Heidelberg 2015 – wissenschaftliches Programm
A 24.3: Vortrag
Mittwoch, 25. März 2015, 15:00–15:15, C/kHS
Sub-cycle resolved probe retardation in strong-field pumped dielectrics — •Adrian N Pfeiffer — Institute of Optics and Quantum Electronics, Abbe Center of Photonics, Friedrich Schiller University, Max Wien Platz 1, 07743 Jena, Germany
The ultrafast response of bulk solids to laser pulses in the strong-field regime is currently paving the way for novel applications of attosecond physics. According to theoretical studies, a possible underlying mechanism is that conduction band levels are transiently populated at the crests of the laser pulse, thereby switching the dielectric from an insulator into a conductor and back into an insulator within one optical cycle. Here, an experimental method is presented which delivers time-resolved information about strong-field processes that occur in dielectric solids during one laser cycle. The method is based on the well-known retardation of a probe pulse by a strong pump pulse. A close-to-collinear alignment of pump and probe beams facilitates the detection of sub-cycle dynamics with respect to an absolute time reference given by the interference signal of the pump and probe pulses. Comparing the sub-cycle resolved measurement of the probe delay to a calculation based on a two-band model reveals that the transient conduction band population affects the measurement in a characteristic way. Moreover, the measurement is sensitive to the interband dephasing time and hence delivers information about the coherence behavior of the strong-field induced conductivity.