JPH08278424A - Optical splitter - Google Patents

Abstract

PURPOSE: To save space by integrally executing a non-reflection treatment of the unused terminals of an optical splitter composed of 2x2 optical fiber couplers. CONSTITUTION: Respective optical fibers 40 are connected to the non-used terminals 112, 211,...331, 342 of the respective optical fiber couplers 11, 21,...33, 34. Their front ends are lined up on a substrate 68 having V-grooves 64, etc., and are fixed by adhesive to form an optical fiber group 42. A slit 72 (inclining at >=8 deg. with a plane 50 perpendicular to the optical fibers) which crosses all the optical fibers of the group 42 and bites into the substrate 68 is formed and total reflection films 60 are inserted therein and are fixed by adhesives. As a result, the simultaneous non-reflection treatment of all the unused terminals is possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical splitter, and more particularly to a 1x optical fiber coupler having a 2x2 optical fiber coupler.
The present invention relates to a 2n (n is a power of 2 value such as 2, 4, 8 and-) splitter.

[0002]

2. Description of the Related Art An example of a 1 × 8 optical splitter composed of a 2 × 2 optical fiber coupler is schematically shown in FIG. 1
Reference numeral 1 denotes a 2 × 2 optical fiber coupler, which is, for example, a fusion taper type, and has four terminals 111, 112, 113, 114. Optical couplers 21 and 22 are connected to the output side terminals 113 and 114, respectively, and these output side terminals 21 and 21 are connected.
Optical couplers 31 to 34 are connected to 3, 214 and the like to configure the optical splitter 10. 111 is an input terminal and 313, 314, --- 343, 344 are output terminals.

Each of the above optical couplers 11, 12, 22, ---
The terminals 111, 211, 212, 311, such as −, etc. are subjected to antireflection processing because there is no partner to connect to them.

The non-reflective processing includes, for example, the following methods. Connect coreless fiber (see Proceedings of the 1994 IEICE Spring Conference, C-378). When an optical fiber without a core is connected, the light incident on it is immediately leaked. Since the light does not reach the reflection point at the end of the coreless fiber, a reflectionless termination is realized. Using a non-reflective terminal connector (Japanese Patent Laid-Open No. 5-1001)
28, etc.). The unused terminals 112 and the like are obliquely polished at 8 degrees.

[0005]

However, each of the above processing methods has the following problems. In the case of the coreless fiber of No. 3, since fusion is required, it is not suitable for space saving. Also in the case of the non-reflective termination connector, there is a problem of space for arranging the connector. In the case of oblique polishing, if there is condensation or foreign matter on the polished surface, the refractive index changes and reflected light is generated.

[0006]

As illustrated in principle in FIG. 2, the unused terminals 112, 211, --331, 342 of the respective optical fiber couplers 11, 21, --- 33, 34 are connected. ,
The optical fibers 40 are connected to each other, and the optical fiber groups 42 are formed by aligning the tip portions of the optical fibers 40 so that they are in contact with or close to each other. The optical fiber group 42 is cut along one flat surface 52 that is inclined with respect to the optical fiber group 42 ((b) in the same figure). 60 is adhered ((c) in the figure).

FIG. 3 shows various methods for forming the optical fiber group 42 by aligning the tip portions of the optical fibers 40 so that they are in contact with or close to each other. As shown in (a) and (b) of the figure, only the optical fibers 40 are aligned, and the number of cores is increased by an adhesive 62 or the like (using the technique of increasing the number of single-core optical fibers).

As shown in FIGS. 3 (c) and 3 (d), they are arranged on a substrate 68 having V-grooves 64, U-grooves 66, etc. and fixed by embedding with an optical adhesive. As shown in (e) and (f) of FIG.
Arrange in steps and fix with adhesive.

