Lithium Niobate Optomechanical Disk Resonators

TL;DR

This paper reports the fabrication of high-quality lithium niobate disk resonators on silicon, demonstrating optomechanical interactions and acousto-optic modulation at 56MHz with high optical and mechanical quality factors.

Contribution

It introduces a novel MEMS fabrication process for free-standing lithium niobate resonators with high optical and mechanical Q factors, enabling optomechanical applications.

Findings

High optical Q factor of 484,000 achieved

Demonstrated acousto-optic modulation at 56MHz

Mechanical Q of 2700 for radial breathing mode

Abstract

Lithium Niobate (LN or just niobate) thin-film micro-photonic resonators have promising prospects in many applications including high efficiency electro-optic modulators, optomechanics and nonlinear optics. This paper presents free-standing thin-film lithium niobate photonic resonators on a silicon platform using MEMS fabrication technology. We fabricated a 35um radius niobate disk resonator that exhibits high intrinsic optical quality factor (Q) of 484,000. Exploiting the optomechanical interaction from the released free-standing structure and high optical Q, we were able to demonstrate acousto-optic modulation from these devices by exciting a 56MHz radial breathing mechanical mode (mechanical Q of 2700) using a probe.