Characterization of a micromechanical spatial light modulator

Abstract

The optical-beam-control dynamics of torsion-beam deformable-mirror-device spatial light modulators has been characterized to determine properties important to their operation. The responses of individual picture elements to steady-state, transient, and harmonic excitation were measured using optical-beam-deflection sensors. The steady-state angular deflection is characterized by a stable, reversible regime for applied voltages less than a critical value, Vc (∼16 VDC), an unstable transition to stable maximal deflection at Vc, and hysteresis as the applied voltage is reduced to zero. Representative devices with 50 μm×50 μm pixels exhibit full-deflection rise times of tens of microseconds and small-deflection resonant frequencies of the order of 10 kHz.