Tamm Plasmon Resonance in Mesoporous Multilayers: Toward a Sensing Application

A novel optical sensor is proposed, based on the normal-incidence excitation of Tamm plasmons at the interface between a multilayer of porous SiO2 and TiO2, acting as a permeable Bragg reflector, and a flat gold film. Transmittance spectra reveal a sharp Tamm mode within the stop-band of the distributed Bragg reflector, the spectral position of which was monitored upon exposure to various solvents, demonstrating the sensitivity of the device to changes of refractive index.