OPTICAL ADD-DROP MULTIPLEXER

摘要

Input light includes a multicarrier signal and first CW light of a first optical frequency. A transmitter (39) generates a modulated optical signal based on an inverted signal of a dropped signal. A light source (41) generates second CW light of a second optical frequency. A delay element (40, 42) adjusts a phase difference between the modulated optical signal and the second CW light. The multicarrier signal, the first CW light, the modulated optical signal and the second CW light are input to nonlinear optical medium (45). A detector (51) detects beat frequency component between the modulated optical signal and the second CW light. A controller (52) controls the delay element (40, 42) so as to increase the beat frequency component. A difference between the first optical frequency and an optical frequency of the dropped optical signal is substantially the same as a difference between the second optical frequency and an optical frequency of the modulated optical signal.