Microfluid-enabled fine tuning of circular dichroism from chiral metasurfaces

We propose and numerically demonstrate a microfluid-enabled spin-selective chiral metasurface with tunable circular dichroism. The chiral metasurface consists of periodic array of gammadion-like multilayer nanostructures. With the help of microfluidic technology, fine tuning of circular dichroism from the chiral metasurface can be achieved. Numerical results show that a broad tuning range of 40 nm can be achieved, while the circular dichroism only shows a slight decrease. Such a proposed device could be potentially useful for chirality detection, polarimetric imaging, and spin-communications.