Infrared Spectropolarimetry
Abstract
A new instrument, a Fourier transform infrared (FTIR) spectropolarimeter, has been developed to characterize the elements of polarization critical optical systems. The rotating sample spectropolarimeter measures linear diattenuation (polarization) and linear retardance spectra of samples over a spectral range from 2.5 to 20 mum. The dual rotating retarder spectropolarimeter measures Mueller matrix spectra from 3 to 14 mum. This information provides essential data on the wavelength response of polarization elements and the modulation characteristics of spatial light modulators as a function of wavelength. This dissertation describes data reduction algorithms for the rotating sample and dual rotating retarder polarimeters. The discussion includes description of common sources of systematic errors in polarimetric systems and how many of these errors are reduced or removed through the choice of appropriate measurement parameters and Fourier analysis of the polarimetric signal. The data reduction algorithms for spectropolarimetric measurements incorporate the wavelength dependence of the polarization elements. Self-calibration data reduction methods are also described. Linear diattenuation, linear retardance, and linear birefringence spectra of cadmium sulfide and cadmium selenide multiple order waveplates and three liquid crystal materials are presented. Linear diattenuation and linear retardance calibration spectra of the polarization elements used in the spectropolarimeter, and infrared wire grid polarizer on a zinc selenide substrate and an infrared achromatic quarter wave retarder, are also given. Mueller matrix spectra of a cadmium telluride modulator are given as a function of voltage. The electro-optic coefficient spectrum of cadmium telluride calculated from the Mueller matrix spectra is presented.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1992
- Bibcode:
- 1992PhDT.......216C
- Keywords:
-
- POLARIZATION CRITICAL OPTICAL SYSTEMS;
- Physics: Optics