JPH07335915A - Light emitting/receiving element module - Google Patents

Abstract

PURPOSE:To obtain a light emitting/receiving module having simple structure requiring no ferrule in which the surface of a glass cover for a light emitting/ receiving element is protected against damage at the time of mounting/ demounting a fiber and a constant interval can be sustained easily between the surface of the cover glass and the forward end of the optical fiber. CONSTITUTION:In a light emitting/receiving element module for coupling a light emitting/receiving element with an optical fiber 51 not through a ferrule, a sheet-like space 14 is provided between the light emitting/receiving element 7 and the forward end part of the optical fiber 51 in the housing 1 of the module. The sheet-like space 14 is provided with an opening 15 on the side of the housing 1 and a translucent film 3 for spacer is disposed in the sheet-like space 14 in order to sustain a interval between the light emitting/receiving element 7 and the forward end part of the optical fiber 51.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting / receiving element module used for optical fiber communication.

[0002]

2. Description of the Related Art A module for coupling an optical fiber and a light emitting / receiving element used for optical communication is often required to have a precise alignment, which requires high processing accuracy and is costly. It is also desired that the optical fiber can be attached and detached.

In response to these demands, as an inexpensive light emitting and receiving element module, for example, in the "simple optical module" of Japanese Patent Application Laid-Open No. 2-90113, an optical fiber suppressing portion having a protrusion on the contact surface with the optical fiber is provided. The optical module according to the present invention is capable of attaching / detaching an optical fiber and is inexpensive. In addition, the present inventor also discloses, in Japanese Patent Application No. 5-287193, "Receiving and emitting element module", which has a simple structure and in which an optical fiber can be attached and detached.

[0004]

The above-mentioned "simple optical module" and "light emitting / receiving element module" are aimed at an inexpensive structure, and therefore do not have a structure using a ferrule. Therefore, since the optical fiber having "one" which is often generated at the time of cutting the fiber is inserted into the module each time it is attached and detached, this "one" directly hits the cover glass surface of the light emitting and receiving element. (See Figure 5).

As a result, the glass surface is damaged, and diffuse reflection occurs on this surface, leading to an increase in connection loss. In the worst case, the cover glass may be damaged.

Further, when the optical fiber is attached to or detached from the module, it is difficult to keep the distance between the cover glass surface of the light emitting and receiving element and the tip of the optical fiber constant.

According to the present invention, in a light emitting and receiving element module having a simple structure that does not require a ferrule, the cover glass surface of the light receiving and emitting element is not damaged when the fiber is attached or detached, and at that time, An object of the present invention is to provide a light emitting and receiving element module in which the distance between the cover glass surface of the light emitting element and the tip of the optical fiber can be easily kept constant.

[0008]

Therefore, according to the present invention, there is provided a light emitting and receiving element module for coupling a light receiving and emitting element and an optical fiber without a ferrule, and in the housing of the module, the light receiving and emitting element and the Provided is a light emitting and receiving element module which has a sheet-shaped space portion between the end portions of the optical fibers, and the sheet-shaped space portion has an opening at a side portion of the housing.

Further, a translucent film for spacers may be arranged in the sheet-like space to maintain a distance between the light emitting / receiving element and the tip of the optical fiber. Furthermore, a space portion communicating with the sheet-shaped space portion may be provided on a side surface on the opening side of the sheet-shaped space portion at a location where the strand of the optical fiber is inserted.

Therefore, in order to solve the above-mentioned problems, the present inventor first investigated the relation of the coupling loss when the distance between the optical fiber and the LED light emitting element in the Z-axis direction was changed. The result is shown in FIG. The NA of the optical fiber used at this time is 0.5, the core diameter is 200 μm, and the LED
Is LN-181LA manufactured by Matsushita Electric. In addition, this L
Regarding the directional characteristics of the ED, the half-value angle θ _{50 at} which the light intensity is 50% has a value of 10 degrees.

