Monolithic 2-D scanning mirror using self-aligned angular vertical comb drives

We have demonstrated microfabricated, monolithic two degrees of freedom (two-dimensional) electrostatic torsional mirrors using a three-mask process on silicon-on-insulator wafer with a single plastic deformation step. The mirror operated independently in two orthogonal directions as controlled by two sets of self-aligned angular vertical combs. The measured dynamic performance showed resonant frequencies of 10.56 and 1.54 kHz with optical scanning angles up to 27 degrees and 20 degrees in the two orthogonal axes, respectively, under driving voltages of 20 V-dc plus 15 V-pp. A 90-day continuous mirror operation at peak resonance, in equivalent to 80 and 12.1 billion cycles on the two orthogonal axes, showed negligible performance variations.