Structured Light Generation Using Angle-Multiplexed Metasurfaces

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