Resonant Varifocal Mems Mirror

This paper presents a novel varifocal mirror made of a micro-electromechanical system (MEMS) continuous deformable mirror (DM). It uses resonant electrostatic actuation (REA) via single voltage waveform to vary the focus of a 1.6 mm circular DM. Unlike traditional DMs, REA eliminates the need for individually addressable electrodes and the use of complex influence functions. It also minimizes the electrode count, thereby providing for simpler and faster modulating DMs. The DM was integrated into an adaptive optics system as varifocal mirror. The system was able to realize an 8 cm focal shift between focal lengths of 11 cm and 19 cm by changing the phase angle between the DM drive signal and the pulse signal of the incident laser beam.