| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the optical power loss and also to reduce the scales of the device and system by driving a 1st or 2nd pumping laser beam source. SOLUTION: The 1st and 2nd rare earth dope optical fibers 5 and 6 are connected to an optical fiber 1 of the input side. When the pumping light is inputted to the fiber 5 from a 1st pumping laser beam source 7, the optical signal received from the fiber 1 is amplified and outputted. Then this optical signal is damped by the fiber 6. When the pumping light is inputted to the fiber 6 from a 2nd pumping laser beam source 8, the optical signal received from the fiber 1 is amplified and outputted. Then this optical signal is damped by the fiber 5. Both beam sources 7 and 8 are selectively driven, so that the transmission lines of optical signals are switched. In such a constitution, the optical signal loss can be eliminated and the scales of these device and system can be reduced. Then the device and system can be easily applied also to a submarine cable. |