Generally, the insertion loss in an optical fiber connector is 1.5 to 2.5 dB or less in the case of, for example, a multi-component multi-mode fiber, as shown in JIS standard C 5962-1990. That is, it is considered that the coupling loss caused by the displacement in the Z-axis direction is within the practical range if it is about 1 dB or less. Therefore, from this result, the distance between the optical fiber and the light emitting element is 20
It has been found that practical optical coupling can be realized even if it is expanded to about 0 μm.

In other words, it can be derived that it is not always necessary to keep the tip of the optical fiber in contact with the light emitting element in order to obtain optical coupling in a practical range in such a module or connector.

One of the reasons why the coupling loss does not increase so much with respect to the deviation in the Z-axis direction is that the directional characteristics of the LED used are sharp (the half-value angle θ ₅₀ is small). For LEDs with a large half-value angle θ ₅₀ ,
It is considered that the coupling loss tends to increase.

Regarding the coupling loss with respect to the displacement of the light receiving element in the Z-axis direction, since the light receiving surface is large, it is said that the displacement in the Z-axis direction is insensitive.

Therefore, the housing of the module of the present invention has a sheet-like space portion between the light emitting / receiving element and the tip of the optical fiber, and the space portion has an opening at a side portion of the housing. A spacer film is arranged in the space. When inserting the optical fiber, press the tip of the optical fiber to the film to position and fix the optical fiber, or press the tip of the optical fiber to the spacer film to position and fix the optical fiber and then fix the film. By removing, the above-mentioned object was achieved. In addition, when connecting the light emitting and receiving element and the optical fiber through the spacer film,
It is essential that the spacer film is translucent.

In addition, in the housing of the module,
It is preferable to provide means for pressurizing and fixing the side surfaces of the fiber portion and the core portion of the optical fiber. Examples of means for fixing the pressure include a female screw portion and a bolt, a leaf spring, and the like.

[0017]

As described above, in a light emitting and receiving element module having a simple structure which does not require a ferrule and in which an optical fiber can be attached and detached, the cover glass surface of the light emitting and receiving element is damaged when the fiber is attached and detached. Disappears. In addition, the distance between the cover glass surface of the light emitting / receiving element and the tip of the optical fiber can be easily kept constant.

[0018]

【Example】

(Embodiment 1) An embodiment of the present invention will be described with reference to FIG. First, the housing 1 has a portion 11 for accommodating the light emitting / receiving element 7 at one end thereof, and the light emitting / receiving element 7 (for example, an LED or the like) is accommodated therein.

Next, the housing 1 is provided with a sheet-like space portion 14 having an opening at a side portion of the housing for disposing the spacer film, and the translucent spacer film 3 is disposed therein. It When the optical fiber is inserted and fixed, the tip end of the optical fiber hits the film 3 and therefore does not hit the cover glass of the light emitting / receiving element 7. Further, the film 3 can keep the distance between the tip of the optical fiber and the light emitting / receiving element constant. This translucent film is PE
It is preferably made of T, PVC, PC, nylon, acrylic or the like.

Subsequently, the housing 1 has an arrangement portion 12 which is a hole having an inner diameter for communicating with the light emitting / receiving element housing portion 11 and the sheet-like space portion 14 and into which the wire portion 51 of the optical fiber can be inserted. And, in this arrangement location 12,
As means for pressurizing the side surface of the fiber portion 51 of the optical fiber, it has a female screw portion, a bolt 21, and a pressing plate 22. The pressing plate 22 has a recess corresponding to the diameter of the strand. By applying pressure to the wire portion 51 of the optical fiber 5 arranged at the arrangement location 12 by this means,
The optical position of the optical fiber can be determined.

Further, the housing 1 has the above-mentioned arrangement portion 1
It has an arrangement place 13 which is a hole having an inner diameter into which the core portion 52 of the optical fiber can be inserted. The arrangement portion 13 has a female screw portion, a bolt 23, and a pressing plate 24. The pressing plate 24 has a recess corresponding to the diameter of the core wire portion. By this means, the optical fiber arranged at the arrangement location 13 can be mechanically fixed by pressing the core wire portion 52 of the optical fiber.

