ABSTRACT
Interferometry employs the ability of two beams of electromagnetic radiation to interfere with one another provided certain criteria of coherence are achieved. The technique can be used to sense, very accurately, disturbances in one of the beams provided the other beam’s properties are accurately known. There are many variants of interferometers but this chapter discusses the application of interferometers to the testing of optical components and systems, and is restricted to the commonest types of interferometers commercially available.
