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.