Polarization Diversity Optical Parametric Amplifier By Parallel Periodically Poled Linbo3 Waveguides Module

We demonstrate a polarization diversity optical parametric amplifier (OPA) by a periodically poled LiNbO3 (PPLN) module for fiber-optic communication systems. We have fabricated the PPLN module which consists of two parallel PPLN ridge waveguide devices to amplify orthogonal polarization components of a signal light independently. The dependence of the parametric gain of each PPLN waveguide on the pump light power was investigated based on a cascaded second harmonic generation (SHG) and OPA process. Both PPLN waveguides showed almost the same parametric gain property, which facilitated the gain equalization between the orthogonal polarization components of the signal light. We successfully performed the polarization-independent OPA by adjusting the quasi-phase-matching wavelengths and the gains of the two PPLN waveguides.