Phonon-polariton waves on the surface of SiC crystal

The excitation and propagation of traveling phonon-polariton waves on the surface of silicon carbide (SiC) excited by light at a frequency close to the lattice resonance have been investigated. These waves are excited in the presence of the boundary of a metal mask deposited on the crystal surface. The use of the Green’s function has been shown to provide good qualitative agreement with the observed distribution of the amplitude and phase of the field on the surface under these experimental conditions. It has been shown that only consideration of the mask boundary as an extended source of traveling surface waves, which removes the inhibition of the generation of waves in the noncoincidence of the wave vector, cannot quantitatively describe the phenomenon. The spatial resolution of the used scanning near-field optical microscope is no worse than 150 nm at a wavelength of 10 μm.