Better 3D inspection with structured illumination: signal formation and precision

Abstract

3D metrology faces increasing demands for higher precision and larger space-bandwidth-speed product (number of 3D points/s). In this paper we consider structured-illumination microscopy as a means for satisfying these demands, developing a theoretical model of the signal formation for both optically smooth and optically rough surfaces. The model allows us to investigate physical limits on precision and to establish rules that allow sensor parameter optimization for greatest precision or highest speed.