Resonant coupling between surface and interface plasma waves in high-density sharp-edged plasmas produced by ultrafast laser pulses

We consider the interaction between an ultrashort laser pulse and a hot hig h-density sharp-edged laser-created plasma resulting from a microstructured target with a double-step density profile. We demonstrate that an electron plasma wave can be resonantly driven at the density jump between the two p lasmas by the field of a laser-excited surface wave. Two different excitati on regimes can exist depending on the wavelength and the angle of incidence of the laser. This effect may have interesting experimental consequences i n hot electron generation and x-ray emission due to breaking of the resonan t plasma wave.