Title: High-transmissivity Silicon Visible-wavelength Metasurface Designs based on Truncated-cone Nanoantennae,
Abstract: High-transmissivity all-dielectric metasurfaces have recently attracted
attention towards the realization of ultra-compact optical devices and systems.
Silicon based metasurfaces, in particular, are highly promising considering the
possibility of monolithic integration with VLSI circuits. Realization of
silicon based metasurfaces operational in the visible wavelengths remains a
challenge. A numerical study of silicon metasurfaces based on stepped truncated
cone shaped nanoantenna elements is presented. Metasurfaces based on the
stepped conical geometry can be designed for operation in the 700nm to 800nm
wavelength window and achieve full cycle phase response (0 to pi with an
improved transmittance in comparison with previously reported cylindrical
geometry [1]. A systematic parameter study of the influence of various
geometrical parameters on the achievable amplitude and phase coverage is
reported.