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° and 20° 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.