A silicon micromechanical galvanometric scanner

The design, fabrication, characterization and modeling of a micromechanical optical scanner driven electromagnetically is described. This microscanner, based on the galvanometric principle, consists of a thin film mirror surrounded by a planar coil deposited on a Si base that is able to rotate around suspended torsion bars and all is immersed in an external magnetic field. This design has no transverse force acting on the rotation axis during scanning, which provides good mechanical characteristics as low distortion and damping, high optical angular deflection (greater than or equal to 22 degrees peak-to-peak) and large Q quality factor at the resonant frequency. Variations in the design are presented and shown to enhance the deflection angle, the speed response and decrease the power consumption. (C) 1999 Elsevier Science S.A. All rights reserved.