NON-HIT BRANCHING AND JOINING METHOD FOR OPTICAL PATH

PURPOSE:To switch optical communication without hit and to make the optical power level of the termination of an optical fiber being a switching destination the same as that of the termination of the optical fiber being a switching origin. CONSTITUTION:Light transmitted through the optical fiber 1 is branched by local detection from the branching part 3 of the optical fiber 1 on an optical transmitter 2 side; the branched light is received by a photodetector 4; an electrical signal O/E converted by the photodetector 4 is E/O converted by an E/O converter 5 and enters other optical fiber 6 from its one end 7; and the light is joined to the optical fiber 1 from a joining part 9 provided on the optical receiver 8 side of the optical fiber 6. After the E/O converted light is amplified, it enters the optical fiber 6. The light is joined by local injection in the joining part 9. The light is joined by an optical coupler in the joining part 9. The branching ratio of the optical coupler is set to 1:1.