Flexible fabrication of large pixel count piston-tip-tilt mirror arrays for fast spatial light modulators

We present arrays of electrostatically actuated piston-tip-tilt micromirrors realized using a surface micromachining 3-structural-layer polysilicon process. High fill factor, flat mirrors 120@mm in size have mechanical response in the order of 10@ms, with +/-4^o mechanical tip and tilt and 5@mm piston continuous, controllable range under 110V. The actuator design is based on four dual in-plane comb drives with 0.5@mm critical feature size and high aspect ratio. We show a modular approach to fabricate these arrays, allowing multiple array sizes (64^2 and 256^2 mirrors) and four different designs to be implemented in three DUV masks per lithography level.