Abstract: An interferometer comprises a non-uniform beam splitter (34) which splits an incoming beam (30) of energy into two beams (36, 38). The two beams (36, 38) are taken from parts of the incoming beam (30) which overlap. The two beams (36, 38) are fed spacially separated energy feeds (44, 46) and then fed to a comparator to produce sum and difference channels (54, 58). The sum and difference channels (54, 58) are guided to a means for detecting a difference in phase (60) between the sum and difference channels (54, 58).

Abstract: An interferometer having a light beam source that produces a plurality of separate and distinct wavelengths of light. Optic fibers are used to transport the wavelengths of light toward an object surface and to allow light reflected from the object to pass through a polarizer to improve the polarization ratio of the reflected light to determine a characteristic of the object surface.

Abstract: An interferometer device includes a first prism portion and a second prism portion. The first prism portion has a semi-transparent surface, a beam incident surface and a beam emerging surface. The beam incident surface receives an incident light beam at a wavelength of &lgr; and at an angle of incidence &thgr; with respect to a normal to the beam incident surface. The second prism portion has a surface that corresponds to the semi-transparent surface of the first prism portion and a beam emerging surface that corresponds to the beam emerging surface of the first prism portion. The first and second prism portions are attached to each other at the semi-transparent surface of the first prism portion and the surface of the second prism portion corresponding to the semi-transparent surface.