Efficient optomechanical mode-shape mapping of micromechanical devices

TL;DR

This paper introduces a rapid optical method using a modified phase-lock-loop to map multiple mechanical modes in micromechanical devices, providing detailed mode shapes and superposition analysis.

Contribution

A novel, fast, and robust optical mapping technique for multiple mechanical modes in micromechanical structures, validated on silicon nitride membranes.

Findings

Successfully mapped multiple modes simultaneously

Achieved high-quality mode shape resolution

Enabled analysis of superpositions of degenerate modes

Abstract

We demonstrate a method to optically map multiple modes of mechanical structures simultaneously. The fast and robust method, based on a modified phase-lock-loop, is demonstrated on a silicon nitride membrane and compared with three different approaches. Line traces and two-dimensional maps of different modes are acquired. The high quality enables us to determine the weights of individual contributions in superpositions of degenerate modes.