A comparison between two experimental techniques to characterize retardance as a function of applied voltage of liquid crystal variable retarders (LCVR) is presented. In the first method the variable retarder was rotated between two polarizers with their transmission axes parallel, and the retardance was calculated from the Fourier series coefficients for each applied voltage. The second method involved using two polarizers with their transmission axes perpendicular to each other, the variable retarder was placed between the polarizers with its optical axis at 45° from the horizontal, and a final stage known as "phase unwrapping" is used on experimental data to obtain the voltage-retardance function. With these two experimental methods, the voltage-retardance relationship was obtained. To verify the accuracy of this characterization a second experiment involving the production of specific polarization states was performed as the basis of a Mueller polarimeter. A method based on measuring the optical signal resulting from the application of a predetermined set of fixed values of retardance in each retarder was used. 16 elements of the Mueller matrix of a polarizer with its transmission axis at 0° and 90° were measured, and the results are compared to the expected theoretical values.

Date Published: 28 August 2016
PDF: 11 pages
Proc. SPIE 9960, Interferometry XVIII, 996014 (28 August 2016); doi: 10.1117/12.2237087

Published in SPIE Proceedings Vol. 9960:
Interferometry XVIII
Katherine Creath; Jan Burke; Armando Albertazzi Gonçalves Jr., Editor(s)