PRELIMINARY EXPLORATION OF EXPERIMENTAL MECHANICS DIAGNOSTICS BASED ON METALENS

Metalenses, as emerging planar nanophotonic elements, offer remarkable advantages, including ultrathin and lightweight properties, along with highly flexible control over incident light. These characteristics position metalenses as promising alternatives to traditional optical lenses. While current research on metalenses primarily focuses on enhancing optical performance and iterating metamaterials, with limited exploration into their application in conventional mechanical testing fields. Moreover, the potential of metalenses in advanced optical diagnostic techniques remains largely unexplored. This paper introduces a novel Particle Image Velocimetry (Meta-PIV) and Digital Image Correlation (Meta-DIC) technique based on a custom-designed binocular metalens. The results demonstrate that the proposed binocular Meta-PIV system, validated through a vortex ring experiment at a Reynolds number of 2000, is capable of measuring a 2D-3C velocity field and offers time-resolved flow analysis. The measurement error for the vortex ring diameter is approximately 1.25%. Additionally, the Meta-DIC system, based on binocular metalenses, allows for accurate measurement of displacement and strain fields in the X, Y, and Z directions, with measurement errors below 10% compared to conventional Stereo-DIC systems, and less than 1% error in the Y direction. This research aims to provide new insights into the potential application of metalenses in mechanical testing and offers valuable reference data for future developments in this field.