Electronically Controlled Surface Plasmon Dispersion and Optical Transmission through Metallic Hole Arrays Using Liquid Crystal

TLDR

Metal films perforated with sub‑wavelength hole arrays exhibit enhanced optical properties, and by tailoring their geometry they function as plasmonic crystals with flexible transmission for photonics, opto‑electronics, and sensing; converting these passive elements into actively controllable devices presents a new challenge. The study reports an electrically controlled nanostructured optical system that couples surface plasmon polaritonic crystals with a liquid crystal layer. The authors analyze how liquid crystal modulation alters surface plasmon dispersion, optical transmission, and the underlying mechanism. The effect enables active spectral tunability and switching across many applications.

Abstract

The enhanced optical properties of metal films periodically perforated with an array of sub-wavelength size holes have recently been widely studied in the field of surface plasmon optics. The ability to design the optical transmission of such nanostructures, which act as plasmonic crystals, by varying their geometrical parameters gives them great flexibility for numerous applications in photonics, opto-electronics, and sensing. Transforming these passive optical elements into devices that may be actively controlled has presented a new challenge. Here, we report on the realization of an electrically controlled nanostructured optical system based on the unique properties of surface plasmon polaritonic crystals in contact with a liquid crystal (LC) layer. We discuss the effect of LC layer modulation on the surface plasmon dispersion, the related optical transmission and the underlying mechanism. The reported effect may be used to achieve active spectral tuneability and switching in a wide range of applications.