Reliability evaluation of MEMS scanning mirrors with an embedded mirror-monitoring sensor under external random vibrations

Abstract

We propose a quantitative metric, the Index of Vibration Influence (IVI), to assess how external random vibrations affect resonant MEMS scanning mirrors that embed a mirror-angle sensor. The setup excites the mirror with PSD-specified random profiles while the mirror is driven near its resonant frequency. The IVIo, which quantifies vibration-induced scan-angle perturbations, is defined at the operating frequency (f(o)), as the ratio of the mirror-angle spectra influenced by external vibration to those without random vibration. We validate the linearity error of the embedded sensor as small as 1.25% compared with an external PSM. Using the validated sensor, IVIo was evaluated at - 45 dB, corresponding to 0.17 degrees angle perturbations at 30.18 degrees OSA, when random vibration was applied at an acceleration level 30% higher in RMS than the IEC 62,498-3 requirement.