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 high-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 plasmas by the field of a laser-excited surface wave. Two different excitation regimes can exist depending on the wavelength and the angle of incidence of the laser. This effect may have interesting experimental consequences in hot electron generation and x-ray emission due to breaking of the resonant plasma wave.