Fast Tracking of Light Source with Micromirror and Associated Feedback Circuit

In this paper, a closed-loop feedback control of a micromirror has been demonstrated to track a moving light source and to stabilize fast the tilting angle to follow the light source. An electrostatically actuated torsional micromirror was used as a test device. Tracking and tilt-angle stabilization has been tested using a position-sensing detector and analog feedback control circuit. We found a successful tracking of a moving light source and the feedback control to improve the response time of micromirrors significantly, down to 200 mus in comparison to about 600 mus for the case of absence of feedback control.