Affiliation:
1. Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology
2. Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology
Abstract
Metasurfaces for wavefront shaping rely on local phase modulation in subwavelength unit cells, which show limited degree of freedom in dealing with complex and multiple beam transformation. Here, we assign multiple beams into different diffraction orders coaxially located along the same direction, whose wavefronts are tailored by optimizing the diffraction coefficients in two orders and two polarization states of a supercell. By evenly splitting the energy into two orders and adjusting the zeroth-order diffraction phase, a Bessel beam and a vortex beam are simultaneously generated in the near field and far field along a coaxial direction. The effectiveness of the method is validated by the excellent agreement between the simulation and experimental characterization of the two beams.
Funder
National Key Research and Development Program of China
National Natural Science Foundation of China
Subject
Atomic and Molecular Physics, and Optics