Zoom system by rotation of toroidal lenses

In a recent publication [Appl. Opt. 57, 8087 (2018).] a zoom system based on rotating toroidal lenses had been theoretically suggested. Here we demonstrate two different experimental realizations of such a system. The first consists of a set of four individually rotatable cylindrical lenses, and the second of four rotatable diffractive optical elements with phase structures corresponding to "saddle-lenses". It turns out that image aberrations produced by the refractive zoom system are considerably reduced by the diffractive system. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement