JPH0563655A - Branching changeover device for optical fiber cable - Google Patents

Abstract

PURPOSE:To realize a branching changeover device for an optical fiber cable in which optional automatic arrangement is attained among three branches without converting an optical signal into an electric signal. CONSTITUTION:The device is provided with an optical fiber cable use branch region comprising optical fiber cables 40 branched in three directions and installed independently connected directly respectively from a 1st direction to a 2nd direction, from the 2nd direction to a 3rd direction and from the 3rd direction to the 1st direction, and optical branch coupling means 51, 52, 53 having an optical branch function and an optical coupling function are equipped with a connection part of each optical fiber cable in the optical fiber cable use branch region and the adjacent optical branch coupling means 51, 52, 53 are interlinked via the optical branch output terminal section and the optical coupling input terminal section provided to each of the optical branch coupling means 51, 52, 53.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a branch switching device for optical fiber cables, and more particularly to a branch switching device for optical fiber cables of an optical submarine cable system.

[0002]

2. Description of the Related Art A conventional branching device converts an optical signal into an electric signal, has an electric switch circuit, and switches the signal by the electric switch circuit.

[0003]

In the line switching by the conventional electric circuit, in the optical submarine cable system by the optical amplifier, the modulation signal for monitoring superposed on the optical signal is converted from the optical signal to the electric signal by the branching device. It is difficult to apply because it cuts off when it is applied. In addition, OTDR (Opt
There was a problem that the optical fiber cable failure point search using the ical time domain reflectometer (measuring device used for optical communication) was impossible.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to improve the inconvenience of the conventional example, and in particular, to make a branch switching device for an optical fiber cable capable of automatically recombining three branches without converting an optical signal into an electric signal. The purpose is to provide.

[0005]

According to the present invention, an optical fiber cable that is branched in three directions and laid independently is provided.
The optical fiber cable branching region is formed by directly connecting the optical fiber cable to the second direction, from the second direction to the third direction, and from the third direction to the first direction. An optical branching / coupling means having an optical branching function and an optical coupling function is provided at a connection point of each optical fiber cable in the area, and an optical branching output terminal portion provided in each optical branching / coupling means is optically coupled. The configuration is such that adjacent optical branching / coupling means are connected to each other via the input terminal portion. This aims to achieve the above-mentioned object.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the embodiment shown in FIGS. 1 and 2, an optical fiber cable 40 which is branched in three directions and laid independently is arranged from a first direction to a second direction, and from a second direction to a third direction. Further, a branch area for an optical fiber cable is provided, which is directly connected from the third direction to the first direction, and an optical branching function and an optical coupling function are provided at connection points of the optical fiber cables in the branch area for the optical fiber cable. Optical branching / coupling means 51,
52, 53 are equipped. Each of the optical branching / coupling means 51, 52, 53 is mutually connected to the adjacent optical branching / coupling means via the optical branching output terminal section and the optical coupling input terminal section provided for itself.

The optical branching / coupling means 51, 52, 53
Includes an optical coupler 10 _ac, 10 _cb, 10 _ba provided with an optical branching output end optically coupled inputs respectively coupled to the optical coupler 10 _ac, 10 _cb, 10 _ba optical branching output end It has been isolator 20 _ab, 20 _bc, 20 _ca and, wherein the isolator 20 _ab, 20 _bc, 20 optical interrupter 30 allowed to shut off or transmitted as needed branched light sent out via the _{ca ab,} 30 _ca It has 30 _bc .

Then, the optical branching / coupling means 51, 5
When any one of the branch cables has a failure, the reference numerals 2 and 53 serve to disconnect the branch and connect the other branch cables to each other.
This will be described in more detail. The optical branch circuit diagram shown in FIG. 1 normally has the input / output terminals A, B, C through AB, BC, C.
-A is bidirectionally connected.

When the optical couplers 10 _ac , 10 _cb , 10 _{b- a} are provided between the terminals ( _AB , _BC , _CA ), the optical couplers 10 _ac , 10 _cb , 10 _{ba are used.} Coupling of light
Branching is possible. For example, when the fiber cables (40 _b1 , 40 _b2 ) connected to the terminal B are disconnected due to a failure, the opposing fiber cables 40 _a2 , 40 _c2 can operate between the branching device and the terminal station. Since it is idle, it is necessary to connect 40 _a2 and 40 _c2 for effective use.

Details will be described with reference to FIG. The optical signal of 40 _a2 input to the A terminal is branched by the optical coupler (10 _ab ), the isolator (20 _ac ), the optical breaker (30 a).
_ac ) via optical coupler (10 _bc ) to fiber 40
_It is connected to _c2 and output from terminal C. At this time, a part of the optical signal passes through the isolator (20 _ba ) and is coupled to other lines by the optical coupler as miscellaneous light, so the optical breaker (30 _ba ) is closed to prevent this. Then, it is a necessary condition that the reflected light from the optical interrupter is blocked by the isolator (20 _ba ) and does not affect the main line system.

[0011] These can be arbitrarily switched even in the case of failure of the fiber cable in three directions.

Further, by opening the optical breaker 30 at two positions, it is possible to construct a path for a loopback test from one end station, which is characterized in that an optical signal can be easily and arbitrarily switched.

[0013]

As described above, the present invention is an unprecedented excellent optical fiber cable in which it is possible to easily rearrange any of the three branches with an optical signal as it is without converting the optical signal into an electric signal. A branch switching device can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the operation of the embodiment shown in FIG.

[Explanation of symbols]

A, B, C Input / output terminals 10 _ac , 10 _cb , 10 _ba Optical coupler 20 _ab , 20 _bc , 20 _ca Optical isolator 30 _ab , 30 _ca 30 _bc Optical circuit breaker 40 _a1 , 40 _a2 , 40 _b1 , 40 _b2 , 40 _c1 , 40 _c2 Fiber cable 51, 52, 53 Optical branching / coupling means

Claims (3)

[Claims] 1. An optical fiber cable which is branched in three directions and laid independently is provided from a first direction to a second direction, from a second direction to a third direction, and from a third direction to a first direction. Optical fiber cable branching regions are formed by direct connection in the respective directions, and optical branching / coupling means having an optical branching function and an optical coupling function are provided at connection points of the optical fiber cables in the optical fiber cable branching regions. At the same time, the branch switching for an optical fiber cable is characterized in that adjacent optical branching / coupling means are interconnected via an optical branching output terminal section and an optical coupling input terminal section provided in each optical branching / coupling section. apparatus. 2. The optical branching / coupling means includes an optical coupler having an optical branching output end and an optical coupling input end, an isolator connected to the optical branching output end of the optical coupler, and an isolator therefor. 2. The branch switching device for an optical fiber cable according to claim 1, further comprising an optical breaker for blocking or transmitting the branched light sent out through the optical fiber as required. 3. The optical branching / coupling means functions to disconnect the branch and to connect other branch cables to each other when a failure occurs in any of the branch cables. Item 1. A branch switching device for an optical fiber cable according to item 1 or 2.