Return-to-zero quaternary differential-phase amplitude-shift- keying for long-haul transmission
23 February 2004
Return-to-zero (RZ) quaternary differential-phase ASK modulation with 20-Gb/s aggregate data-rate is implemented with both optical and electrical RZ pulse generation. A simple pre-chirping scheme is proposed to improve its nonlinear tolerance in long-haul transmission. Ó2003 Optical Society of America OCIS codes: (060.4080) Modulation; (060.4370) Nonlinear optics, fibers.