A. Huber, N. Ocelic, D. Kazantsev, and R. Hillenbrand
Applied Physical Letters 87, p.81103 (2005)
We demonstrate that mid-infrared surface phonon polariton propagation on a SiC crystal can be imaged by scattering-type near-field optical microscopy. From the infrared images, we measure the wave vector and the propagation length of locally excited surface phonon polaritons. Our method can be also applied to surface plasmon polaritons and allows to study surface polaritons in subwavelength-scale structures.