Dielectric metalens-based Hartmann–Shack array for a high-efficiency optical multiparameter detection system

The real-time measurement of the polarization and phase information of light is very important and desirable in optics. Metasurfaces can be used to achieve flexible wavefront control and can therefore be used to replace traditional optical elements to produce a highly integrated and extremely compact optical system. Here, we propose an efficient and compact optical multiparameter detection system based on a Hartmann–Shack array with 2×2 subarray metalenses. This system not only enables the efficient and accurate measurement of the spatial polarization profiles of optical beams via the inspection of foci amplitudes, but also measures the phase and phase-gradient profiles by analyzing foci displacements. In this work, details of the design of the elliptical silicon pillars for the metalens are described, and we achieve a high average focusing efficiency of 48% and a high spatial resolution. The performance of the system is validated by the experimental measurement of 22 scalar polarized beams, an azimuthally polarized beam, a radially polarized beam, and a vortex beam. The experimental results are in good agreement with theoretical predictions.