JP2001343533A - Exciting bar for contrasting optical cable of interference type - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a case of the failure in judgement caused by weak tapping strength due to the difference among individuals in the use of a discriminating method by tapping an optical cable with an exciting bar at the time of discriminating the objective optical cable to be contrasted (or removed, and so on) by using an optical cable comparator. SOLUTION: This exciting bar is used for the optical cable comparator utilizing an optical loop interferometer and is constituted by interposing a spring between a grip part and a head.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical cable contrast technology for comparing an optical cable or an optical fiber core when an optical cable or the like currently laid is to be removed due to aging or the like. In particular, it relates to a vibrating rod structure used for the optical cable contrast.

[0002]

2. Description of the Related Art For example, when switching or removing optical fiber cables along roads or in manholes,
Optical cable comparison is performed to identify a target optical cable from among a large number of optical cables to prevent accidental disconnection of the optical cable. Similarly, at the time of optical fiber switching work, an optical fiber core comparison is performed to identify a target optical fiber core from a number of optical fiber cores in a cable.

[0003] As a contrast method, for example, a light source and an optical splitter that splits light from the light source into two optical cables are connected to one end of two cables, a reference optical cable and a reference optical cable. At the end, an optical multiplexer for multiplexing and interfering the propagation lights of the two optical cables and an optical receiver for receiving the interference light from the optical multiplexer are connected, and the phase change of the propagation light of the two optical cables is detected. There is a method of using a Mach-Zehnder interferometer type optical cable comparator configured to output from a receiver to apply vibration to the cable, monitor an output signal, and compare the target optical cable.

Further, both ends of a loop-shaped optical fiber are connected to an optical coupler, light from a light source is split into two systems by the optical coupler, and light in the loop is multiplexed (interference) again using the optical coupler. ) And receive light with a photodetector. There is a method of vibrating the optical fiber cable and using the intensity change of the interference light to compare the optical cables.

In the above optical cable contrast method, an optical cable to be compared (removed) is determined by hitting the optical cable with a vibrating rod to apply vibration.

[0006]

Heretofore, in many cases, an optical cable comparator has been used to determine a target optical cable to be compared by striking it with a metal xylophone rod shape 30 shown in FIG. At that time, it is necessary to hit the optical cable with a certain force, and if the force is weaker than that, the optical cable may not be easily distinguished from noise or the like and may not be distinguished.

[0007] Further, the vibration intensity applied by a human varies. Depending on the person, the strength may be weak even if the player intends to hit, and the judgment may not be possible.

According to the present invention, when working with an optical cable contrast device, that is, when an operator hits the optical cable to vibrate the optical cable, the vibrating rod having a structure to which a force is easily applied causes a shortage of force. The purpose is to prevent indistinguishability as much as possible.

[0009]

In order to achieve the above-mentioned object, a cable-controlling vibrating rod according to the present invention splits light from a light-emitting element into two systems and propagates the light to an optical fiber.
The light propagated to the system is multiplexed and interfered, the interference light is input to a light receiving element, and a phase change when a desired excitation point of the optical cable containing the optical fiber is excited is output from the light receiving element. In the interference type optical cable control in which the control cable is discriminated by performing the vibration, the vibrating rod for vibrating is configured by interposing a spring between the grip portion of the rod-shaped body and the head. What we did

With the vibrating rod having the above-described structure, the head is accelerated by the spring when the worker hits the cable, so that the cable can be given an impact greater than the force of the worker.

[0011]

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

In the optical cable contrast operation, a target optical fiber cable is searched from a large number of cables laid at a work site such as a manhole. In that work, for example, at the telephone station or relay station, the cable decided to be exchanged is separated from the optical transmission and reception equipment and work is started, and the removal work proceeds in order, so both ends of the target optical cable are specified . However, since a large number of cables are laid at the intermediate point, the control cable cannot be immediately identified.

Therefore, a target optical cable is compared from a large number of cables using the optical cable comparator shown in FIG.

FIG. 2 is a block diagram showing the basic structure of the optical cable comparator, wherein the optical cable comparator 101 includes a control optical cable 103 at one end thereof.
Light-emitting element 111, light-receiving element 113, and branch-coupling element 112 connected to any two optical fibers 105, 106
It is composed of At the point where the optical cable contrast operation is performed, the impact is given to each of a large number of optical cables in turn by hitting with the vibrating rod 10. At the other end 104 of the control optical cable, the optical fiber 10
Reference numerals 5 and 106 are connected to the optical delay element 102 (drum around which an optical fiber is wound).

