Creation of aspheric interfaces on an electrowetting liquid lens using surface oscillations

A technique to create aspheric surface shapes on commercially available electrowetting liquid lenses is demonstrated. Based on a previously published surface oscillation model a technique using a Hankel transform is proposed and tested experimentally. An alternating actuation voltage is applied to the liquid lens to stimulate surface oscillations, that temporarily add up to the desired surface shape. The voltage signal can be repeated at video rate. The measurements were taken with a Mach-Zehnder interferometer and confirm the previous results. The capabilities and limitations of the proposed method are demonstrated using the examples of a Bessel surface, spherical aberration, an axicon, and a top hat structure.