Spectrally controlled source for interferometric measurements of multiple surface cavities

Abstract

We present a new light source capable of locating interference fringes at an adjustable distance from the interferometer. The spectrum is electronically controlled in such a way that the fringes are limited to only one of the surfaces of the optics under test. With the new source it is straightforward, for example, to measure the parallel surfaces of thin glass plates and multiple surface cavities. Existing interferometers, as well as older systems, can be upgraded with this source.