Optical accelerometer with mechanical amplification via a V-beam mechanism

Abstract

A method is reported for improving the performance of a Fabry-Pérot optical accelerometer, based on the use of a V-beam mechanism to amplify the proof mass displacement. Amplification allows the sensitivity to be increased without compromising bandwidth or requiring an increase in cavity finesse. An analytical expression relating the amplification factor to the V-beam length, width and angle was derived and used to produce a series of differently angled devices. A 1.9° device was capable of detecting accelerations from 0.01 to 10 g rms. The 1.33° accelerometer produced an amplification of 18.6 ± 6.4.

Remote Photothermal Actuation for Calibration of In-Phase and Quadrature Readout in a Mechanically Amplified Fabry–Pérot Accelerometer

“…In this paper, we demonstrate the use of remote photothermal actuation for calibration of a mechanically amplified FPI optical accelerometer with I&Q readout. This work extends our earlier investigation of mechanical amplification in optical accelerometers using V-beam structures, as reported in [17], [18]. A schematic of the device investigated in the present work is shown in Fig.…”

Mechanically amplified MEMS optical accelerometer with FPI readout

“…The accelerometer design was similar to those reported by us in earlier papers 10,11 . The proof mass, with dimensions 1.978  1.978 mm 2 , was supported on a hammock suspension comprising six flexures, each 1.6 mm long and 78 µm wide.…”

“…In earlier work we demonstrated a MEMS FPI accelerometer in which the proof mass motion is mechanically amplified by a V-beam mechanism 10,11 . In this paper we present further experimental results for this device, and also demonstrate a novel method for remote calibration based on photothermal actuation using fibre-delivered light.…”