SEMICONDUCTOR OPTICAL AMPLIFYING/CONVERTING DEVICE

摘要

PROBLEM TO BE SOLVED: To output an electric signal outputted from a semiconductor optic/ electric converting element for signal while being accompanied with the electric noise as a signal accompanied with no electric noise based on optical noises by adding an electric noise in that electric signal so as to be canceled with an electric noise outputted from a semiconductor optic/electric converting element for noise. SOLUTION: A semiconductor optical amplifier 2 for signal outputs an optical signal L2 as an optical signal L2+LN accompanied with an optical noise LN self-generated inside. A semiconductor optic/electric converting element 5 for signal outputs an electric signal H+HN accompanied with an electric noise HN based on the optical signal LN to an output line 6 and a semiconductor optical amplifier 2' for noise has a configuration similar to the semiconductor optical amplifier 2 for signal and does not input a target optical signal L1 but outputs an optical noise LN' self-generated inside similar to the optical noise LN self-generated inside the semiconductor optical amplifier 2 for signal. In this case, the electric noises HN and HN' in an electric signal H+HN-HN' provided on the output line can be provided with almost the same value.