Highly efficient phase-sensitive parametric gain in periodically poled LiNbO₃ ridge waveguide

We have developed a periodically poled LiNbO₃ (PPLN) ridge waveguide device and experimentally demonstrated a phase-sensitive optical parametric amplification. The highly efficient net phase-sensitive parametric gain of +18.6  dB is obtained in a cascaded second harmonic generation and difference frequency generation configuration. The phase-sensitive gain is greater by +5.8  dB in comparison with the phase-insensitive gain. We successfully confirmed the phase-sensitive amplification with a high gain in the PPLN ridge waveguide.