| 摘要 |
PROBLEM TO BE SOLVED: To provide a back flow light interrupting device, in which it is unnecessitated to provide optical distributors in order to detect transmission lights and productivity is improved, which is small in size and also can be suppressed in transmission loss. SOLUTION: This device is made to be a back flow light interrupting device obtaining detection light from multiple reflection lights generated between optical fiber end face and lens surface in input-output ends. That is, in the back flow interrupting device constituted by providing lenses 24, 32, polarizers 26, 30 and a rotator 28 in between the optical fiber 14 of the input end and the optical fiber 42 of the output end, optical fibers 18, 38 are extended in ferrules 20, 36 at least fixing the optical fiber of one side and reflection lights 22, 34 and taken out from the extended optical fibers to be made to be detection lights 16, 40. As a result, reflection lights flowing back to the optical fibers of the input-output ends are suppressed and an isolator function and a detection function are made compatible by making loss small as much as possible. |
