Flat optics: Metasurfaces make it practical

Metasurfaces are engineered interfaces that contain a thin layer of plasmonic or dielectric nanostructures capable of manipulating light in a desirable manner. Advances in metasurfaces have led to various practical applications ranging from lensing to holography. In this talk, we are going to share our recently developed flat optical devices with you. We have proposed and experimentally demonstrated several metasurface devices with unusual functionalities. The first example is the helicity multiplexed broadband metasurface hologram, which contains two sets of hologram patterns operating with opposite incident helicities. Two symmetrically distributed off-axis images are interchangeable by controlling the helicity of the input light. After that, we are going to talk the multifunction metasurface devices, whose functionalities are controlled by changing the helicity of the incident light. The final application of metasurface that we will discuss is the vortex beam generator. The cylindrically polarized vortex beams carrying orbital angular momentum are experimentally demonstrated based on a single metasurface with subwavelength pixels. The metasurface devices open new avenues for future application of miniaturized optical devices.

Dandan Wen and Fuyong Yue are two PhD students in IPaQS. Details about their research can be found here (http://nanophotonicslab.eps.hw.ac.uk/).