Electric Field Tuning of Plasmonic Absorption of Metallic Grating with Twisted Nematic Liquid Crystal

Abstract

Tunable surface plasmon absorption was achieved by applying an electric field to a metallic grating with a twisted nematic-liquid crystal (TN-LC) layer. The metallic grating caused the surface plasmon resonance (SPR) and aligned the TN-LC layer. A TN-LC layer was achieved with the metallic grating and rubbed counter substrate. Transverse electric (TE)-mode incident light was irradiated from the counter substrate and converted to transverse magnetic (TM) mode at the metallic grating surface. An electric field was used to control polarization direction rotation. The SPR with the TE-mode incident light was simulated using a finite-difference time-domain method; the experimental and theoretical results agreed well.