Differential Phase Shift Keying for High Spectral Efficiency Optical Transmission

Differential phase shift keying (DPSK) optical transmission has attracted much attention in research and development during the last several years. An overview of DPSK for high spectral efficiency optical transmission is presented in this chapter. The performance of DPSK, such as receiver sensitivity and tolerance to fiber nonlinearity, is discussed in detail. A simplified method for estimating the performance of phase shift keying in numerical simulations is explained. The implementations of DPSK transmitter and receiver are also described. Results of experimental and numerical investigations of several phase shift keying formats, including polarization division multiplexing and multilevel encoding, are briefly reviewed. Finally, methods for further enhancing the performance of DPSK signals in long haul transmissions, particularly the compensation of nonlinear phase jitter, are presented