JPH07234338A - Optical element module - Google Patents

Abstract

PURPOSE:To improve optical stability which deserves thermal stress and to reduce the operation cost by providing an optical output monitor device consisting of an optical isolator, a beam splitter, an output 2nd lens, and a photodetector for monitoring in one body. CONSTITUTION:An optical amplifying element 1, 1st lenses 4a and 4b, and a thermistor 5 are mounted at specific positions on a stem 6, whose the bottom surface is fixed to the cooling surface of a thermionic cooling element 7; and the thermionic cooling element 7 united with the stem 6 is fixed to the bottom surface in a case 8. After an input optical fiber 2 and the 2nd lens 9a are positioned so that the efficiency of optical coupling with the optical amplifying element 1 becomes maximum, a lens holder 10 is fixed to the input-side flank of the case 8 and a fiber holder 12 is fixed to an end part of the lens holder 10. Then the optical isolator 13, beam splitter 14, 2nd lens 9b, and photodetector 16 are fixed at specific positions on a cylindrical support member 15 and united with a high-strength connecting member such as Au/Ge solder or Au/Sn solder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical amplifier module for optical communication and an optical modulator module.

[0002]

2. Description of the Related Art In a conventional optical amplifier module, an optical isolator is inserted between a first lens and a second lens in order to block return light due to reflection of light from the outside and stabilize the operation. JP-A-4-156432). Also,
In the conventional optical amplifier module with optical output monitor, a beam splitter is inserted between the output first lens and the output second lens, the light intensity branched by the beam splitter is detected by the light receiving element, and the optical output is monitored. (Japanese Patent Laid-Open No. 4-
39632).

[0003]

In the above-mentioned conventional example, a two-lens optical coupling system is used in order to increase the optical coupling efficiency. However, the optical isolator or beam splitter and the output second lens are separated from each other. Since the optical axis is fixed due to the change in the ambient temperature, the optical axis shifts due to thermal expansion and contraction, and the positional shift of the fixed part due to repeated thermal stress easily occurs.
There is a problem that it causes deterioration of optical coupling efficiency. Further, since the number of optical components increases, there is a problem that the number of assembling steps and working time increase.

An object of the present invention is to provide an optical element module which enables stable operation of the optical element, a built-in optical output monitor, high stability against thermal stress of optical coupling, and simplification of assembling. .

[0005]

In order to achieve the above-mentioned object, the present invention provides a two-lens optical coupling system in which an optical isolator and a beam splitter are inserted between the output first lens and the output second lens. The optical output monitor device includes an optical isolator, the beam splitter, the output second lens, and an output monitor light receiving element that receives the branched light from the beam splitter.

[0006]

The optical isolator removes the return light due to the reflection of light from the outside and stabilizes the operation of the optical element. Further, the optical intensity of the branched light from the beam splitter is detected by the light receiving element, and the optical fiber output can be monitored by monitoring the detection output of the light receiving element. The optical isolator, the beam splitter, the output second lens, and the light receiving element are adjusted in optical axis and fixed to the case by integrating them by a cylindrical support member, thereby collectively adjusting the optical axis and fixing them to the case. It becomes possible to simplify the assembling. Further, with respect to thermal stress, the optical isolator, the beam splitter, the output second lens, and the light receiving element are integrally moved in the cylindrical support member, and the relative position between the optical components is changed. Since the fluctuation is small, the deviation of the optical axis and the deviation of the focus are small, and the stability of the optical coupling is high.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention is shown in FIGS.
Will be described.

1A and 1B are a horizontal sectional view and a vertical sectional view, respectively, of an optical element module using an optical amplification element 1 as an optical element. The optical amplification element 1, the first lenses 4a and 4b, and the thermistor 5 are mounted at predetermined positions on the stem 6, and the bottom surface of the stem 6 is fixed to the cooling surface of the thermoelectric cooling element 7 so as to be integrated with the stem 6. The cooled thermoelectric cooling element 7 is fixed to the bottom surface of the case 8. The second lens 9a is fixed to the lens holder 10 with An / Sn solder, and the lens holder 1
No. 0 is fixed to the input side surface of the case 8 by YAG laser welding. The input optical fiber 2 with the ferrule 11 is supported by the fiber holder 12, and the fiber holder 12 is fixed to the end of the lens holder 10 with Au / Sn solder. However, after aligning the input optical fiber 2 and the second lens 9a so that the optical coupling efficiency with the optical amplification element 1 is maximized, the lens holder 10 is fixed to the input side surface of the case 8, and the fiber holder 12 Is fixed to the end of the lens holder 10. Optical isolator 13 and beam splitter 1
4, the second lens 9b and the light receiving element 16 are fixed to a predetermined position of the cylindrical support member 15 with a high-strength joining member such as Au / Ge solder or Au / Sn solder, and are integrated. With this structure, the relative positional fluctuation between the optical components due to thermal stress is reduced, and the stability of optical coupling is increased. The cylindrical support member 15 is welded to the output side surface of the case by a YAG laser, and the fiber holder 12 supporting the output optical fiber 3 with the ferrule 11 is fixed to the end of the cylindrical support member 15 with Au / Sn solder. is doing.
The cylindrical support member 15 and the fiber holder 12 are aligned so that the optical coupling efficiency between the optical amplification element 1 and the output optical fiber 3 is maximized, and then the cylindrical support member 15 is placed on the output side surface of the case 8. Then, the fiber holder 12 is fixed to the end of the cylindrical support member 15. As described above, the optical axes of the optical isolator 13, the beam splitter 14, the second lens 9b, and the light receiving element 16 are adjusted by the cylindrical support member 15.
Since it can be performed collectively by adjusting the optical axis, the number of steps for assembling output side optical components can be reduced to half that of conventional products.
Can be reduced to

