Low-coherence light interferometry, instrumentation design, and application development

A high-resolution (sub micron accuracy) fiber optic coupled dual Michelson interferometer based instrument has been developed and is being utilized in a variety of process monitoring applications. The instrument includes both coherent and non-coherent light sources, custom application dependent optical probes and sample interfaces, a Michelson interferometer, custom electronics, a Pentium based PC with data acquisition cards and LabWindows CVI based application specific software. This paper describes the development of this instrument with special emphasis on applications development. The principles behind robust instrument design hardware, software and user interfaces are discussed.