2022/02/24 by Wenlong Gao, Gao, Wenlong, Basudeb Sain +3
Materials Science · Engineering · Physics and Astronomy · #Metamaterials and Metasurfaces Applications #Plasmonic and Surface Plasmon Research #Orbital Angular Momentum in Optics
paper · pdf · doi:10.48550/arxiv.2202.11980
We study the negative couplings amid local resonances of photonic metasurfaces. In our analysis, we discover pseudo-spin-orbit coupled bulk modes leading to lines of circularly polarized radiation eigenstates in two-dimensional momentum space which were considered to exist only in three-dimensions. Our theoretical model is exemplified via a guided resonance dielectric metasurface that possesses Type-II Non-Hermitian diabolical points, from where the circular polarization lines emanate. The designed metasurface carries circular polarized radiation eigenstates in both the 0th and the 1st diffraction orders, allowing spin-selective light deflections. The high quality factor nature and field enhancement of the designed metasurface could lead to applications for spin-selective sensing, beam control and nonlinear optics. Our findings open a gateway for the design of near-field couplings assisted metasurfaces.