This paper presents a triple-wavelength infrared plasmonic thermal emitter using a periodic arrangement of hybrid dielectric materials within a tri-layer metal/dielectric/metal structure. The proposed arrangement makes it possible to sustain multiple resonance of localized surface plasmons (LSP), thereby providing an additional degree of freedom by which to vary the resonant wavelengths in the medium infrared region. Variations in the effective refractive index due to the different modal distribution within dielectric gratings results in multiple LSP resonances, and the resonant wavelengths can be easily tuned by altering the compositions of hybrid dielectric materials. The measured dispersion relation diagram and the finite difference time domain simulation indicated that the resonances were localized. They also indicate that the magnetic fields generated by the multiple LSP modes exhibit distribution patterns similar to that of a standing wave in the periodic arrangement of the hybrid dielectric layer, each of which presents an emission peak corresponding to a different modal order.
ASJC Scopus subject areas