title: A facile grating approach towards broadband, wide-angle and high-efficiency holographic metasurfaces.
abstract: We analytically show that an incident light can be almost completely diffracted into the -1(st) order in wide-angle and broadband by suitably designed thin metallic nano-gratings with simple rectangular cross sections. Such extraordinary optical diffraction results from the excitation of localized cavity modes and exists even when the grating period is modulated in a broad range. By modulating the period with binary holography techniques, we can shape an incident wave into arbitrary wavefronts with near-unity conversion efficiencies. To show the efficacy of this approach, we demonstrate three reflection-type metasurfaces for achieving near-complete conversions from a Gaussian beam into a focused beam, Bessel beam, and vortex beam, respectively, with the complete suppression of the undesired specular reflection. Our findings provide a facile approach to build arbitrary wavefront-shaping metasurfaces with wide-angle, broadband, and high efficiency performance.
authors.affiliation: College of Electronic Science and Technology and Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China. gpwang@szu.edu.cn.
authors.forename: Zi-Lan
authors.initials: ZL
authors.lastname: Deng
authors.affiliation: School of Physics & Astronomy, University of Birmingham, Birmingham B15 2TT, UK.
authors.forename: Shuang
authors.initials: S
authors.lastname: Zhang
authors.affiliation: College of Electronic Science and Technology and Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China. gpwang@szu.edu.cn.
authors.forename: Guo Ping
authors.initials: GP
authors.lastname: Wang