JPH0219811A - Array type light receiver - Google Patents

Abstract

PURPOSE:To reduce the leaking amount of the light emitted from the optical fiber array of the title photodetector to an adjacent photodetector so that crosstalks between photodetectors can be reduced by constituting the photodetectors while using a base plate which can incline the area of the photodetectors other than the light receiving area. CONSTITUTION:The title receiver has a structure in which a ribbon fiber 5 which is plural optical fiber arrays held by an optical fiber holding plate 4 and plural photodiode (PD) arrays 7 fixed to a PD array base plate 6 are faced one to one and optically coupled to each other. Moreover, the optical fiber array holding plate 4 and a fiber interval adjusting holder 8 are placed on a table 10 and the table 10 is placed on the PD array base plate 6. When the table 10 which shields the part other than the light receiving surface of the PD arrays 7 is used in such way, reflected light rays from the end face 12 of the ribbon fiber 5 go to the PD arrays 7 only and crosstalks between the PD arrays can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photoreceiver, and particularly to an array type photoreceiver used in an optical parallel reception module used for an interface between computer terminals or between devices.

[Conventional technology]

As computers are rapidly becoming smaller and more sophisticated due to VLSI (Very Large Scale Integrated Circuits), the performance of interfaces between devices, which determine the performance of computer systems, are also becoming smaller and higher performance (increasing transmission distance). , higher speed, and improved electromagnetic noise tolerance) are strongly required. especially,
Optical fiber transmission, which is resistant to electromagnetic noise, is expected to increase speed and improve transmission distance, and is therefore being developed for use as an interface between devices. A DC-coupled, asynchronous parallel transmission interface is usually used as an interface between devices, and optical parallel transmission modules that perform transmission/reception are actively being researched.

For example, the optical parallel receiving module shown in Japanese Patent Application Laid-Open No. 61-132912 (see FIG. 3) has a ribbon fiber 2 held in a fiber holder 1 directly coupled to a monolithic photodetector array 3, and The light is made to enter from the back surface of the light receiving element so that the fiber tip and the electrical wiring of the light receiving element do not collide, and the electrical wiring is connected to an external terminal from the opposite surface.

[Problem to be solved by the invention]

However, in the conventional photodetector array module, the distance between each photodetector of the monolithic photodetector array 3 tends to be set quite small (in the conventional example, 25
0 μm), there was a problem in that the light emitted from the ribbon fiber 2 leaked to the adjacent light receiving element, resulting in increased crosstalk between the light receiving elements.

The purpose of the present invention was made in view of the above-mentioned problems, and
An object of the present invention is to provide an array type light receiver that can reduce crosstalk between light receiving elements.

[Means to solve the problem]

The array type photoreceiver of the present invention has a structure in which an optical fiber array and a photodiode array (hereinafter referred to as a PD array) face each other one-to-one and are directly optically coupled.
A base plate formed to cover all areas other than the D array light-receiving surface is inserted between the optical fiber array holding plate and the PD array substrate.

[Effect]

In this way, in the array type light receiver of the present invention, since the base plate can block light outside the light receiving area, crosstalk between the light receiving elements can be reduced.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is an assembled perspective view showing one embodiment of an array type light receiver according to the present invention, and FIG. 2 is an exploded perspective view of the same array type light receiver. This array type photoreceiver consists of ribbon fibers 5, which are a plurality of optical fiber arrays held on an optical fiber array holding plate 4, and a plurality of optical fibers fixed on a PD array substrate 6.
It has a structure in which the D array 7 faces one-to-one and is directly optically coupled. The ribbon fiber 5 is fixed to a fiber array spacing adjustment holder 8, and the tip of the ribbon fiber 5 protrudes from the holder 8 and is detachably held within the holding plate 4. In addition,
A cover glass 9 is attached to the bottom of the optical fiber array holding plate 4.
is fixed. In addition, the ribbon fiber 5 has, for example, all 12 cores, core spacing = 250 μm, 1 core diameter = 62.5 μm.
The m1 cladding diameter is 125 μm.

