Patent ID: 8244138

Claim:
A polarization-multiplexing optical receiver comprising: a polarization controller that controls polarization states of externally received polarization-multiplexing signals; a polarization splitter that splits, upon respectively extracting, from the polarization-multiplexing signals of which the polarization states are controlled by the polarization controller, a first polarization component and a second polarization component orthogonal to each other; a first optical receiver that receives the first polarization component split by the polarization splitter, and externally transmits a first input signal detected from the first polarization component, the first optical receiver having a first band-pass filter that changes an intensity of the first polarization component according to a wavelength swinging of the received first polarization component, and a first low-speed photodiode that converts the first polarization component output from the first band-pass filter into first electric signals; a second optical receiver that receives the second polarization component split by the polarization splitter, and externally transmits a second input signal, differing from the first input signal, detected from the second polarization component, the second optical receiver having a second band-pass filter that changes an intensity of the second polarization component according to a wavelength swinging of the received second polarization component, and a second low-speed photodiode that converts the second polarization component output from the second band-pass filter into second electric signals; a first detector that extracts a first pilot signal component and a second pilot signal component included in the first electric signals output from the first low-speed photodiode; a second detector that extracts a first pilot signal component and a second pilot signal component included in the second electric signals output from the second low-speed photodiode; and a controller that calculates a first ratio of the first pilot signal component and the second pilot signal component included in the first electric signals, calculates a second ratio of the first pilot signal component and the second pilot signal component included in the second electric signals, and controls the polarization controller based on the first ratio calculated and the second ratio calculated, wherein the first pilot signal is superimposed on the first polarization component and the second pilot signal is superimposed on the second polarization component.