Highly efficient phase-sensitive parametric gain in periodically poled LiNbO_3 ridge waveguide

(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.