Suppression of influence of homowavelength crosstalk in an optical add/drop multiplexing system by modulating LD light frequency

A scheme for reducing influence of homowavelength crosstalk in an optical add/drop multiplexing network is described. Signal light outputs from center to remote nodes are frequency-modulated as well as intensity-modulated for data transmission. Due to the frequency modulation, interferometric noise between the signal and crosstalk light is suppressed through the baseband filter in the receiver. The feasibility is confirmed in experiments.