Gimbal-less monolithic silicon actuators for tip-tilt-piston micromirror applications

In this paper, fully monolithic silicon optical scanners are demonstrated with large static optical beam deflection. The main advantage of the scanners is their high speed of operation for both axes: namely, the actuators allow static two-axis rotation in addition to pistoning of a micromirror without the need for gimbals or specialized isolation technologies. The basic device is actuated by four orthogonally arranged vertical comb-drive rotators etched in the device layer of an silicon-on-insulator wafer, which are coupled by mechanical linkages and mechanical rotation transformers to a central micromirror. The transformers allow larger static rotations of the micromirror from the comb-drive stroke limited rotation of the actuators, with a magnification of up to 3/spl times/ angle demonstrated. A variety of one-axis and two-axis devices have been successfully fabricated and tested, in all cases with 600-/spl mu/m-diameter micromirrors. One-axis micromirrors achieve static optical beam deflections of >20/spl deg/ and peak-to-peak resonant scanning of >50/spl deg/ in one example at a resonant frequency of 4447 Hz. Many two-axis devices utilizing four rotators were tested, and exhibit >18/spl deg/ of static optical deflection at