Optimized design and experimental study of a macroscopic mirror to achieve linear amplification of optical force-induced displacement

Abstract

A new thin plane mirror with an Archimedes spiral structure (Archimedes-structure thin plane mirror - ATPM) that implements an elastic support boundary is proposed in this study. An optimal structure of ATPM is developed to achieve a linear displacement response with respect to optical forces. The displacement response of the optimized ATPM is analyzed by considering the combined effects of optical force and gravity. The distribution of the optical force density is calculated based on a tilted Gaussian laser beam. Experimental results demonstrate that the optimized ATPM can produce a steady-state displacement of 24.18 nm on average in a normal-gravity environment when subjected to an average optical force of 132.17 nN. When the optical force exceeds 133 nN, the nonlinearity of the displacement response of the optimized ATPM is less than 6.28%. An amplification of the optical force-induced displacement is achieved by more than 15 times compared with that for an unstructured mirror of the same size. The results of this study can assist the development of a miniaturized macroscale optical force platform based on an ATPM for practical applications including the in-situ laser power measurement and nN level force source in the atomic and close-to-atomic scale manufacturing.