| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical branching filter capable of clearly separating a signal of each channel of light whose waveform is multiplexed from noise. SOLUTION: The optical branching filter has a light receiving element array which separates branched light into a signal and noise every branched light, and receives them. The light receiving element array is formed by alternately arranging signal monitoring light receiving elements 1, 3, etc., (2N-1) and noise monitoring light receiving elements 2, 4, etc., 2N, signal intensity is monitored with an output monitoring light receiving element, and noise intensity is monitored with a noise monitoring light receiving element. |
