Photonic phase-locked-loop linear phase demodulator

Design and experimental validation of a simple photonic phase-locked-loop (PPLL) linear phase demodulator employing a novel attenuating counter propagating (ACP) in-loop phase modulator are presented. The ACP in-loop phase modulator is free of propagation delay, allowing stable operation of the PPLL with large gain. Highly linear optical phase demodulation was observed and the measured spurious free dynamic range (SFDR) is 134 dBHz^2/3 at 100 MHz bandwidth.