| 摘要 |
PROBLEM TO BE SOLVED: To accurately detect frequency modulation signals superposed on optical signals in a designated wavelength channel in a WDM transmission system.SOLUTION: An optical receiver for receiving wavelength multiplex optical signals having frequency modulation signals respectively superposed thereon in a plurality of wavelength channels, includes: an optical filter which filters the wavelength multiplex optical signals; a filter control unit which controls the transmission band wavelength of the optical filter; a light-receiving device which generates an intensity signal representing an intensity change in output light of the optical filter; an amplitude detection unit which detects intensity signal amplitude; a signal detection unit which detects a frequency modulation signal on the basis of the intensity signal; and an error detection unit which detects an error in the frequency modulation signal detected from the intensity signal. The filter control unit controls the transmission band wavelength of the optical filter so as to increase the amplitude of the intensity signal, and thereafter, controls the transmission band wavelength of the optical filter so as to reduce an error in the frequency modulation signal detected from the intensity signal.SELECTED DRAWING: Figure 10 |
