Plasmonic heterostructures for sensing applications

Abstract

We present a study of the optical response of an array of plasmonic nanoelements on top of a two-dimensional photonic crystal. The excitated collective plasmons together with the role of the photonic crystal that intensifies their excitation give rise to a particularly interesting electric field distribution. These properties, which have been optimized by tuning the heterostrucutre parameters, are specially suitable to design a sensor of refractive index changes. Using numerical simulations, we study the behavior of our basis heterostructure and its response when the test material is put in contact with the system. The study evidences the high effciency of the heterostructure, whose properties result in a sensitivity of the sensor so much higher than that obtained in other similar sensors