Methods and apparatus for focus improvement in multiple liquid crystal cell lenses

Abstract

A liquid crystal optical device is provided including at least two LC cells. A first LC cell layer has a predominant director orientation imparting a transversally non-uniform phase delay to a first polarization of an unpolarized incident light field passing therethrough while incident light of a second polarization orthogonal to the first light polarization passes therethrough undergoing transversally uniform phase delay. The first LC cell is configured to project a center extraordinary ray onto an optical axis of the device at the image surface. A second LC cell layer has a predominant director oriented orthogonally to the other predominant director in a plane perpendicular to the optical axis. The second LC layer imparts a transversally non-uniform phase delay to the second polarization of the incident light passing therethrough, the second LC cell being configured to project a center ordinary ray onto the optical axis at the image surface.