Plasmonic characteristics of metallic nano-ring structures

摘要

We proposed and demonstrated the metallic nano-ring structure using polystyrene lift-off process to enhance the sensitivity of an SPR surface. The double layered SPR structures are optimized using the finite-difference time-domain method for the width, thickness, and period of the polystyrene beads. The optimum thickness of the metal film and the metallic nano-ring is 30 and 20 nm in the 214 nm wide nano-hole size, respectively. The metallic nano-ring structures are fabricated with monolayer polystyrene beads of 400 nm wide. The various metallic nano-ring structures have been obtained by transferring method. The sensitivities of the conventional SPR sensor and the metallic nano-ring structures are obtained to 42.2 and 52.1 degree/RIU, respectively.