Novel Optical Phase Demodulator Based on a Sampling Phase-Locked Loop

摘要

A novel phase-locked coherent demodulator, based on a sampling phase-locked loop, is presented and investigated theoretically. The demodulator is capable of operating at high frequencies, by using optical sampling to downconvert the high-frequency input radio-frequency signal to the frequency range of the baseband loop. We develop a detailed theoretical model of the (sampling) phase-locked coherent demodulator and perform detailed numerical simulations. The simulation results show that the operation of the sampling demodulator resembles the operation of the baseband demodulator for very short optical pulses ($<$2 ps). Furthermore, we investigate how the signal-to-noise ratio of the demodulator is affected by timing and amplitude jitter of the pulsed optical source.