Abstract
We used a new broadband spectroscopic technique to measure the dielectric function of GaAs over the spectral range of 1.5–3.5 eV following intense 70-fs laser excitation. The results provide the most detailed information thus far on the electron and lattice dynamics both above and below the fluence threshold for permanent damage, . There are three distinct regimes of behavior: lattice heating , lattice disordering (0.6–0.8) , and a semiconductor-to-metal transition . Below , the changes are completely reversible.
- Received 21 May 1997
DOI:https://doi.org/10.1103/PhysRevLett.80.185
©1998 American Physical Society