A Tip-Tilt-Piston Micromirror With Symmetrical Lateral-Shift-Free Piezoelectric Actuators

In this paper, we present the design, fabrication, and characterization of a high-fill-factor tip-tilt-piston micromirror actuated by four symmetrical lateral-shift-free (LSF) piezoelectric actuators. Lead zirconate titanate (PZT) is the piezoelectric material deposited using a sol-gel process. The micromirror can operate in both piston and rotation modes. At the piston mode, the measured resonant frequency is 990 Hz. An 18.3-mu m piston displacement is obtained by applying 5 V-dc to four symmetrical LSF (SLSF) actuators. For the rotation mode, the measured resonant frequency is 1650 Hz and an optical deflection angle of 4.2 degrees is measured by applying 5 V-dc to one SLSF actuator. A 2-D resonant scanning pattern is achieved when the PZT micromirror is applied with a 3 V-pp sinusoidal voltage at the resonance frequency.