Abstract

Fiber optic sensors using white-light interferometry have been developed, among others, as absolute displacement sensors¹, as strain or temperature sensors². The main advantage of white-light interferometry, which uses broad band light sources with short coherence lengths rather than monochromatic sources, is the possibility to make absolute measurements. In the same manner, a broad band source allows to measure the absolute force from the induced birefringence in an optical fiber (Fig. 1). Scanning the interferogram in space, rather than in time, by a linear photodiode array (electronically-scanned interferometer) avoids moving parts and increases the mechanical stability of the system. In this paper, we present a new signal processing method for white-light interferometry which is fast, accurate, and extremely noise resistant. Theoretical results for the expected systematic and statistical errors will be compared with experimental results.

© 1992 Optical Society of America