JPS58196504A - Optical branching device - Google Patents

Abstract

PURPOSE:To obtain an optical branching device which has good mass productivity and small loss of light and variation thereof and can vary a branching ratio by constituting the branching device of an optical fiber assemblage, forming each exit end face into a circular shape, integrating incident end faces to one body for each of the optical fiber assemblages that make branch passages for each light and assembling the same to an elliptial shape as a whole. CONSTITUTION:An optical branching device 10 in an optical fiber assemblage wherein plural pieces of optical fibers 11 of fine glass are bundled, that is, one end of the bundled optical fibers is used as an incident end face 12 for light and the other end is branched to two as branch passages 14 and 15. The outside shape of the bundled optical fibers for exit end faces 16 and 17 of light is made into the circular shape of the same diameter as the diameter of optical fibers 1, 2 and 3 for transmission and reception. The bundled optical fibers for the face 12 are bundled to the elliptical shape having the width equal to the diameter of the circular shape of the exit end face for light and the semicircular shape equal to the top and bottom ends of said end face. The bundled optical fibers constituting the paths 14 and 15 are distinctly separated at the boundary of a line 18.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical branching device for branching transmitted optical signals in optical fiber transmission using an optical fiber with a relatively large core diameter as a transmission line. .

In recent years, optical fiber transmission has been put into practical use, and is being applied not only to general communications but also to relatively simple signal transmission in the consumer and industrial equipment fields. Optical fibers with relatively large core diameters, such as plastic optical fibers, are used for simple optical fiber transmission, and one optical component suitable for such optical fibers is an optical splitter for branching optical signals. is considered useful.

The conventional optical splitter as described above will be explained below with reference to the drawings.

FIG. 1 shows the configuration of a conventional optical splitter. 1st
In the figure, 1 is a transmitting optical fiber, 2 and 3 are receiving optical fibers, and the optical fibers 1, 2, and 3 are plastic optical fibers with large core diameters. 4 is an optical splitter, one tip of two plastic optical fibers 5 and 6 is gradually polished and bonded to each other using adhesive 9 at position 8, and at the position of the light incident end at 7. The outer diameter is the same as the core diameter of the transmission optical fiber 1.

The operation of the optical splitter configured as described above will be described below. First, light emitted from the transmission optical fiber 1 enters the input end 7 of the optical splitter 4. The light incident on the optical splitter 4 passes through the adhesive surface 8, gradually branches into two optical fibers 6 and 6, propagates, and branches into receiving optical fibers 2 and 3, respectively.

However, in the above configuration, the optical splitter 4 polishes the optical fibers 6 and 6 and adheres them to each other, which not only makes it difficult to mass-produce, but also reduces the amount of light emitted from the center of the transmitting optical fiber 1. However, since the light passes through the adhesive 9, there is a drawback that there is a large loss of light. Further, in such a configuration, the branching ratio for branching the light emitted from the transmitting optical fiber 1 to each receiving optical fiber 2 and 3 is determined by the polishing ratio at the position 8 of the optical fibers 6 and 6, and cannot be changed. However, it had drawbacks such as lack of versatility as the characteristics varied depending on the amount of polishing.

In view of the above-mentioned drawbacks, the present invention provides an optical branching device that is suitable for simple optical fiber transmission used in the fields of consumer and industrial equipment, has good mass productivity, has small optical loss and its variation, and can further vary the branching ratio. It is something.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows the configuration of an optical splitter in the first embodiment of the present invention. In Figure 2, 1 is a transmitting optical fiber, 2 and 3 are receiving optical fibers, and optical fibers 1 and 2 are
and 3 are plastic optical fibers with a large core diameter. Reference numeral 1o designates an optical branching device constructed by bundling a large number of thin glass optical fibers 11; 12, a light input end face; 13, a light input path; 14 and 16, branch paths; and 16 and 17, light output end faces. The optical splitter 1o of this embodiment has a thin beam.
An optical fiber assembly in which a plurality of glass optical fibers 11 are bundled, that is, one end of the bundle optical fiber is used as the light incident end face 12, and the other end is branched into two, and a branch path 14 and 16 is formed.
That is. The light output end faces 16 and 17 have the outer shape of the bundle optical fibers as transmitting and receiving optical fibers 1,
The bundle optical fibers are formed into a circular shape having the same diameter as 2 and 3, and the light incident end face 12 has a width equal to the circular diameter of the light exit end face, and the bundle optical fibers are bundled into an oval shape with semicircular upper and lower ends. Further, at the light incident end surface 12, the bundle optical fibers constituting the branch paths 14 and 16 are clearly separated at the boundary indicated by the line 18 in the figure, and the optical fiber groups 19 and 2o in the center near the boundary 18 are Output end faces 16 and 1 respectively
The optical fibers are arranged to correspond to groups of optical fibers at positions 21 and 22 near the center of 7.