The signal light incident from the input optical fiber 2 is
It is converted into parallel light by the second lens 9a, and this parallel light is condensed by the first lens 4a and is coupled to the optical amplification element 1. The output light amplified by the optical amplification element 1 is converted into parallel light by the first lens 4b, passes through the optical isolator 13 and the beam splitter 14, is condensed by the second lens 9b, and is coupled to the output optical fiber 3. Of the parallel light that has entered the beam splitter 14, 5% is split perpendicularly to the optical axis and is incident on the light receiving element 16 and detected. By monitoring the detection output of the light receiving element 16, the fiber light output can be monitored.

A second embodiment of the present invention is shown in FIG.

FIG. 2 shows a light receiving element 1 of the embodiment shown in FIG.
6 is mounted on the subcarrier 18 together with the spherical lens 17, and is fixed on the optical axis of the split light split by the beam splitter 14. The split light split by the beam splitter 14 is condensed by the spherical lens 17 and enters the light receiving element 16. By monitoring the detection output of the light receiving element 16, the fiber light output can be monitored.

3 and 4, the fluctuation rate of the fiber optical output when the optical element module is driven so that the detection output of the light receiving element 16 becomes constant and the environmental temperature is changed from -20 degrees to +65 degrees. Indicates. FIG. 3 shows the fiber light output fluctuation rate of the conventional product, and FIG. 4 shows the fiber light output fluctuation rate of the present embodiment.

This embodiment is different from the conventional product in that the optical isolator 13, the beam splitter 14, the output second lens 9b,
Since the light receiving element 16 is integrated and the relative position fluctuation due to thermal stress is small, the deterioration of the optical coupling efficiency is small, and the fiber light output fluctuation rate is suppressed to 10% or less.

[0014]

As described above, according to the present invention, since the optical output monitor device in which the optical isolator, the beam splitter, the output second lens, and the monitor light receiving element are integrated is provided, the optical element operates stably, The fiber light output can be monitored and the optical stability against thermal stress can be increased. For example, the optical element module is driven so that the detection output of the light receiving element is constant, and the ambient temperature is
It is possible to suppress the variation rate of the fiber light output when varying from 20 degrees to +65 degrees to 10% or less. Also,
By integrating the above-mentioned optical components, the number of assembling steps of the output-side optical components can be reduced to 1/2, and the work cost can be reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention, in which (a) is a horizontal sectional view and (b) is a vertical sectional view.

FIG. 2 is a cross-sectional view of the second embodiment of the present invention.

FIG. 3 is a diagram showing a fiber optical output fluctuation rate of a conventional product.

FIG. 4 is a diagram showing a fiber light output fluctuation rate in the present embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical amplification element, 2 ... Input optical fiber, 3 ... Output optical fiber, 4a, 4b ... 1st lens, 5 ... Thermistor, 6 ...
Stem, 7 ... Thermoelectric cooling element, 8 ... Case, 9a, 9b
... second lens, 10 ... lens holder, 11 ... ferrule, 12 ... fiber holder, 13 ... optical isolator, 1
4 ... Beam splitter, 15 ... Cylindrical support member, 16 ...
Light receiving element, 17 ... Spherical lens, 18 ... Sub carrier.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Aoki 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Stock company Hitachi Information & Communication Division

Claims (3)

[Claims] Claim: What is claimed is: 1. An input first lens for condensing input light incident on the optical amplification element as parallel light or pseudo parallel light on an active layer of the optical amplification element and output light of the optical amplification element are parallel light or pseudo light. A stem equipped with an output first lens for converting into parallel light, an input optical fiber, and an output optically converted from the output light of the input optical fiber into parallel light or pseudo-parallel light, and an input optically coupled with the input first lens. A second lens, an output second lens for collecting parallel light or pseudo-parallel light converted by the output first lens, and output light optically coupled to the optical amplification element by the output first and second lenses An optical element module comprising a fiber and a case for accommodating and fixing the above-mentioned components, wherein the optical element is an optical amplification element, and an optical isolator and a beam splitter are provided between the output first lens and the output second lens. In the inserted configuration, the optical isolator, the beam splitter, the output second lens, and an optical output monitor device that integrates the light receiving element for output monitoring that receives the branched light by the beam splitter are integrated. Optical element module. 2. A light receiving element for output monitoring according to claim 1, wherein an optical isolator, a beam splitter and an output second lens are integrated instead of the optical output monitoring device, and the branched light split by the beam splitter is on the optical axis. An optical element module comprising an optical output monitor in which is arranged. 3. An optical element module according to claim 1 or 2, wherein the optical element is an optical modulation element instead of an optical amplification element.