Sub-100 μs Settling Time and Low Voltage Operation for Gimbal-less Two-Axis Scanners

We demonstrate high speed point-to-point laser scanning with gimbal-less two-axis micromirror scanners that were previously demonstrated [1],[2]. We apply and compare several different open-loop and closed-loop control techniques on monolithic single-crystal silicon micromirrors of 0.6 mm diameter and on a high fill-factor tip-tilt-piston device of 0.8x0.8 mm. Both in open-loop and closedloop methodology very broadband operation beyond the first resonance is possible which results in very fast settling times. The fastest open-loop result of 96 μs settling time (from 2° to within 1% of final value of 4° of scan angle) was obtained by combining an “inverse transfer function” filter and a square root function. Fastest closed-loop settling-time with optical feedback and PD control was 92 μs. Furthermore, we utilize a simple and robust methodology for low-voltage (<1V rms) operation of the scanner system and demonstrate various vector display examples by driving such systems from a laptop’s audio port.