DISPERSION IN STELLAR INTERFEROMETRY

The effects of uncompensated dispersion on the fringe visibility in a two beam interferometer are examined for a long baseline stellar interferometer with a path compensator in air rather than in vacuo. We derive a criterion based on the central fringe visibility for evaluating the effects of dispersion and develop a method for selecting suitable compensating media. By.limiting the optical bandwidth to -100 nm and using a compensating system with two glasses it is possible to achieve high fringe visibility in a stellar interferometer with excess air paths of the order of 500 m. The results are generally applicable to other two beam interferometers. © 1990 Optical Society of America.