JPH02291510A - Optical coupler - Google Patents

Abstract

PURPOSE:To allow the easy coupling of an optical device and optical fibers with high accuracy by providing a recessed part and grooves which are equal in depth and shape to each other, extend on a common straight line and are formed from the respective opposite sides of the recessed part to the recessed part on the prescribed surface of a base member thereby aligning the central axes of paired optical fibers. CONSTITUTION:The base member 11, the recessed part 11b formed on the prescribed surface of the base member 11, and one or plural pairs of the grooves 11c, 11d which are equal in depth and shape to each other, extend on the common straight line and are formed from the respective opposite sides of the recessed part 11b to the recessed part 11b are provided. One or plural pairs of the optical fibers 16, 17 which are installed in these grooves in such a manner that the ends thereof face each other and the optical device 14 which have optical coupling end faces 14a, 14b on the outer periphery and is provided in the recessed part 11b so as to optically connect the optical fibers 16, 17 to the optical coupling end faces are provided. The central axes of the optical fiber are aligned to each other in this way and the optical connection of the optical coupling end faces of an optical amplifier chip and the optical fiber is easily executed with the high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical coupler for coupling an optical element such as an optical amplifier to an optical fiber.

[Conventional technology]

FIG. 2 is a schematic longitudinal cross-sectional view showing a conventional optical amplification module with a Jf4 configuration.

In the figure, 1 is a base member having a flat part 1a and a recessed part 1b, 2 is a heat sink fixed to the four parts 1b of the base member 1 with a brazing agent 3, and 4 is a heat sink fixed on the heat sink 2 with a brazing agent 5. It is an optical amplification chip. Also,
Reference numerals 6 and 7 denote optical fibers, which are fixed onto the flat surface 1a of the base member 1 with an adhesive 8.9 so that their ends 6a and 7a are connected to the connection end surfaces 4a and 4b of the optical amplification chip 3. There is.

The optical amplification chip 4 is a semiconductor laser with anti-reflection coating applied to both light emitting end faces, and emits light by passing a current between the electrodes (not shown), and also emits light into the active layer which is the light emitting part. By injecting it, a photodetecting current flows. Therefore, conventionally, the optical fiber 6.7 and the optical amplification chip 4
When positioning, the optical amplification chip 4 emits a constant amount of light, the optical fiber 6.7 is moved in the x, y, and Z axis directions,
The optical fiber 6.7 was fixed after adjusting its relative position so that the amount of optical coupling with the optical amplification chip 4 was maximized. In addition, as for the procedure of Ike, while outputting a certain amount of light from the end face of the optical fiber 6.7,
, in the Z-axis direction, and after adjusting the relative position of the optical amplifying chip 4 so that the light-receiving current of the optical amplifying chip 4 is maximized, the optical amplifying chip 4 and the optical fiber 6.7 are fixed.

In this way, the relative positional relationship between the optical amplification chip 4 and the optical fiber 6.7 becomes a problem because the optical amplification module is -
In order to obtain an optical output of -12 dBm for an optical input of 20 dBm, with an optical amplification gain of +8 dB, for example, when using a single mode optical fiber whose tip diameter R is processed to 15 μm, This is because it is necessary to keep the variation in the amount of optical coupling within -1 dB when fixed. For this purpose, it is necessary to fix the optical fiber with a positional accuracy of 1 μm or less.

[Problem to be solved by the invention]

However, in the above conventional example, the optical fibers 6 and 7 are independently fixed to the base member 5, and the optical fiber 6
．． Since the central axes of the optical fibers 6 and 7 are misaligned, there is a problem in that it is difficult to install the optical amplification chip 4 between the optical fibers 6 and 7 so as to obtain a satisfactory coupling amount.

In addition, in order to satisfy the high optical amplification characteristics of the optical amplification module, it is necessary to fix the optical fiber within a -1 dB fluctuation range.
Due to the optical axis angle misalignment between the optical fiber 6 and the optical amplification chip 4 (-0.5 dB due to an angular misalignment of 5 degrees)
(causing optical coupling fluctuations) with respect to the angular axis θ. It is also necessary to adjust ψ for both optical fibers 6 and 7. For this reason, highly accurate optical adjustment of 1 μm or less and fixing must be performed twice each, which increases the number of manufacturing steps.
Another problem was that adjustment was difficult.

Therefore, the present invention has been made to solve the problems of the prior art as described above, and its purpose is to:
It is an object of the present invention to provide an optical coupler that allows simple and highly accurate coupling of an optical element and an optical fiber.

[Means to solve the problem]

In the optical coupler according to the present invention, a base member, four parts formed on a predetermined surface of the base member, and four parts formed on a predetermined surface of the base member have the same depth and shape, and are arranged on a common straight line. one or more pairs of fibers extending from opposite sides of the recess to the recess; one or more pairs of optical fibers installed in the well so that their ends face each other; It is characterized by having an optical coupling end face, and an optical element provided in the four parts so that the optical fiber is optically connected to the optical coupling end face.

[For production]

In the present invention, a recess is provided on a predetermined surface of the base member;
The grooves have one or more pairs of grooves having the same depth and shape, extending on a common straight line, and communicating with the recess from opposite sides of the recess. Therefore, by installing the optical fibers at the ends of the pair, the central axes of the pair of optical fibers are aligned. For this reason, it is best to install optical elements between a pair of optical fibers whose central axes are aligned.
The optical connection between the optical coupling end face of the optical element provided in the recess and the optical fiber can be easily performed and the optical connection can be made with high accuracy.

