Tamm plasmon resonance sensor using porous films

B. AUGIE; M. C. FUERTES; P. C. ANGELOMÉ; A. FAINSTEIN; G. J. A. A. SOLER-ILLIA

Buenos Aires

Congreso; 14th International Meeting on Chemical Sensor IMCS15; 2014

A new type of optical sensor is proposed, based on the resonant excitation of Tamm surface plasmons. These electromagnetic modes, confined at the interface between a noble metal layer and a one-dimensional photonic crystal (Distributed Bragg Reflector, DBR), offer a promising platform combining high sensitivity and facile instrumentation. Non-intrusive optical interrogation is carried out by simple normal incidence reflectivity measurement for a fixed wavelength of illumination, or by acquisition of a full reflectance spectrum with white light illumination. Instrumental to the consideration of this structure for a sensing application is the constitution of the DBR from porous dielectric layers, allowing the analyte to access the region of high electric field induced by the optical excitation of Tamm plasmons near the metal surface. The sharp resonance condition associated with this interface mode could be used to probe minute changes of refractive index inside the porous nanostructure, thereby allowing real-time and sensitive monitoring of target molecules penetrating the porous network. In addition, the structure inherits further desirable properties from the porous layers, offering the possibility of selective functionalisation of each layer independently and within different regions of local electric field enhancement.