Chirality- and Wavelength-Multiplexed Focusing of Surface Plasmons

Surface plasmons (SPs) is a vital form of electromagnetic wave confined to the metal-dielectric interface. Since the capability of guiding light within subwavelength scale, a great deal of plasmonic devices emerged successively. Over the past few years, in-plane SPs controlled by artificially structured surfaces are of great promise for information transmission in ultracompact integrated optical circuit, especially in terahertz (THz) near-field photonics. Owing to the exploitation of holographic principles in two-dimensional surface, we theoretically and experimentally demonstrate a generic design strategy to steer the SP waves to several focus spots depending on the wavelength and chirality.