A simple optical transducer for the measurement of small vibration amplitudes

Abstract

An optical displacement transducer, based on commercially available photodetectors, has been developed. The linearity and frequency response are analysed and the results presented show a useful dynamic range of 500 mu m at a frequency up to 50 kHz. Immunity from gross misalignment is noted. Practical designs are illustrated with an application to amplitude monitoring of ultrasonic transducers.