Plasma effects in attosecond pulse generation

Particle-in-cell simulations have been used to explore further the role of plasma effects on the high harmonic spectrum generated in intense ultrarelativistic (UR) laser-plasma interactions. From a study of the electron dynamics during the laser-plasma interaction a strong correlation was established between the reflected laser pulses and plasma effects. The sources of intense attosecond pulses were found to originate within the plasma at sites of high electron density concentrations at which there is a correspondingly strong generation of electrostatic fields.