Optimum Wavelength Selection to Extend the Unambiguous Measurement Range of the Three-wavelength Single-shot Interferometry

Abstract

This paper presents a novel method for selecting optimum measurement wavelengths in multi-wavelength interferometry. It is based on a coincidence error analysis in exact fractions solutions. By this method, three wavelengths of 470, 560, and 600nm have been selected. With these wavelengths, a surface profiler has been developed using three-wavelength single-shot interferometry, and an extended measurement range over 8µm has been experimentally proved.