The design of a Fresnel lens with continuous focal length is proposed for use in optical processing. A convex lens is induced in lanthanum-modified lead zirconate titanate through the application of an electric-field profile supplied by the indium tin oxide electrodes that make up the zones of a Fresnel lens. The use of a numerical method based on fast Fourier transform algorithms was required to analyze accurately the induced field inside a Fresnel lens with an initial focal length of 0.4 m (at 470 nm) and 20 indium tin oxide electrodes. The effective focal location obtained by the combined mechanisms is derived. This design is expected to produce continuous variations of ~16% in focal length; the ability of previous designs to achieve focal length switching is maintained.
© 1995 Optical Society of America
Original Manuscript: June 13, 1994
Revised Manuscript: August 29, 1994
Published: May 1, 1995
Francisco Castro and Bahram Nabet, "Design of a dual-effect lens on lanthanum-modified lead zirconate titanate for continuous variation of focal length," Appl. Opt. 34, 2317-2323 (1995)