Tunable electro-optic microlens array. I. Planar geometry

A description is given of a microlens array design, believed to be new, wit h tunable focal length. Converging or diverging periodic refractive-index d istribution is induced in a linear electro-optic wafer through the applicat ion of electric field profiles on both sides of the wafer. The transparent electrodes on both sides of the wafer are positioned such that the electrod es on the opposite side compensate the phase delay from the electrodes on t he front side of the wafer for a normally incident plane wave, suppressing the intrinsic electrode diffraction for the device without applied voltage. The original technique of the electric field calculation was developed to analyze accurately the induced refractive index inside the wafer. Its focal length changes from 7 mm to infinity at a 1-mu m wavelength with an extern al voltage range of 0-100 V. (C) 2000 Optical Society of America. OCIS code s: 120.5710, 060.5060, 110.2760, 160.2100, 130.3120.