Driving liquid crystal lens without LC molecular orientation defects induced by an electric field

Abstract

Using the finite element method, we numerically investigated the transient behavior of molecular orientations of a liquid crystal (LC) lens with a circular electrode beside a hole-patterned electrode and a common flat electrode that has a resistive film. The transient properties of a three-dimensional electric field and the molecular orientations of the LC were simultaneously calculated when voltages were applied across a circular electrode/circularly hole-patterned electrode and a common electrode. The axially symmetric and bell-like distribution of the refractive index could also be obtained. When relatively high voltages were applied to the LC lens, LC molecular orientation defects, such as the disclination line, occurred in the inner region of the circularly hole-patterned electrode. The behavior of the LC directors at the defects were estimated, and transient properties of their phase profiles were predicted via numerical calculation. The spherical distribution of phase retardation without defects could be exhibited by applying a relatively high voltage with short switching on and switching off.