@article {Callan:106,
	title = {Ultrafast Electron and Lattice Dynamics in Semiconductors at High Excited Carrier Densities},
	journal = {Chemical Physics},
	volume = {251},
	year = {2000},
	pages = {167{\textendash}179},
	abstract = {We directly measure ultrafast changes in the dielectric function of GaAs over the spectral range from the near-IR to the near-UV caused by intense 70-fs laser excitation. The dielectric function reveals the nature of the ultrafast phase transformations generated in the material, including a semiconductor-to-metal transition for the strongest excitations. Although the electron and lattice dynamics are complex when large carrier densities are excited between 1 and 20\% of the valence electrons the dominant processes and their timescales can be deduced.},
	author = {J. Paul Callan and A. M.-T. Kim and Huang, L. and Mazur, E.}
}
