Large Phase Sensitive Gain in Periodically Poled Lithium–Niobate With High Pump Power

We investigate phase-sensitive operation at telecommunication wavelengths in periodically-poled lithium-niobate waveguides, measuring a record phase-dependent dynamic range of 14.5 dB with 5-dB phase-sensitive gain, compared to phase-insensitive operation. We also highlight limitations arising at high pump powers from green light emission and thermal instability which limits performance compared with an ideal theoretical model.