Optical displacement sensing system utilizing edge diffraction
Methods are provided for determining the position of a substrate. The edge diffraction model suitable for the proposed measurement apparatus was mathematically derived, and the effect of the parameters associated with the edge diffraction was investigated. In addition, the fundamental limits are discussed about the linearity and resolution of the sensor by estimating the effects of edge roughness and sharpness of the knife edge on the knife edge diffraction of an incident wave based on Kirchhoff approximation.
author list (cited authors)
Tarbutton, J., & Lee, C. B.