The operation of the optical splitter 10 configured as described above will be described below.

First, the light emitted from the transmission optical fiber 1 is transmitted to the input end face 1.
It enters the bundle optical fiber 11 corresponding to the plane where the two transmission optical fibers 1 are located, and enters each branch path 14,15. At this time, as shown in the explanatory diagram of the coupling surface between the input end surface 12 and the transmitting optical fiber 1 in FIG. 3, the transmitting optical fiber 1 shown in FIG.
is located at the center of the entrance end surface 12, the entrance end surface 12
Approximately 50% of the incident light is emitted from each of the output end faces 16 and 17, so the branching ratio is 1:1.

Next, as shown in Figure 3, the transmitting optical fiber 1 is connected to the input end face 1.
2, the bundle optical fibers constituting the input end surface 12
Since the branching path differs depending on the position of the boundary 18, the branching ratio also changes depending on the degree of positional deviation between the transmitting optical fiber 1 and the input end face 12. Furthermore, the light incident on the central optical fiber group 19 and 2o near the boundary 18 of the input end face 12 is transmitted to each output end 1
Since the light is emitted from the positions 21 and 22 near the center of the transmitting optical fibers 2 and 17, even if there is a positional shift when coupling the transmitting optical fiber 1 and the input end face 12, each receiving optical fiber 2 and 3
Light is concentrated and incident on the center.

As described above, according to this embodiment, the optical splitter 1o is constructed by an optical fiber assembly made by bundling a plurality of thin optical fibers 11, so mass production is easier than in the conventional example, which requires polishing and bonding. good. Furthermore, by arranging each of the thin optical fibers 11 as shown in the embodiment shown in FIG. 2, the light passing through the center of the transmitting optical fiber 1 is effectively used, so the loss of light is small. By changing the coupling position between the input end face 12 and the transmitting optical fiber 1, the light branching ratio can be changed by 1.

A second embodiment of the present invention will now be described with reference to the drawings.

FIG. 4 is an explanatory diagram showing a second embodiment of the present invention. In the figure, 1 is a transmitting optical fiber, 10 is an optical splitter constituted by a bundle optical fiber made by bundling a large number of thin glass optical fibers 11, 23, 24 and 25 are optical branching paths, and 26, 27 and 28 are thin A light output end face with a circular outer shape of a bundle optical fiber in which the optical fibers 11 are bundled;
Reference numeral 12 denotes a light input end face, which has an outer shape in which thin optical fibers 11 are bundled into an oval shape whose width is the diameter of the output end face. 13 is a light incident path. The difference from the configuration shown in FIG. 2 is that three light branching paths are provided, and the positions of the boundaries 29 and 3o shown in the same figure on the light incident end surface 12 are such that the bundled light beams forming each of the branching paths 23, 24 and 26 are different from the configuration shown in FIG. Along with separating the fibers,
Groups of optical fibers 31 near each boundary location 29 and 30.
Points 32, 33 and 34 are arranged to correspond to the optical fiber group near the center of the output end face 26, 27 and 28, respectively.

The operation of the optical splitter configured as described above will be described below.

