Fig. 3. Methods to control abrupt phase imposed by meta-atoms.

a Field distributions for electric and magnetic dipoles. b Amplitude and phase modulation by adjusting the dimensions of resonant meta-atoms. Panels a and b are reproduced with permission²². Copyright 2015, Wiley-VCH. c The normalized magnetic field indicating a waveguide mode. Reproduced with permission⁴⁶. Copyright 2018, American Physical Society. d Comparison of the phase calculated by FDTD simulation of nanopillar on a glass substrate, and the phase due to propagation in an isolated cylindrical waveguide. Reproduced with permission³⁵. Copyright 2016, American Chemical Society. e Schematic of the geometric phase in Poincaré sphere. f Geometric phase generated by rotating the orientation of anisotropic meta-atoms (blue) and the corresponding conversion efficiency of the incident circular polarization (red). Reproduced with permission³⁴. Copyright 2017, American Chemical Society