US Patent 9668036 Optical transmission system using optical frequency comb sources

A system includes an optical transmitter and an optical receiver. The optical transmitter includes a first comb light source, a second comb light source, an optical switch configured to selectively switch either the first comb light source or the second comb light source through to an output of the optical switch, and optical modulators configured to apply differential phase modulation, to channels associated with the switched first comb light source or with the second comb light source, to generate modulated light output signals. The optical receiver includes coherent receivers configured to receive the modulated light output signals from the optical transmitter, and detect and process the received, modulated light output signals to generate corresponding digital signals. The optical receiver further includes a digital signal processor configured to apply forward error correction to the digital signals to generate forward error corrected digital signals.