Nonlinear phase noise in pulse-overlapped transmission based on return-to-zero differential-phase-shift-keying

Pulse-overlapped transmission employing RZ-DPSK is investigated. The nonlinear phase noise from Gordon-Mollenauer effect is reduced, while there exists another noise source resulting from intrachannel FWM. Simulations show superior 40-Gbit/s RZ-PDSK transmission over a NZDSF link