Evaluation of the electro-optic response of reflective liquid crystal cell

The electro-optic properties of the reflected light in a reflective mode, 45°-twisted nematic liquid crystal (TNLC) cell were investigated in the voltage regions near and away from the Freedericksz transition threshold. The measured reflectivity away from the threshold voltage (Vth) could not be described by the model which assumes a constant tilt angle as well as a linearized distribution of twist angle across the cell, although the data are well fitted near Vth. We found that in the voltage region away from Vth, the model considering the distributions of the tilt angle and the twist angle should be applied for the calculation of the reflectivity. The director-axis distributions were obtained from the numerical integration of the Euler–Lagrange equation.