode front sphere processing is located.
The respective monitor beams 5A to 5F from A to 1F are
The light receiving elements 3A to 3F for detecting emitted light are respectively coupled.

[0005]

Usually, in order to make the optical output from the optical fiber on the transmitter side constant, the output voltage detected from the monitor beam by the detection light receiving element is compared with the reference voltage by the differential amplifier. However, the automatic light output control (Automatic Power C) that changes the bias current flowing through the semiconductor laser so that the difference is constantly 0
control (APC) circuit is used. However,
In the above-mentioned semiconductor laser array module using the conventional technique, the detection light receiving element of each channel not only receives the monitor beam from each channel of the opposing semiconductor laser but also the monitor beam from the adjacent semiconductor laser. Since light is received, the optical output of each channel is not proportional to the output voltage of the detection light receiving element, and the optical output of each channel cannot be made constant by the APC circuit.

Therefore, it is an object of the present invention to eliminate the leakage light from the other channels to the light receiving element so that the optical output can be controlled to be constant in each channel by the APC circuit. To provide an array module.

[0007]

A semiconductor laser array module of the present invention is arranged side by side in a direction perpendicular to an optical axis, emits a main beam light in one direction of the optical axis, and reverses the optical axis. A plurality of semiconductor laser elements that emit monitor beam light, an optical fiber that couples each of the main beam lights from the plurality of semiconductor laser elements, and the monitor beam light from each of the plurality of semiconductor laser elements. In a semiconductor laser array module including a light receiving element that is coupled to detect the level of the coupled monitor beam light, the light receiving element that couples the plurality of semiconductor laser elements and the respective monitor beam light from these semiconductor laser elements. And a narrow band optical band pass filter having different transmission frequencies from each other.

[0008]

The present invention will be described below with reference to the drawings.

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

In FIG. 1, the oscillation peak wavelength of the light emitted from each channel of the semiconductor laser array 1 (main beams 4A to 4F and monitor beams 5A to 5F) is the semiconductor laser 1A.
To 1F, 1.546μm, 1.548, respectively
μm, 1.550 μm, 1.552 μm, 1.554 μ
m and 1.556 μm. Further, the total light wavelength width at −30 dB from the peak of the emitted light is 0.5 nm or less for all channels. Next, the semiconductor laser 1A
The behaviors of the monitor beams 5A to 5F emitted from 1F to 1F in the opposite direction to the side where the optical fiber array 3 is present will be described with the semiconductor laser 1C as a representative. Monitor beam 5C emitted from semiconductor laser 1C (oscillation wavelength: 1.550μ
m) is included in the optical bandpass filter array 6, has a central wavelength of 1.550 μm, and has a total optical wavelength width of 2n at −10 dB.
The light passes through the narrow band optical bandpass filter 6C of m or less and enters the light receiving element 3C for detecting the monitor beam.

FIG. 2 is a transmission characteristic diagram of the narrow band optical bandpass filter 6C described above.

The monitor beam 5B (oscillation wavelength 1.548 μm) emitted from the semiconductor laser 1B is suppressed from leaking into the light receiving element 3C by the narrow band optical bandpass filter 6C. The monitor beams 5A, 5D to 5F emitted from the semiconductor lasers 1A, 1D to 1F are similarly suppressed from leaking into the light receiving element 3C by the narrow band optical bandpass filter 6C. Semiconductor lasers 1A, 1B, 1
Monitor beams 5A and 5A respectively emitted from D to 1F
The behaviors of B, 5D to 5F are similar, and the monitor beams emitted from the respective semiconductor lasers are incident on the detection light receiving element for each channel without leaking into other channels.

In the embodiment of FIG. 1, the main beam emitted from the semiconductor laser and the single-mode optical fiber are coupled by using a spherical optical fiber, but the coupling method is not limited to this. Alternatively, a lens or the like may be used.

Further, although the element intervals are equal in FIG. 1, they are not limited to this. A plurality of narrow band optical band pass filters 6 constituting the optical band pass filter array 6
A to 6F are also arranged as an example, but the arrangement is not limited to this.

The wavelength band of the semiconductor laser array 1 and the narrow band optical bandpass filter array 6 is 1.55 μm.
However, the wavelength interval of each channel is set to 2 nm, but the present invention is not limited to this. Further, the narrow band optical bandpass filters 6A to 6F each have a transmission width of 2 nm or less at −10 dB, but the transmission width is not limited to this. Any material may be used as long as it has a transmission characteristic capable of limiting the leakage light to the element to a negligible level.

[0016]

As described above, the semiconductor laser array module of the present invention is a narrow band optical bandpass filter having different transmission frequencies between a plurality of semiconductor lasers and a photodetection light receiving element facing each of them. By arranging, there is an effect that the monitor beam of each channel emitted from each semiconductor laser can be made incident on the detection light receiving element for each channel without leaking into the other channels. Therefore, when this semiconductor laser array module is used in an APC circuit, it becomes possible to control the optical output constant for each channel.

[Brief description of drawings]

FIG. 1 is a top view showing an embodiment of a semiconductor laser array module according to the present invention.

FIG. 2 is a transmission characteristic diagram of a narrow band optical bandpass filter 6C in the embodiment of FIG.

FIG. 3 is a top view showing a configuration of a conventional semiconductor laser array module.

[Explanation of symbols]

 1 semiconductor laser array 1A-1F semiconductor laser 2 optical fiber array 2A-2F optical fiber 3 light receiving element array 3A-3F light receiving element 4A-4F main beam 5A-5F monitor beam 6 optical bandpass filter array 6A-6F narrow band optical band Pass filter

Claims (2)

[Claims] 1. A plurality of semiconductor laser devices which are arranged side by side in a direction perpendicular to an optical axis and emit a main beam light in one direction of the optical axis and emit a monitor beam light in a direction opposite to the optical axis. An optical fiber that couples the respective main beam lights from the plurality of semiconductor laser devices and a respective one of the monitor beam lights from the plurality of semiconductor laser devices are coupled to detect the level of the coupled monitor beam lights. In a semiconductor laser array module including a light receiving element for performing narrow band light having mutually different transmission frequencies between the plurality of semiconductor laser elements and the light receiving elements for coupling the respective monitor beam lights from these semiconductor laser elements. A semiconductor laser array module comprising a bandpass filter. 2. The plurality of semiconductor laser elements are arranged side by side at regular intervals, and the optical fiber and the light receiving element respectively facing the plurality of semiconductor elements are also:
The semiconductor laser array module according to claim 1, wherein the semiconductor laser array modules are arranged at the intervals.