Published online by Cambridge University Press: 22 February 2011
High intensity pulsed beams of photons, electrons and ions provide extremely efficient means for electronically exciting solids near their surfaces. Among these three, laser beams with ever-increasing time resolution have also served as diagnostic probes to clarify the picosecond time scale on which interchange of energy between the electronic and the vibrational states of solids takes place at very high excitation energy densities. Because of this rapid transfer of electronic excitation to heat, pulsed beams provide versatile tools to investigate transient thermodynamic phenomena in solids, particularly those associated with metastable phases such as amorphous silicon.