Artificial optical activity in chiral resonant nanogratings

摘要

Nanogratings with chiral geometry are found to produce artificial optical activity (i.e., the ability of rotating the light polarization), though the composing materials are not optical active. This paper presents a thorough review of our recent study, from theory to experiment, on the optical activity in two types of chiral nanogratings: the dielectric gratings exhibiting the largest polarization rotation (up to 26.5°) observed to date, and the metallic ones producing simultaneous enhance transmission and enhanced optical activity. The polarization properties of the chiral gratings are demonstrated and the enhancement mechanism of optical activity due to various resonance processes are also revealed and interpreted.