Mouskeftaras, AlexandrosRode, Andrei V.Clady, RaphaëlSentis, MarcUtéza, OlivierGrojo, David2015-04-092015-04-090003-6951http://hdl.handle.net/1885/13207Two-photon ionization by focused femtosecond laser pulses initiates the development of micrometer-scale plasmas in the bulk of silicon. Using pump-and-probe transmission microscopy with infrared light, we investigate the space-time characteristics of these plasmas for laser intensities up to 10¹²W/cm². The measurements reveal a self-limitation of the excitation at a maximum free-carrier density of ffi1019 cm3, which is more than one order of magnitude below the threshold for permanent modification. The plasmas remain unchanged in the 100 ps timescale revealing slow carrier kinetics. The results underline the limits in local control of silicon dielectric permittivity, which are inherent to the use of single near-infrared ultrashort Gaussian pulses.This research has received financial support from the French National Research Agency (ANR 2010-JCJC-913- 01), the French Carnot Star Institute (Via-LASER), and the CNRS PICS Program No. 45052. A.R. is grateful for partial support by the Australian Research Council’s (Discovery Project DP 120102980) and by the Air Force Office of Scientific Research (USA, Grant No. FA 9550-12-1-0482).5 pageshttp://www.sherpa.ac.uk/romeo/issn/0003-6951/..."Publishers version/PDF may be used on author's personal website or institutional website" from SHERPA/RoMEO site (as at 09/04/15)2014-11-1010.1063/1.49015282015-12-10