Optical communication device

Abstract

An optical communication device for detecting a defect in a standby optical fiber. An active optical output unit converts an electrical signal to an optical signal, and a standby optical output unit is provided as a substitute for the active optical output unit. An optical router is connected to the active optical output unit by an active optical fiber, and is also connected to the standby optical output unit by a standby optical fiber. The optical router outputs the optical signal received from the active optical output unit to the subsequent stage, and also outputs part of the optical signal to the standby optical output unit. A defect detector detects a defect in the standby optical fiber on the basis of the light level of the optical signal output from the optical router to the standby optical output unit through the standby optical fiber.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows an optical communication device.

FIG. 2 shows an exemplary system configuration of optical communication devices.

FIG. 3 shows in detail an optical transmitter, an optical fiber monitor and a redundant multiplexer.

FIG. 4 shows another exemplary configuration of the optical transmitter, optical fiber monitor and redundant multiplexer.

FIG. 5 shows an exemplary system configuration of conventional optical communication devices.

Claims

1. An optical communication device for detecting defects in optical fibers, comprising: active optical output means for outputting an optical signal;standby optical output means provided as a substitute for the active optical output means;an active optical fiber connected to the active optical output means;a standby optical fiber connected to the standby optical output means;optical router means connected to the active and standby optical fibers, the optical router means being adapted to output the optical signal to a subsequent stage and also to output part of the optical signal from the active optical output means to the standby optical output means through the standby optical fiber; anddefect detector means for detecting a defect in the standby optical fiber, based on a light level of the optical signal output from the optical router means to the standby optical output means.

2. The optical communication device according to claim 1, wherein, if the light level is lower than a threshold, the defect detector means judges that the standby optical fiber is defective.

3. The optical communication device according to claim 2, wherein the defect detector means operates with hysteresis in detecting a defect in the standby optical fiber.

4. The optical communication device according to claim 1, wherein the optical signal output to the subsequent stage has a light level higher than that of the optical signal output to the standby optical output means.

5. The optical communication device according to claim 1, wherein the optical router means causes part of the optical signal output from the standby optical output means to enter the active optical output means through the active optical fiber, and the defect detector means detects a defect in the active optical fiber, based on a light level of the optical signal output from the optical router means to the active optical output means.

6. The optical communication device according to claim 1, wherein the active optical output means includes a plurality of active optical output means for outputting optical signals of respective different wavelengths, the standby optical output means includes a plurality of standby optical output means associated with the respective active optical output means,the optical router means includes a plurality of optical router means associated with respective pairs of the active and standby optical output means, andthe defect detector means detects a defect in the standby optical fibers connected to the respective optical router means.

7. The optical communication device according to claim 1, wherein the optical router means comprises couplers.