Patent ID: 9698929
Date: 2017-07-04
CPC Classifications: H04B,H04J

Claim:
1. An optical receiver that receives a wavelength multiplexed optical signal including a plurality of wavelength channels, a superimposition signal being superimposed by frequency modulation on each of the wavelength channels, the optical receiver comprising: an optical filter that filters the wavelength multiplexed optical signal; a photo detector that generates an intensity signal representing a change in an intensity of output light of the optical filter; an amplitude detector that detects an amplitude of the intensity signal output from the photo detector; a signal detector that detects, according to the intensity signal generated by the photo detector, a superimposition signal superimposed on a specified wavelength channel; an error detector that detects an error in the superimposition signal detected by the signal detector; and a filter controller that controls a wavelength of a transmission band of the optical filter according to the amplitude detected by the amplitude detector and the number of errors detected by the error detector, wherein the filter controller controls the wavelength of the transmission band of the optical filter so that the amplitude of the intensity signal detected by the amplitude detector increases, and then controls the wavelength of the transmission band of the optical filter so that the number of errors in the superimposition signal detected by the signal detector is reduced.