The optical fiber array holding plate 4 and the fiber array spacing adjustment holder 8 are placed on a base plate 10, and this base plate 10 is further placed on the PD array substrate 6. . At one end of this base plate 10, P
Grooves 10a are formed to cover all areas other than the light-receiving surfaces of the D array 7, and are provided at the same intervals as the light-receiving surfaces of the PD array 7. When the present array type light receiver is assembled as shown in FIG. 1, the base plate 10 is inserted between the optical fiber array holding plate 4 and the PD array substrate 6. Note that electrical terminals 11 are electrically connected to the PD array 7, respectively.

In this embodiment, the fiber array spacing adjustment holder 8 adjusts the core spacing of the ribbon fibers 5 to 250, for example.
It is expanded from μm to 650 μm.

This ribbon fiber 5 has a thickness of 650 μm using Guisingz.
The fibers are arranged in periodically machined grooves 8a, and the fiber end face 12 (see FIG. 2) is cut at an angle of 45°.

Therefore, the light from the ribbon fiber 5 is totally reflected by the fiber end face 12 and enters the light receiving surface of the PD array 7.

The PD array 7 is also arranged on the PD array substrate 6 at the same period as the ribbon fiber 5, and the receiving diameter is, for example, 10 mm.
It was set to 0 μm. Further, the base plate 10 has a thickness of, for example, 0.5 mm.
For example, grooves 10a having a width of 125 μm are provided at one end with a pitch of 650 μm. The grooves 10a are positioned in advance so as to face the light-receiving surface of the PD array 7, and then the ribbon fibers 5
Adjustment is made so that the PD array 7 faces the PD array 7 on a one-to-one basis.

In this way, by using the base plate 10 that blocks light from areas other than the light-receiving surface of the PD array 7, the function of adjusting the distance between the light-receiving surface of the PD array 7 and the end surface 12 of the ribbon fiber 5 can be achieved. In addition, the reflected light from the end face 12 of the ribbon fiber 5 did not leak beyond the opposing PD array 7, and a loss talk between the PD arrays of 50 dB or more was achieved.

Furthermore, in this embodiment, the end face 1 of the ribbon fiber 5
2 has the advantage that even if the surface accuracy is poor and diffuse reflection occurs, this crosstalk can be maintained, and predetermined characteristics can be obtained even if the end face processing accuracy is slightly degraded. Note that in this embodiment, the interval between the PD arrays 7 is 650 μm.
However, it goes without saying that it is effective even with dimensions other than this. In addition, a monolithic PD with a period of 250 μm
If an array is used, the fiber array spacing adjustment holder 8
Ribbon fibers 5 can be directly arranged on the optical fiber array holding plate 4 without using. On the other hand, as for the coupling method, in addition to the lateral coupling method in which the end face of the fiber array is polished at an angle of 45°, a configuration in which the end face of the fiber array is vertically polished and the fiber array and the PD array are arranged linearly can also be considered. In addition, in the embodiment described above, the base plate 10 has a PD.
Although the grooves 10a are provided at the same spacing as the spacing between the light receiving surfaces of the array 7, the structure is not limited to this, and a structure may be provided in which holes are provided instead of the grooves 10a.

〔Effect of the invention〕

As explained above, according to the array-type light receiver according to the present invention, the structure uses a base plate that can be moved diagonally outside the light-receiving area, so that the light emitted from the optical fiber array is transmitted to the neighboring light-receiving area. There is no leakage to the elements, and this has the effect of significantly reducing crosstalk between the light receiving elements compared to the prior art.

[Brief explanation of drawings]

FIG. 1 is an assembled perspective view showing an embodiment of an array type photoreceiver according to the present invention, FIG. 2 is an exploded perspective view of the same array type photoreceiver, and FIG. 3 is a perspective view showing a conventional receiving element array module. It is. 4... Optical fiber array holding plate, 5...
・Ribbon fiber, 6...PD array board, 7
...PD array, 8...Fiber array interval adjustment holder, 10.
...base plate, 10a...groove. Applicant NEC Co., Ltd. Agent Patent Attorney Yamauchi Umesho Figure 1 Figure 2

Claims (1)

[Claims] In an array type receiver in which an optical fiber array and a photodiode array face each other one-to-one and are directly optically coupled, a base plate formed to cover everything except the light-receiving surface of the photodiode array is connected to the optical fiber array. An array type photoreceiver characterized by being inserted between a holding plate and a photodiode array substrate.