| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical fiber amplifier which can reduce the loss of excited light and has a simplified structure. SOLUTION: A laser 3 for excitation is connected to one end of an optical fiber 2 for amplification through a wavelength multiplexer/demultiplexer 4 and another wavelength multiplexer/demultiplexer 12 having four ports is connected between the other end of the fiber 2 and another optical fiber 13 for amplification. Then, the two ports of the multiplexer/demultiplexer 12 are connected to the optical fibers 2 and 13, and the other two ports are connected to two lasers 5 and 6 for excitation. Since the excited light emitted from the lasers 5 and 6 are incident to the optical fibers 2 and 13, the signal light which passes through the optical fibers 2 and 13 can be amplified. |
