Evidence for a dense electron-hole plasma close to the melting phase transition in silicon

We have studied both theoretically and experimentally the dynamics of laser-induced electron-hole plasmas created at the surface of silicon using the strong synergy observed during simultaneous illumination by two picosecond pulses of different wavelengths. In a range of intensities up to those capable of producing a phase transition, we find good agreement between the results of our experiments and the predictions of a conventional model for pulsed laser heating.