Single PPLN SHG waveguide for full C band tuning range with watt level output through the engineered QPM structure

Abstract

A large wavelength tuning range MgO-doped periodically poled lithium niobate (PPLN) ridge waveguide is fabricated. Using the iterative domino algorithm, an engineered quasi phase matching (QPM) structure has been implemented to the ridge waveguide, which forms 7 wavelength conversion peaks. Each designed conversion peak has equally nonlinear strength and 5nm wavelength separation, locates from 1530nm to 1560nm at 40 deg. C. Combined with temperature adjustment between 15 to 60 deg. C, which could tune each phase matching peak for more than 5nm, full C band tuning range is achieved with high conversion efficiency. Under CW 5.5W single frequency C band input, 3.7W is coupled to the waveguide, and 2.5W SHG is generated.