Enhanced infrared absorption with dielectric nanoparticles

Enhanced infrared absorption is demonstrated for anthracene coating polar dielectric nanoparticles of silicon carbide and aluminum oxide. An enhancement factor greater than 100 was measured near the surface of silicon carbide particles. This is the result of the enhanced optical fields at the surface of the particles when illuminated at the surface phonon resonance frequencies. This phonon resonance effect is analogous to plasmon resonance that is the basis of surface enhanced infrared absorption and surface enhanced Raman scattering. The results have implications for near-field microscopy, the characterization of nano-optical devices, and chemical sensing. In addition, the methodology used for surface phonon analysis of particles is useful for simulating comet and interstellar dust spectra. (C) 2003 American Institute of Physics.