Structured Light Generation Using Angle-Multiplexed Metasurfaces

摘要

On the basis of the Jones matrix, independent control over the amplitude andphase of light has been demonstrated by combining several meta-atoms intothe supercell of a metasurface. However, due to the intrinsic limitation of aplanar achiral structure, the maximum number of independent, complexelements in one Jones matrix is three, giving rise to up to three-channelamplitude and phase control. In this work, more Jones matrices correspondingto different angles of incidence are proposed to add, so that the degrees offreedom in the amplitude and phase control can be further increased. Thesupercell of the designed metasurfaces consists of three dielectric nanoblockswith predefined rotation angles and displacements in the 2D space, which canbe inversely determined with the help of the genetic algorithm. Empowered bythe ability to realize four- or even eight-channel amplitude and phase control,the generation of multiple structured light, including two independent perfectPoincaré beams, two double-ring perfect Poincaré beams, two perfectPoincaré beam arrays, and four vector vortex beam arrays, is numericallydemonstrated. Such novel designs are expected to benefit the development ofmodern optical applications, including but not limited to opticalcommunications, quantum information, and signal encryption.