3C04 Converting Fixed Focus Lens to Variable-Focus Lens Using Liquid Crystal Layers

Abstract

A variable-focus lens composed of a glass lens and liquid crystal layers is proposed. The variance of thickness of the glass lens makes a nonuniform electric field distribute in the liquid crystal layers, and directors' rotation in the central region is smaller than that near the aperture boundary. Thus, a bell-like distribution of the refractive index for an incident extraordinary ray (e-ray) is formed. The phase retardation experienced by the e-ray may take a nearly quadratic form that can be varied by the external voltage, and the system behaves as an electrically tunable variable-focus lens.