Electro-optical response of the combination of two twisted nematic liquid crystal cells in series and the applicability of the extended Jones matrix

Abstract

A typical electro-optical response is observed by connecting two twisted nematic liquid crystal cells in series and placed back to back such that the director orientation on the back glass substrate of the first cell coincides with the director orientation of the front glass substrate of the second cell and vice versa. The two cells connected in series show cholesteric rotation. It is observed that for a given frequency the output transmittance oscillates having distinct maxima and minima with varying voltage and no flickering of transmittance have been observed at low frequencies. Variation of transmittance with frequency for given voltages is also reported and it has been found that increase of voltage at high frequency does not alter the transmittance appreciably. A discussion on the extended Jones matrix formulation and the scope of its applicability for this case is also given.