Second harmonic generation in free-standing lithium niobate photonic crystal L3 cavity

We report on second harmonic generation in a photonic crystal L3 cavity drilled in a thin self-suspended lithium niobate membrane. The cavity, resonant for the pump beam in the telecom wavelength range, exhibits a quality factor of around 500. Second harmonic generation has been measured with a low power continuous laser. A conversion efficiency of 6.4×10-9 has been estimated with an input coupled power of 53 µW.