Efficient telecom to visible wavelength conversion in doubly resonant gallium phosphide microdisks

摘要

Resonant second harmonic generation between 1550nm and 775 nm with normalized outside efficiency ＞3.8 × 10~(-4)mW~(-1) is demonstrated in a gallium phosphide microdisk supporting high-Q modes at visible (Q ～ 10~4) and infrared (Q ～ 10~5) wavelengths. The double resonance condition is satisfied for a specific pump power through intracavity photothermal temperature tuning using ～360μW of 1550 nm light input to a fiber taper and coupled to a microdisk resonance. Power dependent efficiency consistent with a simple model for thermal tuning of the double resonance condition is observed.