Generating Steep Phase Anisotropy With Zero-Backscattering By Arrays of Coupled High Permittivity Dielectric Nanoresonators

Simultaneous excitation of electric and magnetic dipolar modes in high-permittivity dielectric nano-resonators can lead to zero-backscattering, i.e. full transmission. Here, we numerically demonstrate that stable or unstable zero-backscattering by 2-dimensional (2D) arrays of Si nano-resonators can be realized. We also show that this Si nano-resonator array with anisotropic periodicity can generate approximate 2$\pi $ optical phase anisotropy for the transmitted light at the wavelength of zero-backscattering. By introducing strong Fano-type coupling into unit cells of the array, ultra-steep phase anisotropy can be achieved. These special optical properties promise applications in various transmissive photonic devices, and we show their potential applications in transmissive polarization conversion and sensing.