Generation of Spin-Dependent Accelerating Beam with Geometric Metasurface

Airy beam holds great promise for wide applications because of its unique features of being diffraction-free, self-accelerating, and self-healing. Much efforts are devoted to develop concise and efficient methods to generate and manipulate accelerating Airy beams. In this paper, a novel method is proposed to generate single or paired Airy beams by encoding the geometric phase of dielectric metasurface. Cubic phase, together with a linearly gradient phase, is imposed on the metasurface to control the acceleration and initial launching velocity of accelerating Airy beams. Spin-dependent geometric phase facilitates the generation of spin-dependent Airy beams by simply controlling the polarization of incident light. High quality of the generated Airy beam is testified by characterization of its diffraction-free, self-accelerating, and self-healing propagation. Despite the loss for silicon in visible region, generation efficiency as high as 63% is achieved for the metasurface Airy beam generator. The results demonstrate the possibility to manipulate complex structured optical field with all-dielectric metasurface and broaden the potential application of Airy beams into compact and integrated systems.