A spin controlled wavefront shaping metasurface with low dispersion in visible frequencies†
Similar to amplitude and phase, optical spin plays an important and non-trivial role in optics, which has been widely demonstrated in wavefront engineering, creation of new optical components, and sensitive optical metrology. In this work, we propose and experimentally demonstrate a new type of spin controlled wavefront shaping metasurface. The proposed geometric phase metasurface is designed by employing the integrated and interleaved structures to independently control the left-handed and right-handed spin components. As an exemplary demonstration, our experimental results show that such a composite metasurface can convert a plane wave into a vortex beam and a Hermite beam for left-handed and right-handed polarized light, respectively. Because such a metasurface is made from non-resonant dielectric structures, it can work for broadband frequencies with very low dispersion. The proposed metasurface is fabricated by the laser writing method inside transparent glass with a low cost, which avoids the typical high-resolution lithography process. This spin dependent broadband wavefront shaping metasurface may find potential applications in optical communications, information processing, and optical metrology.