A Phase Stable Short Pulses Generator Using an EAM and Phase Modulators for Application in 160-GBaud DQPSK Systems

We demonstrate 40-GHz phase stable short optical pulses generation using an electroabsorption modulator and cascaded phase modulators. The pulses are characterized with a small pedestal,~2.1-ps pulsewidth, an extinction ratio larger than 23 dB, timing jitter less than 60 fs, and an optical signal-to-noise ratio over 40 dB over 30-nm tuning range. The high quality and phase stability of the pulses are further experimentally verified in a 4\,×\,40 GBaud differential quadrature phase-shift-keying (DQPSK) optical-time-division-multiplexing (OTDM) system.