Monolithic high aspect ratio two-axis optical scanners in SOI

Fully monolithic silicon optical scanners are demonstrated with large static optical beam deflection in two axes. The main advantage of the scanners is their high frequency of operation for both axes. Namely, the actuators allow static two-axis rotation of a micromirror without the need for gimbals, or specialized isolation technologies. Each device is actuated by four orthogonally-arranged vertical combdrive rotators etched in the device layer of an SOI wafer, which are coupled by mechanical linkages and mechanical rotation transformers. The transformers allow larger static rotations of the micromirror from the combdrive-stroke limited rotation of the actuators; with a magnification of 1.7x angle demonstrated. A device with a mirror diameter of 600 mum exhibits lowest resonant frequencies of 4.9 kHz and 6.52 kHz for x-axis and y-axis,. respectively. The static optical deflection of the x-axis up to 9.6degrees and of the y-axis up to 7.2degrees, are achieved for <275 Vdc. Another type of device, designed for lower-voltage operation exhibits static optical deflection about the x-axis to 10.8degrees and about the y-axis to 11.7degrees, for <85 Vdc. In the same device, lowest resonant frequencies were 1.69 kHz for the x-axis and 2.43 kHz for the y-axis.