In interference microscopes requiring oblique incidence illumination (i.e., Michelson, Mirau, and Linnik), the fringe spacing varies with illumination numerical aperture so that calibration is needed for accurate measurements.
© 1989 Optical Society of America
Original Manuscript: April 17, 1989
Published: June 1, 1989
James F. Biegen, "Calibration requirements for Mirau and Linnik microscope interferometers," Appl. Opt. 28, 1972-1974 (1989)