Pulsewidth tunable CSRZ DQPSK signal generation using DPMZMs

This letter proposes and experimentally demonstrates a simple scheme for generating 40-GBaud carrier-suppressed return-to-zero differential quadrature phase shift keying (CSRZ-DQPSK) modulation signals with tunable pulsewidths using two dual-parallel Mach–Zehnder modulators (DPMZMs). The duty cycle