title: Formation of negative-index-change waveguide lenses in LiNbO(3) by using ion milling.
abstract: We report, for the first time to our knowledge, fabrication of two types of negative-index-change waveguide lens in LiNbO(3) by using ion milling. The first type is an analog Fresnel lens formed by grooves milled into the waveguide. The second is a hybrid lens that combines analog Fresnel zones in the central region with chirp gratings on the sides formed by the same means. We have obtained simultaneously high-efficiency and near-diffraction-limited focusing characteristics in both types of lens. The ion-milling technique employed should be capable of producing similar lenses in any other waveguide substrate, such as GaAs.
authors.forename: T Q
authors.initials: TQ
authors.lastname: Vu
authors.forename: J A
authors.initials: JA
authors.lastname: Norris
authors.forename: C S
authors.initials: CS
authors.lastname: Tsai