Poling-induced birefringence phase matching for 1.5-μm-band wavelength conversion in a polymeric rib waveguide

Abstract A birefringence phase-matching (BPM) scheme for second harmonic generation, difference frequency generation (DFG), and their cascading is developed in a polymer rib waveguide. Poling-induced birefringence ( n TM – n TE ) of PMMA:DANS side-chain polymer films showed quadratic increase upon applied DC poling fields, and was controlled for satisfying the BPM. The three conversion processes using the nonlinear coefficient of the d 15 were simultaneously phase matched at the poling field around 150 V/μm when the fundamental guiding modes of a pump (DFG: 0.775 μm, cascading: 1.55 μm) and a signal (∼1.55 μm) waves were used. In addition, a numerical simulation of the DFG including the waveguide losses showed high conversion efficiencies around 0 dB on the conditions: the pump power of 100 mW, the waveguide length around 2 cm, and the waveguide losses of 2 dB/cm, demonstrating that the poling-induced BPM is an effective phase-matching method in the wavelength conversion processes.