A multi-valley model for hot free-electron nonlinearities at 10.6 μm in highly doped n-GaAs G. Shkerdin, J. Stiens and R. Vounckx Eur. Phys. J. AP, 12 3 (2000) 169-180 Published online: 15 December 2000 DOI: 10.1051/epjap:2000185