Highly accurate spectral retardance characterization of a liquid crystal retarder including Fabry-Perot interference effects

Highly accurate spectral retardance characterization of a liquid crystal retarder including Fabry-Perot interference effects January 2014

A Vargas, M del Mar Sánchez-López… – Journal of Applied Physics, J. Appl. Phys. 115, 033101 (2014)
Multiple-beam Fabry-Perot (FP) interferences occur in liquid crystal retarders (LCR) devoid of an antireflective coating. In this work, a highly accurate method to obtain the spectral retardance of such devices is presented. On the basis of a simple model of the LCR that includes FP effects and by using a voltage transfer function, we show how the FP features in the transmissionspectrum can be used to accurately retrieve the ordinary and extraordinary spectral phase delays, and the voltage dependence of the latter. As a consequence, the modulationcharacteristics of the device are fully determined with high accuracy by means of a few off-state physical parameters which are wavelength-dependent, and a single voltage transfer function that is valid within the spectral range of characterization…. 21 A visible spectrometer (Stellar-Net, model EPP2000) was used to analyze the transmission of the device in different cases. The LCR was illuminated by the continuous broadband light spectrum of a tungsten lamp (Stellar Net SL1).