Chirality control with dielectric metasurfaces

Polarization is a property of light that is fundamental to light-matter interactions and gives rise to various phenomena that are useful in communication technology, biological sensing, and holography. Dielectric metasurfaces, which are 1- or 2-D structural arrays of subwavelength periodicity, are a low-loss method of controlling light amplitude, phase, and polarization. One drawback of metasurfaces is that they are not generally reconfigurable; each is designed to impart a certain change to the incident light, and if different output is required a new device must be designed and fabricated. Here, the authors demonstrate a chiral metasurface with record-high circular dichroism and discuss the plausibility of using optical pumping to achieve reconfigurability on a single metasurface.