Investigation on the three-dimensional light intensity distribution of the fringe patterns generated by a modified two-axis Lloyd's mirror interferometer

Abstract

This paper presents a design study of an optical configuration for the fabrication of a two-dimensional grating, which will be used as a scale in a planar encoder system. For the modified two-axis Lloyd's mirror interferometer, in which major modifications have been made to the conventional one-axis Lloyd's mirror interferometer, computer simulation is carried out based on wave optics. Three-dimensional light intensity distributions of the fringe patterns are calculated to investigate the effect of the polarization modulation. In addition, a relationship between the asymmetry of the cross-sectional profiles of the grating pattern structures and the designed grating pattern period is also investigated. Furthermore, pattern exposure tests have been carried out by using a prototype optical setup for the modified two-axis Lloyd's mirror interferometer.