Active metasurfaces for spatial light modulation

我们提出在半导体或导电氧化物上的等离子体纳米结构作为用于控制反射或透射光的相位的有源元件-相移像素。这些元件可以排列成阵列以形成反射（或透射）超颖表面，从而实现波前整形和切换应用。** 元件将由共振金属纳米结构形成，该共振金属纳米结构被定制为将宽边入射光耦合到在其上传播的 ** 表面等离子体激元（SPP），从而影响它们的散射特性。SPP相对于入射光具有 ** 显著增强的场（10到100倍），导致增强的光-物质 ** 相互作用，并导致增强的相移或吸收，以及增强的非线性过程。此外，金属超颖表面可以电接触，使得该表面可以同时用作器件电极以施加电压或供应电流，从而确保SPP与下层材料的有源区具有强的重叠。这些特性将被用来生产用于电信应用的紧凑型固态移相器和空间光调制器。

We propose plasmonic nanostructures on a semiconductor or conductive oxide as active elements for**controlling the phase of reflected or transmitted light - phase-shifting pixels. Such elements can be arrayed to**form a reflective (or transmissive) metasurface that enables wavefront shaping and switching applications. The**elements will be formed of resonant metallic nanostructures tailored to couple broadside-incident light to**surface plasmon-polaritons (SPPs) propagating thereon thus affecting their scattering properties. SPPs have**significantly enhanced fields relative to the incident light (10 to 100×), resulting in enhanced light-matter**interaction and leading to enhanced phase shifts or absorption, and to enhanced nonlinear processes.**Furthermore, a metallic metasurface can be contacted electrically such that the surface can simultaneously be**used as a device electrode to apply voltages or supply currents, thereby ensuring that SPPs have a strong**overlap with the active region of the underlying material. These attributes will be exploited to produce compact**solid-state phase shifters and spatial light modulators for telecommunications applications.