This paper describes an optical surface profiling system based on phase quadrature differential interferometry. The optical path difference between two adjacent optical probe beams is measured. Interference phase calculation and sample scanning is controlled by a PC computer. Height sensitivity is of the order of 1 nm and lateral resolution is ~10 µm. Results are given which demonstrate the reproducibility and stability of the system.
© 1990 Optical Society of America
Basil A. Omar, Alan J. Holloway, and David C. Emmony, "Differential phase quadrature surface profiling interferometer," Appl. Opt. 29, 4715-4719 (1990)