Displacement sensor with electronically scanned white-light interferometer

Absolute displacement sensing by white-light interferometry is demonstrated without mechanically moving parts in the receiving interferoineter. Its characteristics are: Michelson interferomneter with tilted mirrors, photodiode array of 1024 elements, lead-insensitivity up to 9 dB loss, displacement range 75 /.m, resolution 0.02 pm, read- out time < 7 ins, and multiplexing of several transducers.