Surface phonon polaritons on SiC substrate for surface-enhanced infrared absorption spectroscopy

We numerically investigate the optical field enhancement in metallic microstructures on the surface of polar dielectrics due to the excitation of surface phonon polaritons (SPhPs). The optical field enhancement at the edge of the microstructures is attributed to the contribution of two components: the resonant coupling of the conventional optical antenna and the excitation of SPhPs. By simulation, we found the amplitude of the local field enhancement is up to 10(6) times. The dependence of field enhancement on incident polarizations and angles is also investigated. The achieved strong field enhancement combined with easy fabrication can potentially lead to promising applications in optical bio-sensing such as surface-enhanced infrared absorption spectroscopy. (C) 2010 Optical Society of America