Optical transmission system, optical transmitter and methods thereof

摘要

To extend a distance of polarization-multiplexing, an optical transmitter in an optical transmission system has a first signal light output unit (24A, 124A) to output a first signal light (S1) of linear polarization to carry a first data (D1) using VSB modulation having one of sideband on a short wavelength side and sideband on a long wavelength side, a second signal light output unit (24B, 124B) to output a second signal light (S2) of linear polarization to carry a second data (D2) using VSB modulation having the other of sideband on a long wavelength side and sideband on a long wavelength side, and an optical coupler (26, 126) to couple the first signal light (S1) and the second signal light (S2) under different polarizations and output the coupled signal lights onto the optical transmission line (12, 112). <IMAGE>