Observation of Dyakonov surface waves.

We report the first experimental observation of Dyakonov surface waves existing at the interface of transparent anisotropic crystals. A Otto-Kretchmann configuration was used to excite the surface waves at the interface between a potassium titanyl phosphate biaxial crystal and an index-matching liquid fulfilling the conditions at which the waves exist. The signature of surface wave excitation was obtained by using enhanced polarization-conversion reflectance phenomena. We measured the cutoff propagation angles for different index-matching liquids, confirming the high sensitivity of the propagation conditions with the properties of the supporting interface.