The plane 5 having an angle θ of 8 degrees or more with respect to a plane 50 perpendicular to the optical fibers forming the optical fiber group 42.
When the optical fiber group 42 is cut along the line 2, the end surfaces of the optical fibers are made to be mirror surfaces with a ceramic blade or the like.

When the optical fiber group 42 is formed using the substrate 68 as shown in FIGS. 3C to 3F, FIG.
As described above, by providing the slit 72, the optical fiber is cut at the same time. At that time, the slit 72 cuts off the optical fiber 40 and reaches about 1/3 to 1/2 of the thickness of the substrate 68.

In this way, the optical fiber from the groove may be removed or left as it is (FIG. 1 shows the case where it is not removed, and FIG. 4 shows the case where it is removed).

In the case of FIGS. 3A and 3B, the reflection film 60 is collectively attached to the end faces of all the optical fibers 40 of the cut optical fiber group 42.

As shown in FIGS. 3C to 3F, when the slit 68 is formed using the substrate 68, the reflective film 60 is inserted into the slit 72 and fixed with an adhesive.

[0014]

[Operation] A large number of non-reflective terminal treatments can be processed together. When the reflection film 60 is adhered to the end surface of the optical fiber 40,
Since there is no change in the refractive index due to dew condensation on the end face, no reflected light is generated.

[0015]

EXAMPLE A model is shown in FIG. In addition, B of the same figure (a)
The part is enlarged and shown in (b). Each optical fiber coupler 1
Unused terminals 112, 21 of 1, 21, --- 33, 34
Optical fiber 40 connected to 1, --- 331, 342
Were arranged on a substrate 68 having a V groove 64 and fixed with an optical adhesive to form an optical fiber group 42. The slit 72 that crosses the optical fiber 40 and bites into the substrate 68 is formed by using a ceramic blade and a grinding liquid containing an abrasive. θ was set to 45 °, for example.
The total reflection film 60 was inserted into the slit 72 and fixed with an optical adhesive (FIGS. 1B and 4) to complete the antireflection treatment.
The total reflection film is a total reflection film that reflects a communication wavelength light used in optical fiber communication to a certain extent, for example, near 100%, for example, by applying a reflection film on a glass substrate or a polyimide substrate by vapor deposition or the like. Shall be pointed out.

[0016]

EFFECTS OF THE INVENTION A large number of non-reflective termination processes can be collectively processed, and space saving and process saving can be achieved. Since the reflection film 60 is adhered to the end face of the optical fiber 40, there is no change in the refractive index due to condensation on the end face, and no reflected light is generated.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is a diagram illustrating the principle of the present invention.

FIG. 3 is an explanatory diagram of various means constituting the optical fiber group 42 in the present invention.

FIG. 4 is a perspective view of an optical fiber group 42 according to an embodiment of the present invention.

FIG. 5: 1x2 constructed by a 2x2 optical fiber coupler
FIG. 3 is a general explanatory diagram of an n (n is a power of 2 value such as 2, 4, 8, or the like) splitter.

[Explanation of symbols]

 10 Optical Splitter 11 Optical Coupler 21,22 Optical Coupler 31-34 Optical Coupler 112,211,-331,352 Unused Terminal 40 Optical Fiber 42 Optical Fiber Group 50,52 Plane 60 Reflective Film (Total Reflective Film) 62 Adhesion Agent 64 V groove 66 U groove 68 Substrate 70 Wide groove 72 Slit

Claims (1)

[Claims] 1. A 1x2n (n is a power of 2 such as 2, 4, 8, ---, etc.) constituted by a 2x2 optical fiber coupler.
In the splitter, an optical fiber is connected to an unused terminal of each optical fiber coupler, and tip portions of the optical fiber are aligned in contact with or in close proximity to each other to form an optical fiber group, which constitutes the optical fiber group. Along a plane inclined to the plane perpendicular to the optical fiber,
An optical splitter in which the optical fiber group is cut, and a reflection film is collectively attached to the end faces of all the optical fibers of the cut optical fiber group.