High Quality Factor Surface Fabry-Perot Cavity of Acoustic Waves

TL;DR

This paper reports the design and experimental realization of high-Q surface acoustic wave Fabry-Perot resonators with quality factors over 13,000, using tapered phononic crystal mirrors on a GaN-on-sapphire platform, advancing quantum acoustics and sensing applications.

Contribution

It introduces a novel high-Q SAW resonator design with tapered phononic crystal mirrors, demonstrating significant loss reduction and mode confinement.

Findings

Intrinsic quality factor exceeds 13,000 at ambient conditions

Standing Rayleigh waves observed inside the cavity

Resonators characterized by electrical and optical methods

Abstract

Surface acoustic wave (SAW) resonators are critical components in wireless communications and many sensing applications. They have also recently emerged as subject of study in quantum acoustics at the single phonon level. Acoustic loss reduction and mode confinement are key performance factors in SAW resonators. Here we report the design and experimental realization of a high quality factor Fabry-Perot SAW resonators formed in between tapered phononic crystal mirrors patterned on a GaN-on-sapphire material platform . The fabricated SAW resonators are characterized by both electrical network analyzer and optical heterodyne vibrometer. We observed standing Rayleigh wave inside the cavity, with an intrinsic quality factor exceeding 13,000 at ambient conditions.