Efficient beam manipulation with Huygens-geometric metasurface supporting pure magnetic resonances

In this work, we propose the concept of Huygens-geometric metasurface by stimulating two magnetic dipoles with designated phases. A theoretical model is developed to reveal its physical mechanism, and the required conditions for zero-backward scattering are derived. We verify the model with an anisotropic all-dielectric meta-atom, which is composed of a thin silica layer sandwiched by two silicon nanofins. The meta-atom with a maximum conversion efficiency of 98.8% and robust against the variation of the structural parameters can be applied in high-efficiency transmitted beam manipulation, such as beam deflection and focusing. Our work paves the way for the development of high-performance functional meta-devices.