| 摘要 |
PROBLEM TO BE SOLVED: To enhance reception quality of a signal to be superimposed on the signal light of multiple wavelengths by frequency modulation.SOLUTION: An optical receiver 50 may includes a wavelength variable filter 51, a photodetector 52, and a superimposed signal detector 5313. The wavelength variable filter 51 receives wavelength multiplex light, where a frequency modulation signal is superimposed on the signal light of multiple wavelengths, respectively, and transmits partially to a photodetector (PD)52. The superimposed signal detector 5313 may detect a signal superimposed on the first signal light, based on both first signal light and second signal light adjoining the first signal light on the short wavelength side, passing through the wavelength variable filter 51 and detected by the PD52, and both first signal light and third signal light adjoining the first signal light on the long wavelength side, passing through the wavelength variable filter 51 and detected by the PD52.SELECTED DRAWING: Figure 5 |
