DIAMOND HEMISPHERICAL RESONATOR FABRICATION BY ISOTROPIC GLASS ETCH

Abstract

We have fabricated polycrystalline diamond hemispheres by Hot-Filament CVD (HFCVD) in spherical cavities wet-etched into a novel high temperature glass substrate. These resonators are 1.4 mm in diameter and have a Q of up to 143,000 in the fundamental wineglass mode, for a ringdown time of 2.4 seconds. Asfabricated resonators have the two degenerate modes frequency matched to as close as 7 Hz, or 0.04% of the resonant frequency (~16 kHz). We have demonstrated laser trimming on a segmented lip resulting in mode matching to better than 0.3 Hz. These resonators show great promise for use as Hemispherical Resonant Gyroscopes (HRGs) on a chip.