Experimental demonstration of reduced complexity 43-Gb/s RZ-DQPSK rate-tunable receiver

We demonstrate an alternative differential quadrature phase-shift keying (DQPSK) receiver offering reduced complexity through sharing of hardware in the I/Q demodulation paths. Demodulation of 43-Gb/s return-to-zero DQPSK is demonstrated without penalty relative to a traditional DQPSK receiver. Rate tuning is demonstrated using a tunable birefringent element.