Pulsed Sagnac Loop Phase-Modulated Microwave Photonic Link

We present a novel Sagnac loop phase-modulated microwave photonic link with a pulsed optical source. Unlike a conventional Sagnac loop, the optical phase offset of the loop can be adjusted to quadrature by applying a synchronized modulation signal to an in-loop phase shifting phase modulator. Thereby, it exemplifies the fundamental RF response. With balanced detection, a proof-of-concept link demonstrated an output noise floor of -164 dBm/Hz, which is similar to 4 dB above the shot noise floor, and a spurious free dynamic range of 104.8 dB Hz(2/3).