Thermal emission of two-color polarized infrared waves from integrated plasmon cavities

We have demonstrated that orthogonally polarized two-color infrared waves thermally emitted from gratings integrated onto a single Au chip open a way for simple and efficient chemical analysis. Each component grating is made of high-aspect cavities with a width on the order of 100 nm and a depth close to 1 mu m, and generates linearly polarized and narrow-band midinfrared light by the organ pipe resonance of surface plasmons. Effectiveness of the integrated grating emitters for nondispersive infrared analysis has been shown on the basis of a model experiment for determining the concentration of a specific chemical compound in liquids. (C) 2008 American Institute of Physics.