| 摘要 |
PROBLEM TO BE SOLVED: To amplify signal light by providing a first stimulation light source and a second stimulation light source which is connected to the other wavelength multiple coupler of an up optical fiber transmission line and to the other wavelength multiple coupler of a down optical fiber transmission line and transmits stimulation light to each rare earth doped optical fiber. SOLUTION: A first stimulation light source 2a is connected to wavelength multiple couplers 4a and 4b on input side of up and down transmission lines through a turnout 3a. A second stimulation light source 2b is connected to wavelength multiple couplers 4c and 4d on output side of up and down transmission lines through a turnout 3b. The first and second stimulation light sources 2a and 2b form a redundant construction. Even when one of the first and second stimulation light sources is out of order, stimulation light is emitted from either the input or the output side of the rare earth doped optical fibers 1a and 1b and the signal light can be amplified. |
