An efficient device using a transparent grooved screen and three detector channels is described for measuring the complex coherence factor between two optical beams. The device statically provides both in-phase and quadrature fringe components, the same signals as are customarily available in radio interferometry. The deleterious effects of a nonaplanatism in stellar interferometry are described along with a novel configuration for interferometrically combining two telescopes to provide simultaneously fringes anywhere in the field of view with the goal of optical aperture synthesis. Complex fringe detection also has certain applications in spectral interferometry, and a suitable interferometer with achromatized throughput is described. That interferometer may also be used for distance or thickness measurement.
© 1983 Optical Society of America
Lawrence Mertz, "Complex interferometry," Appl. Opt. 22, 1530-1534 (1983)