Varifocal Micromirror Integrated With Comb-Drive Scanner on Silicon-on-Insulator Wafer

We present a varifocal scanning micromirror fabricated from a silicon-on-insulator wafer. The varifocal scanning micromirror consists of a varifocal mirror with a rotational scanning function. The scanner and varifocal mirror are driven by comb and parallel-plate electrostatic actuators, respectively. The mirror rotates 5.5° at 45 V in static mode. The curvature of the varifocal mirror is changed from -4 m^-1 (-128-mm focal length) to +5 m^-1 (+93-mm focal length) by applying a voltage from 0 to 50 V. It is confirmed that the lateral position and spot size of the reflected laser beam from the varifocal scanning micromirror are changed simultaneously. Moreover, confocal sensing is demonstrated using a fiber-optic system with the proposed mirror.