M. Vaeziravani et al., DETECTION OF HIGH-FREQUENCY AND LOW-FREQUENCY VIBRATIONS USING A FEEDBACK-STABILIZED DIFFERENTIAL FIBER OPTIC INTERFEROMETER, Optical engineering, 32(8), 1993, pp. 1879-1882
Highly sensitive and stable detection of minute ac and pseudo-dc (i.e.
, very low frequency) vibrations is performed by means of a differenti
al fiber optic Michelson interferometer. Any residual instabilities ar
e eliminated by means of an ac feedback control loop. The stabilizatio
n technique is not affected by the variations in the reflectivity of t
he sample and by launch inefficiencies into the fiber. This approach a
lso provides a simple, quantitative method for calibrating sample vibr
ations. Results are presented on the operation of the system in stabil
izing its output as well as on the detection of the vibration of a sil
icon sample.