Tilting-mirror fiber-optic accelerometer

Abstract

Experimental and theoretical results are presented on a simple compact fiber-optic sensor that uses a mirror placed on the end of a mass-loaded cantilevered elastic beam. Deflections of the beam due to acceleration are read out with multimode optical fibers and with a quarter-pitch GRIN rod lens. Two output fibers are used in a balanced-detection scheme. In the audio-frequency range, the minimum detectable acceleration is 2.4 × 10−6 Grms, and the maximum measurable acceleration is 39 Grms. The device is also sensitive to dc accelerations. However, during dc sensing, a fiber bending noise is found. This noise decreases the dynamic range of the accelerometer.