Efficient second harmonic generation in an on-chip high-Q crystalline microresonator fabricated by femtosecond laser

Abstract

We report on transiently phase matched second harmonic generation in an on-chip lithium niobate (LN) microresonator fabricated by femtosecond laser direct writing followed by focused ion beam milling. We demonstrate a normalized conversion efficiency of 1.1×10-3/mW in the LN microdisk with a diameter of ~102 μm and a thickness of ~700 nm.