A New Class of Varifocal Lenses

In an ordinary varifocal or zoom lens system one or more lenses are moved back and forth along the optical axis. But lateral movements can also cause a zoom effect. The refractive or diffractive elements to be moved are no longer rotationally symmetrical. The elements can be made out of transparent material or as a grating with curved lines or as a special version of a kinoform. The zoom systems with lateral motion are very compact.