High-sensitivity interferometric accelerometer

Abstract

An accelerometer facilitates optical, interferometric measurement of acceleration. The device includes a proof mass having a first set of spaced-apart, elongated fingers projecting therefrom, and a stationary housing or substrate comprising a second set of similarly arranged projecting fingers. A spring connects the proof mass to the substrate such that, in a rest configuration, the first and second set of fingers interdigitate. When the structure is accelerated, the substrate fingers remain stationary, while the alternating fingers of the proof mass are displaced therefrom. This creates a phase-sensitive diffraction grating which, when illuminated, facilitates determination of the relative displacement between the sets of fingers by measuring the intensity of the diffracted modes. This displacement, in turn, indicates the acceleration experienced by the accelerometer structure.

Dependencies are inferred from the claim text.