With such a configuration, the optical cable comparator 1
The optical signal having a constant output from the light emitting element 111 of the first optical fiber 101 is transmitted to the two optical fibers 105 and 1 through the branch coupling element 112.
06, the light is propagated from each end in the clockwise direction A and the counterclockwise direction B.

The propagation light of the optical fibers 105 and 106 returns after receiving a predetermined phase change,
And causes interference due to the phase difference between the two, and is output to the light receiving element 113. Therefore, the phase change of the light in the clockwise direction A and the counterclockwise direction B is output as a change in the intensity of the output of the light receiving element 113. You. Unless vibration or the like is applied to the optical fibers 105 and 106 from the outside to cause a phase change, interference occurs at a constant phase difference. Therefore, a signal of a constant intensity is output from the light receiving element 113. Therefore, when the operation of "hitting" with the excitation rod 10 is performed, a phase change occurs in the propagating light, and the light interference phenomenon changes. This change can be detected by observing the output signal of the light receiving element 113.

Therefore, an impact is applied to the midpoint of each of the large number of optical cables by the vibrating rod 10 in order.
If there is a cable showing a change in the output signal from the light receiving element 113 in the optical cable comparator 101, it can be determined that the cable is the reference cable 103.

As shown in FIG. 1, the structure of the vibrating rod 10 includes a head (other than a circle) 11, a spring part 12,
And a grip portion 13.

In the embodiment of the present invention, the case where the two optical fibers 105 and 106 are accommodated in the same optical cable has been exemplified. However, the present invention is not limited to such a form. The present invention is also applied to a case where the optical cables are accommodated in different optical cables. That is, the optical fiber 105
And 106 are connected at one end to form a loop-shaped optical fiber, so that the optical cable according to the present invention can be compared with an optical cable in which at least one of the two is accommodated.

In the present invention, the optical delay element 102 is not always essential. However, when the point at which the vibration is applied by the vibrating rod 10 is near the midpoint of the length of the looped optical fiber, the phase changes of the clockwise direction A and the counterclockwise direction B cancel each other and interfere. As a result, the output signal corresponding to the vibration decreases, so that the optical delay element 102 is required to prevent this.

Further, in the vibrating rod of the present invention, a light source and an optical splitter for splitting light from the light source into two optical cables are connected to one ends of two cables of a control optical cable and a reference optical cable. At the opposite end, an optical multiplexer for multiplexing and interfering the propagation lights of two optical cables and an optical receiver for receiving the interference light from the optical multiplexer are connected, and the phase change of the propagation light of the two optical cables is connected. Can also be applied to a Mach-Wender interferometer-type optical cable contrast device having a configuration in which is output from an optical receiver.

[0022]

By using the vibrating rod of the present invention, the head is accelerated by the spring when the worker hits the optical cable, so that the cable can be given an impact greater than the force of the worker. Judgment) probability has been greatly improved.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a vibrating rod according to the present invention.

FIG. 2 is a block diagram showing a basic configuration of an optical cable comparator according to the present invention.

FIG. 3 is an explanatory view of a conventional vibrating rod.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vibration rod 101 Optical cable contrast device 102 Optical delay element 103 Optical cable 105, 106 Optical fiber

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toru Takashima 1440, Mukurosaki, Sakura-shi, Chiba Prefecture Fujikura Co., Ltd. Sakura Plant (72) Inventor Shinichi Nikaido 1440, Mukurosaki, Sakura-shi Chiba Prefecture Fujikura Co., Ltd. Sakura Plant F-term (reference) 2G086 AA01 2H038 CA39 5G369 AA16 BA05 BA06 EA03

Claims (1)

[Claims] The light from a light emitting element is branched into two systems and propagated through an optical fiber. The lights propagated through the two systems are combined and interfered with each other, and the interference light is input to a light receiving element. In an interference type optical cable control, in which a phase change when a desired excitation point of an optical cable containing a fiber is excited is output from a light receiving element to determine a reference cable, a vibration rod for the excitation is used. An interference type optical cable contrasting excitation rod characterized in that the excitation rod is constituted by interposing a spring between the grip portion of the rod-shaped body and the head.