The secondary coating of the core portion 52 of the optical fiber is
It is desirable to be composed of a metal tube or the like in order to obtain mechanical strength. In this case, for example, the metal material can be selected from stainless steel, carbon steel, aluminum, copper, titanium, etc. depending on the environment of use and required specifications.
The light emitting / receiving element module is configured as described above.

The optical fiber used at this time is
It is desirable that it has excellent mechanical strength and a large core diameter. For example, it is an optical fiber whose opening angle is 0.35 or more, whose surface is coated with a resin composition having a Shore D hardness of 50 or more, and whose core diameter is 200 μm or more.

Specific examples thereof include a quartz fiber having a hard plastic clad and the optical fiber disclosed in the above-mentioned JP-A-2-153308. In this specific example, a hard coat multi-component optical fiber manufactured by Nippon Sheet Glass (trade name: EPF, model number: EI-200 / 230-20).
F5, (core / clad diameter = 200/220 μm, NA
= 0.5)) was used.

Since the film is often damaged when the optical fiber is attached or detached, it is preferable to replace the film each time the optical fiber is attached or detached.

(Example 2) In Example 1, the light emitting / receiving element and the optical fiber were connected through the translucent film.
In Example 2, the spacer film was first placed in the space, the optical fiber was inserted and fixed, and then the spacer film was removed to connect the light emitting / receiving element and the optical fiber. See FIG.

Further, on the side surface on the opening side of the sheet-like space portion at the location where the strand of the optical fiber is inserted,
It has a space portion 16 communicating with the sheet-like space portion. Therefore, when the spacer film is removed, even if the "three" 53 of the optical fiber bites into the film 3, the optical fiber can be bent and escaped, and the film can be easily removed. There is. An explanatory view of the situation in that case is shown in FIG.

The spacer film is made of PET, PVC,
It is preferably made of PC, nylon, acrylic or the like, but in the case of the second embodiment, it need not necessarily be translucent.

[0029]

As described above, the light emitting and receiving element module of the present invention can realize low-cost optical coupling, and even if the optical fiber is frequently attached and detached, the light receiving and emitting by "one" of the optical fiber is performed. The cover glass of the device is not damaged. In addition, the distance between the cover glass surface of the light emitting / receiving element and the tip of the optical fiber can be easily kept constant.

[Brief description of drawings]

FIG. 1 is a diagram showing a cross-sectional structure of a light emitting and receiving element module according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship of coupling loss when the distance between the optical fiber and the LED light emitting element in the Z-axis direction is changed.

FIG. 3 is a diagram showing a cross-sectional structure of a light emitting and receiving element module according to another embodiment of the present invention.

FIG. 4 is a diagram illustrating a state of removing a spacer film in the light emitting and receiving element module shown in FIG.

FIG. 5 is a schematic diagram for explaining “a piece” that occurs when the fiber is cut.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 housing 11 location for storing light emitting / receiving element 12 location for storing optical fiber strand 13 location for storing optical fiber core 14 sheet-like space 15 sheet-like space opening on side of housing 16 optical fiber Space to allow the escape 21,23 bolts 22,24 pressing plate 3 (translucent) spacer film 51 optical fiber strands 52 optical fiber cores 53 optical fiber "tsu" 7 light emitting and receiving elements

Claims (3)

[Claims] 1. A light emitting / receiving element module for coupling a light emitting / receiving element and an optical fiber without a ferrule, wherein a sheet is provided in a housing of the module between the light emitting / receiving element and a tip portion of the optical fiber. A light receiving and emitting element module, characterized in that the sheet-like space portion has an opening at a side portion of the housing. 2. The light receiving and emitting element module according to claim 1, wherein a light transmitting and receiving film for spacers is arranged in the sheet-shaped space to keep a distance between the light receiving and emitting element and the tip of the optical fiber. Light emitting device module. 3. The light emitting and receiving element module according to claim 1, wherein a side surface on the opening side of the sheet-shaped space portion at a location where the strand of the optical fiber is inserted communicates with the sheet-shaped space portion. A light emitting and receiving element module having a space portion to be formed.