| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical SN detector and method in a coherent optical communication system, that can detect the SN of wavelength multiplex signal lights configured by high density, with high accuracy. SOLUTION: An optical SN detection system of a coherent optical communication, that applies wavelength multiplex to a coherent signal light, including an ASE(amplified spontaneous emission) noise light for communication, is provided with optical filters 15, 119 that transmit the coherent signal light with a prescribed channel wavelength component, a channel ASE noise detection section 114 that optically quenches the transmitted coherent signal light component to detect the signal of the channel ASE noise light component, a channel power detection section 112 that detects the signal of the channel power of the transmitted channel wavelength component, and a detection signal processing section 120 that subtracts the detection signal of the channel ASE noise optical component from the detection signal of the channel power and calculates the optical SN, on the basis of the calculation signal of the channel power of the coherent signal light and the detection signal of the channel ASE noise optical component. |
