Extending the Alvarez-Lens Concept to Arbitrary Optical Devices: Tunable Gratings, Lenses, and Spiral Phase Plates

The Alvarez lenses consist of two parts with surface geometry designed to produce a change in refractive power with transversal translation between the upper and lower parts of the device. In this study, we present a new and straightforward approach to calculating the geometry of such devices and show that an Alvarez configuration can be found not only for lenses, but also for virtually any refractive device. Surface profiles required to realize an optical wedge, a blazed grating, a lens, and a spiral phase plate are presented. The performance of the devices is verified by numerical simulations and experimentally.