Amazing scatterplate interferometer

Abstract

The scatterplate interferometer is an amazing instrument invented by James M. Burch in 1953 for testing optical components and it is especially good for testing concave mirrors. This interferometer requires no high-quality optical components and it generates its own reference wavefront without having a reference surface. The light source does not have to be a point source or monochromatic - almost any light source will work. The path lengths of the two interferometer paths are automatically matched and, regardless of the reflectance of the test mirror, the light intensities of the two interfering beams are matched. The interferometer is not very sensitive to vibration and it is inexpensive to build. There are several ways to use phase-shifting techniques with the interferometer. This talk will describe and explain the properties of the amazing scatterplate interferometer.