Multifunctional all-dielectric metasurface quarter-wave plates for polarization conversion and wavefront shaping
Houjin He, Shiwei Tang, Ziwei Zheng, Fei Ding
Abstract
Different from conventional optical waveplates, which suffer from limited functionalities and bulky configurations, metasurfaces provide full-range birefringence control along with unprecedented capabilities of wavefront shaping at any wavelength range of interest with properly designed anisotropic meta-atoms, thereby resulting in miniaturized planar meta-waveplates with excellent and fancy functionalities beyond the conventional counterparts. In this Letter, we design a set of dielectric metasurface quarter-wave plates (QWPs) that enable efficient circular-to-linear polarization conversion along with complete phase control over the converted linearly polarized beam under circularly polarized (CP) excitation. Capitalizing on this meta-QWP platform, we numerically demonstrate two advanced multifunctional meta-QWPs (i.e., a beam-steerer and a focusing metalens) to generate different wavefronts with homogeneous and inhomogeneous linear polarization distributions under CP excitation, mimicking the functionalities of cascaded multi-stage optical components. Owing to the compactness, flexibility, and versatility, such meta-QWPs are capable of integrating more advanced applications in polarization optics.