Hologram Interferometry*†

The technique of wavefront reconstruction has made possible several basic extensions of interferometry. In the hologram interferometer it is not necessary that either beam be analytically expressible, nor is it necessary that the perturbances of the optical path be small. Moreover, it becomes possible to generate interferograms between wave disturbances which exist at different times, have different wavelengths, and/or have quadrature polarizations. We present a set of experiments which indicates the performance of the hologram recording system as an interferometer. The discussion of these extensions of classical interferometry with their applications is aided by reference to several independent developments of the hologram interferometry technique.