Monolithically integrated membrane-in-the-middle cavity optomechanical systems

Abstract

We describe curved-mirror Fabry-Perot cavities with embedded silicon nitride membranes, fabricated using a monolithic surface-micromachining process. The presence of the suspended membranes was confirmed by confocal microscopy, and their properties were verified through optical studies and thermomechanical calibration of mechanical/vibrational noise spectra measured at room temperature and atmospheric pressure. The cavities exhibit reflectance-limited finesse ( F ∼ 10 3 ) and wavelength-scale mode volumes ( V M ∼ 10· λ 3 ). The short cavity length ( L ∼ 2· λ ) results in large optomechanical coupling, which is desirable for numerous applications in sensing and quantum information.