JPS61189508A - Optical star coupler - Google Patents

Abstract

PURPOSE:To obtain a uniform output by arranging input-side and output-side optical fibers in different directions and connecting them to a light guide. CONSTITUTION:Output light incident from an input-side optical fiber 9 becomes output light having a spread in a dielectric light guide during operation and the light is reflected repeatedly by respective end surfaces and upper and lower surfaces of the dielectric light guide 17 to enter output-side optical fibers 10-16 and 10'-16' respectively. Output light having no spread is reflected by end surfaces 22-25 of the dielectric light guide 17 and then reflected repeatedly by respective end surfaces 22-25 and upper and lower surface 18 and 19 of the light guide 17 to enter the output-side optical fibers 10-16 and 10'-16'. Consequently, the output light is distributed uniformly to the respective output- side optical fibers 10-16 and 10'-16'.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an optical star coupler used in an optical seven-point communication system, etc., and particularly relates to an optical star coupler used in an optical seven-point communication system, etc. This invention relates to an optical star coupler for distributed transmission.

[Background technology and its problems]

In recent years, optical distribution circuits for distributing and transmitting optical signals transmitted through optical fibers to two or more saturation system terminals, etc., and for monitoring optical signals being transmitted, have been developed.
It is one of the indispensable devices, and the light star power is used.

This type of optical star coupler has conventionally been constructed as shown in Figure 4 ((b), where (&) is a perspective view and (b) shows the propagation process of light waves in the dielectric guided wave path. .

In the figure, 1 to 5 are input side optical fibers, 1' to 5' are output side optical fibers, 6 is a dielectric optical waveguide, and 7 is a dielectric guided waveguide 6 to which input side optical fibers 1 to 5 are connected. The end face 8 is an end face where the output side optical fibers 1' to 5' are connected to the dielectric optical waveguide 6. Then, the input side optical fiber 1~
5 and output side optical fibers 1' to 5' are bonded to opposite end surfaces 7 and 8 of the dielectric optical waveguide 6, respectively. That is, in this conventional example, the input side optical fibers 1 to 5 and the output side optical fibers 1' to 5' are arranged in the same direction.

Incidentally, as shown in FIG. 4(b), the output light from any optical fiber among the input side optical fibers 1 to 5 expands in beam diameter within the dielectric optical waveguide 6 and reaches the end face of the dielectric optical waveguide 6. The light is reflected repeatedly and mixed within the dielectric optical waveguide 6.

Output light that does not spread within the dielectric optical waveguide 6 is not reflected at the end face of the dielectric optical waveguide 6 and is directly transmitted to the output side optical fiber 1.
'~5', each output side light 7 eyes · 1
1, N evenly distributed between '~5'.

[Purpose of the invention]

An object of the present invention is to provide an optical star coupler that eliminates the above-mentioned conventional problems by preventing output light that does not spread within an optical waveguide from directly entering an output optical fiber.

[Summary of the Invention] This invention provides an optical star coupler consisting of one or more input side optical fibers, a plurality of output side optical fibers, and an optical waveguide. The optical fibers are optical star couplers arranged in different directions and connected to the optical waveguide.

[Embodiments of the invention]

The optical star coupler of this invention is shown in FIG. 1(a) t(b)
(a) is a perspective view, and (b) shows the propagation process of light waves within the dielectric optical waveguide.

That is, a single input side optical fiber 9 and a plurality of output side optical fibers 10 are connected to the end face 20, 21 of the dielectric optical waveguide 17 made of a high refractive index material formed from a polygonal glass rod.
~16.10'~16' are connected. In this case, the thickness of the dielectric optical waveguide 12 is the same as that of the optical fiber 9.
It is set to be equal to the cladding diameter of 10 to 16.10' to 16', for example, 125 μm. Furthermore, the input side optical fiber 9 and the output side optical fiber 10~16.10'~
16' are arranged in different directions, for example, orthogonal directions, and are connected to the end face of the dielectric optical waveguide 12.
The input side optical fiber 9 and the output side optical fibers 10 to 16
．． an end surface 22 to which 10' to 16' are not connected;
23°2'4.25 and the upper and lower surfaces 18.19 are provided with a vapor-deposited aluminum film to form reflective surfaces.

