The intensity ratio alignment technique in photoelastic modulation ellipsometry and polarimetry

Abstract

The concept of intensity ratio alignment technique will be introduced by comparing it with the conventional null technique. For in situ/real time monitoring the plasma etching process, we will introduce a fixed incident angle alignment technique for a photoelastic modulation ellipsometer. In addition to ellipsometry, we will introduce a photoelastic modulation polarimetry to measure the twisted angle and phase retardation of a twisted nematic liquid.