The basic configuration of the optical splitter is the same as the embodiment shown in FIG. 2, but the way the light is split is different. When the transmitting optical fiber 1 is coupled at the center of the ellipse of the light incident end face 12, most of the light is emitted from the central branch path 24, and less light is emitted from the branch paths 23 and 25. Next, the transmission optical fiber 1 is connected to the input end face 1 at a position sandwiching the separation boundary 29, for example.
2, the light is branched and emitted from branch paths 23 and 24, but not emitted from branch path 25.
1 or more, by providing two branch paths 23, 24 and 25 for one input path 13, the second
In addition to the effects of the embodiment shown in the figure, depending on the coupling position of the transmitting optical fiber 1 and the input end 12 of the optical splitter 100, light may be emitted from one of the output end faces 26 and 28 of the two branch paths. Since it can be prevented from emitting light, it can function as a light splitter and a light changeover switch.

In the first and second embodiments, the thin optical fiber 11 is made of glass, but the thin optical fiber 11 may be made of plastic.

Further, in the second embodiment, three branching paths were used, but it goes without saying that any number of branching paths may be used.

Further, thin optical fibers 11 constituting the optical fiber assembly
The collective arrangement of the optical fibers 11 may be a quadrilateral arrangement, a hexagonal arrangement, or a circular arrangement as shown in FIG. It may be transformed into

Hereinafter, as shown in L, the present invention constitutes an optical branching device by an optical fiber assembly, each output end face is circular, and the input end face is integrally split for each optical fiber assembly that forms a branch path for each party, and the whole They gather in an oval shape. Furthermore, the following effects can be obtained by arranging the optical fiber assemblies so that the light that enters near the boundary between adjacent optical fiber assemblies at the input end exits from around the center of each output end face. .

(1) Since the light transmitted through the center of the optical fiber is used effectively, the loss of light is small.

(2) Since an optical fiber assembly in which a plurality of thin optical fibers are bundled is used, the variation in characteristics is smaller than in the conventional example, and mass productivity is good.

(3) Any branching ratio can be obtained by changing the position of the optical fiber coupled to the input end face.
(4) In a configuration having three or more branch paths, it is possible to prevent light from being emitted from any branch path, and it functions as an optical switch.

[Brief explanation of drawings]

FIG. 1 is a plan view of a conventional optical splitter, FIG. 2 is a plan view and cross-sectional view of an optical splitter according to an embodiment of the present invention, and FIG. 3 is an explanatory diagram of the incident coupling surface in FIG. FIG. 4 is a perspective view of an optical splitter in another embodiment of the present invention, and FIG. 5 is a diagram showing an example of arrangement of thin optical fibers. 1... Input optical fiber, 2, 3... Output optical fiber, 1o... Optical splitter, 11...
... Thin optical fiber, 12 ... Light incident end face, 13 ... Input path, 14 , 16 , 23 ,
24, 25... Branch road, 16°17, 26
, 27, 28... Light output end face, 18°2
9.30---Boundary of optical fiber assembly, 19°20 21 22 31 32 33
34... Optical fiber group. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 @ Figure 3 (al (b > 4) II Figure 5 (a) (bl (C)
(tPino N // // n

Claims (2)

[Claims] (1) A plurality of light branching paths consisting of a fiber aggregate whose end face has an approximately circular outer shape, and the other ends of the plurality of likely branching paths are assembled, and the end face has an outer shape of an AfJ branch. an input path consisting of a collection of optical fibers arranged in an oval shape whose shortest diameter passing through the center is equal to the diameter of the end surface of the input path, and the end surface Q-J of this input path, The optical fibers constituting the branch path are assembled into one block at the east combination f + t, and the round fibers are arranged so that light incident from any number of companies at the boundary between the adjacent blocks exits near the center point 1 of the end face of the plurality of branch paths. Arrange the aggregate+jll. An optical splitter characterized by: (2) Providing an optical fiber that allows light to enter the light input path, and moving the end face of the light input path and the round fiber in a direction perpendicular to the direction of travel of the light [not coupled to the IT function] An optical branching device according to claim 1, characterized in that: