Optical-phase-difference properties on a large aperture liquid-crystal lens with Fresnel-lens type refractive index properties.

Abstract

We propose a liquid crystal (LC) lens with an electrically tunable Fresnel lens-type refractive index distribution. The LC lens is prepared using a glass substrate with transparent circular-electrode and ring-patterned electrodes of different widths. Both negative and positive lens properties of smoothly parabolic optical-phase-retardation can be realized by applying appropriate voltages across the patterned electrodes and common flat electrode. The lens properties can be tuned with preserving the good optical quality over the entire focal range.