[printer friendly version]

Special Seminar / Ph. D. Defense

"Department of Physics and Astronomy, TAMU"

Matt Springer
Department of Physics and Astronomy, TAMU


The propagation of ultrashort femotsecond laser pulses in linear dielectric materials is determined in the time, space, and frequency domains by linear Maxwell optics through dispersion and diffraction. For intense pulses, pulse propagation is additionally modified by nonlinearities in the medium such as the optical Kerr effect, plasma generation, and self-phase modulation.

In this work we report the results of several experiments on the propagation of ultrashort pulses. In the linear regime, we characterize the temporal evolution of an ultrashort pulse during propagation through a linear dielectric under anomalous dispersion. The pulse evolution departs from the group velocity and group delay dispersion approximations, leading to the formation and propagation of optical precursors.

We also report the results of experiments involving time-resolved imaging of the propagation of ultrashort pulses in dielectric materials. The nonlinearities induced by the propagation of the intense ultrashort pulse produce changes in the complex refractive index of the nonlinear material, and these changes may be probed by a weak femtosecond probe pulse which may be used to image the nonlinearity in a time-resolved manner. We use this method to characterize femtosecond pulses in air and liquid, especially in the regime of optical filamentation.

Friday, October 4, 2013
IQSE 578, 12:00 p.m.
Mitchell Physics Building

Institute for Quantum Science and Engineering
Texas A&M University