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.
William J. Tango, "Dispersion in stellar interferometry," Appl. Opt. 29, 516-521 (1990)