During operation, the output light incident from the input side optical fiber 9 becomes output light with a spread within the dielectric optical waveguide 17.
The light is repeatedly reflected at each end surface and upper and lower surfaces of the dielectric optical waveguide 17, and is incident on each of the output side optical fibers 10-16 and 10'-16'. In addition, the output light without spread is reflected at the end faces 22 and 23 of the dielectric optical waveguide 17, and then reflected at the end faces 22 and 23 of the dielectric optical waveguide 17, 24',
25 and the upper and lower surfaces 18, 19, and is incident on each of the output side optical fibers 10 to I6.10' to 16'. By performing the above process, the output side light] - IPA1
1: Output light is distributed evenly to each of 0 to 16.10' to 16'.

[Modified example of the invention]

FIGS. 2 and 3 show a modification of the present invention, which provides the same effects as the above embodiment.

First, in FIG. 2, a substantially hexagonal columnar recess 29 is provided in a dielectric block 28, and the bottom and each side surface of the recess 29 are formed as reflective surfaces. Further, the dielectric block 28 has a groove 3.
2.27 are formed in different directions, for example, orthogonal directions, and one input side optical fiber 30 is formed in one groove 32.
are arranged, and a plurality of output side optical fibers 31, 31' are arranged in the other groove 27. The recess 29 is filled with a resin having a higher refractive index than the dielectric block 28, and a reflective film 37 is formed on one surface of the dielectric block 26, which has approximately the same refractive index as the dielectric block 28. , is fixed by covering it from above.

The embodiments and modifications described above are optical star couplers that are characterized by equally distributing output light from a certain optical fiber to a plurality of other optical fibers, but the input side of the embodiments and modifications described above are Even if a plurality of optical fibers are used, if the dimensions of the dielectric optical waveguide are appropriately selected, the output side optical fibers will be evenly distributed.

An example of this is shown in FIGS. 3(a) and 3(b), where (a) is a perspective view, and FIG. 3(a) shows the propagation process of light waves in the dielectric optical waveguide. That is, a plurality of input side optical fibers 3
5 is connected in a different direction to the output side optical fibers j 4 and J 4', for example, in a direction perpendicular to the output side optical fibers, and the same effect as in the above embodiment can be obtained. In the figure, 33 is a dielectric optical waveguide.

〔Effect of the invention〕

According to this invention, the output light without spreading within the optical waveguide 7 is directly transmitted to the output side optical fibers 10 to 16, 10' to 1.
6', the structure is simple and compact, and uniform output can be easily obtained.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) show an optical star coupler according to an embodiment of the present invention, where (a) is a perspective view, and (b) is a plan view showing the propagation process of light waves in the dielectric guided wave path. , FIG. 2 is a perspective view showing an optical star coupler according to a modification of the present invention,
FIG. 3(b) shows an optical star coupler according to another modification of the present invention, (a) is a perspective view, and (b) is a plane view showing the propagation process of light waves in the dielectric optical waveguide. Figures 4(a) and 4(b) show conventional optical star couplers, and (
FIG. 3A is a perspective view, and FIG. 3B is a plan view showing the propagation process of light waves in the dielectric optical waveguide. . 9...Input side optical fiber, 10~16.10'~15
'... Output side optical fiber, 17-... Dielectric optical waveguide. Applicant's representative Patent attorney Takeshi Suzue Industry Figure 1 (a) Figure 2 Figure 3 (a) Figure 4 (a) (b)

Claims (2)

[Claims] (1) In an optical star coupler consisting of one or more input optical fibers, multiple output optical fibers, and an optical waveguide, the input optical fiber and the output optical fiber are arranged in different directions. An optical star coupler characterized in that the optical star coupler is connected to the optical waveguide. (2) The optical star coupler according to claim 1, wherein the portion of the optical waveguide that is not connected to the optical fiber is formed as a reflective mirror surface.