Optical accelerometer with mechanical amplification via a V-beam mechanism

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.