Sum-frequency generation in lithium-niobate-on-insulator microdisk via modal phase matching

Whispering-gallery-mode microresonators, one of the most important components of photonic integrated circuits, have the ability to dramatically boost light–matter interactions. In this Letter, we demonstrate effective sum-frequency generation via modal phase matching in a triply resonant lithium-niobate-on-insulator microdisk resonator through two individual continuous wave pumps working in the communication band. The sum-frequency conversion efficiency is measured to be 2.22 × 10 − 6 m W − 1 . This work shows a high-efficiency frequency convertor that may be applied in on-chip integrated optics in the future.