〔Example〕

The present invention will be explained below based on the illustrated embodiments.

FIGS. 1(a) and 1(b) are schematic plan views showing an optical amplification module which is an embodiment of an optical coupler according to the present invention, and its I.
-I line sectional view.

In the figure, 11 is a base member made of a material with a small coefficient of thermal expansion, such as ceramic, and a predetermined surface 11a of this base member 11 has a recess 1lb having the same depth and shape. The recesses 11a extend on a common straight line and tend to extend from opposite sides of the recess 11a to each other.
A pair of grooves 11c and lid are formed so as to communicate with each other.

Further, 12 is a waxing agent 13 in the recess 11b of the base member 11.
14 is the heat sink 1 fixed by
2, a light amplification chip 16 fixed by a waxing agent 15;
and 17 are single mode optical fibers which have been processed to have a spherical tip with a diameter of 125 μm and are installed in the V-grooves 11c, 11, d with their tips facing each other. Each optical fiber 16.1
7 is fixed to the base member 11 with an adhesive 21 such as low melting point glass, with its ends 16a and 17a facing each other.

The optical connection end faces 14a, 14b of the optical amplification chip 14 placed between the optical fibers 16.17 are optically connected to the end portions 16a, L7a of the optical fibers 16.17.

The manufacturing process of the optical amplification module having the above configuration will be explained based on FIG. By removing the central part of the flat part 1ia in which the groove is formed to form the recess 11b, the recess 11b has the same depth and shape, extends on a common straight line, and can be connected to the recess 1 from opposite sides of the recess 11a. ．． 1 Base member 1 having two V erasers 11c and lid leading to a
form 1.

In the next step, Vil1c, li of the base member 11
Install optical fiber 16.17 in d, and erase this 11c
, and fix it with a fixing agent 21 such as low melting point glass while pressing it against the inner surface of the lid.

In the next step, the optical amplifying chip 14 having an optical coupling end face on its outer periphery is installed so that its optical coupling end faces 14a, 14b are optically connected to the optical fibers 16, 17. This installation consists of optical fibers 16, 17 and optical amplification chip 1.
The optical amplifying chip 14 is fixed to the heat sink 12 while maintaining the optimal coupling state by moving the optical amplifying chip 14 in the x, y axis direction and the θ, ψ angle axis direction so as to optically optimally couple the optical amplifying chip 14 with the heat sink 12. will be carried out.

As described above, in this embodiment, the optical fiber 1
Since the optical fibers 6 and 17 are placed and fixed in the building and the lid, the optical axes of the pair of opposing optical fibers 16 and 17 can be aligned without adjusting the angle or position. Compared to the conventional example shown in FIG.
The optical connection with the device can be made simple and highly accurate.

Incidentally, in the above embodiment, a case has been described in which the configuration is made up of a V4 unit processed as one body, a pair of optical fibers fixed thereto, and an optical amplification chip installed between them. There is no limitation, and it may be a vortex such as a ditch, a half-harmonious arrangement, or a semi-harmonious arrangement.

Furthermore, in the above embodiments, the V-groove is directly formed on the block body, but the present invention is not limited thereto. may be configured.

Further, in the above embodiment, a case has been described in which an optical fiber and a power/light amplification chip installed between them are optically connected, but the present invention is not limited to this, and OBIC is used as an optical element. (Opto-elect
It is also applicable to devices using other elements such as ronics IC), external modulators, and optical switches.

Furthermore, in the above embodiment, a case was explained in which a pair of hot water and a pair of optical fibers were used, but the present invention is not limited to this, and can also be applied to a case in which two or more pairs of grooves and optical swivers are used. can.

〔Effect of the invention〕

As explained above, according to the present invention, four parts are formed on a predetermined surface of the base member, have the same depth and shape, extend on a common straight line, and communicate with the recess from opposite sides of the recess. one or more pairs of grooves. Therefore, by placing the optical fibers on the paired fibers, the central axes of the paired optical fibers can be aligned.

Therefore, it has the effect that the optical connection between the optical fiber and the optical coupling end face of the optical amplification chip placed at the center of the optical fiber pair can be made easily and with high precision.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are schematic plan views showing an optical amplification module which is an embodiment of an optical coupler according to the present invention, and its I.
2 is a schematic longitudinal sectional view showing an example of a conventional optical amplification module. 11...Base member, lla...Plane part, 1lb-
・Concavity, 1 1 c, 1 1 d, V clear, ・
...14... Optical amplification chip, 16.17... Optical fibers 16a, 17a... Ends. (X Kichi Ii+15 'afE++4 ma) Patent applicant Oki Electric Industry Co., Ltd. Agent Patent attorney Maeda Minoruki 1-2→t is I-1 machine i) to Figure 2

Claims (1)

[Scope of Claims] A base member; a recess formed on a predetermined surface of the base member; one or more pairs of grooves formed from the opposite side of the recess to the recess; one or more pairs of optical fibers installed in the groove so that their ends face each other; and an optical coupling end surface on the outer periphery. and an optical element provided in the recess so that the optical fiber is optically connected to the optical coupling end face.