Patent ID: 7016611

Claim:
An optical communications system comprising: a transmitter including: a plurality of time-division multiplexing devices each having mutually different frequencies, each of said plurality of transmitting time-division multiplexing devices time-division multiplexing a first optical signal sequence and a second optical signal sequence having a π phase difference therebetween to generate an optical data sequence, a duty ratio of said first optical signal sequence and of said second optical signal sequence being from 0.52 to less than 0.56; and an optical multiplexer, said optical multiplexer wavelength division multiplexing said optical data sequence from each of said plurality of time-division multiplexing devices; an optical communications line that propagates said wavelength multiplexed optical data sequence, in which a dispersion management parameter of the optical communications line is from 2.6 to less than 3.3; and a receiver including: an optical demultiplexer that separates said wavelength multiplexed optical data sequence received from said optical communications line by wavelength into a plurality of time-division multiplexed optical data sequences; and a plurality of time-division demultiplexers that separate said plurality of received time-division multiplexed optical data sequences received from said optical demultiplexer by time.