Freeform high-speed large-amplitude deformable piezo mirrors

We present a new type of tunable mirror with sharply-featured freeform displacement profiles, large displacements of several 100μm and high operating frequencies close to the kHz range at 15mm diameter. The actuation principle is based on a recently explored “topological” displacement mode of piezo sheets. The prototypes presented here include a rotationally symmetric axicon, a hyperbolic sech-icon and a non-symmetric pyram-icon and are scalable to smaller dimensions. The fabrication process is economic and cleanroom-free, and the optical quality is sufficient to demonstrate the diffraction patterns of the optical elements.