Power and optical frequency monitoring system and transmission system of frequency-modulated optical signal

摘要

The present invention relates to a monitoring system that observes the power and optical frequency of a frequency-modulated optical signal, which is utilized in the communication network employing the WDM (wavelength division multiplexing) method. The monitoring system comprises demultiplex means for demultiplexing the frequency-modulated optical signal outputted from a transmitter including frequency-modulation means, photo-detection means for converting the output of demultiplex means into an electrical signal, and extraction means for extracting the power and optical frequency of an optical signal by measuring the magnitude of an amplitude-modulated tone.