Pressure sensing with high-finesse monolithic buckled-dome microcavities

Abstract

We describe the use of on-chip budded-dome Fabry-Perot microcavities as pressure sensing elements. These cavities, fabricated by a controlled thin-film buckling process, are inherently sealed and support stable optical modes (finesse >10(3)), which are well-suited to coupling by single-mode fibers. Changes in external pressure deflect the buckled upper mirror, leading to changes in resonance wavelengths. Experimental shifts are shown to be in good agreement with theoretical predictions. Sensitivities as large as similar to 1 nm/kPa, attributable to the low thickness (<2 mu m) of the buckled mirror, and resolution similar to 10 Pa are demonstrated. We discuss potential advantages over traditional low-finesse, quasi-planar Fabry-Perot pressure sensors. (C) 2021 Optical Society of America