University
of Toronto
Physics Department
Quantum Optics and Condensed Matter
MONDAY SEMINAR
University
of Toronto
MONDAY SEMINAR
| Speaker : | PROF MARK STOCKMAN
Department of Physics and Astronomy Georgia State University Atlanta, GA |
| Topic : | Femtosecond and Attosecond Chaos, Giant Fluctuations
of Local Optical Fields
and Nonlinear Optical Enhancement in Disordered Clusters, Nanocomposites and Rough Surfaces |
| Time : | Monday, January 24, 2000 at 12:10 p.m. |
| Place : | Room 408, Burton Tower 60 St. George Street / 255 Huron Street |
Abstract
The talk will begin with an overview of enhanced nonlinear-optical processes in random systems (large clusters, composites and rough surfaces). The optical enhancement is due to chaotic, fluctuating local fields. The giant spatial fluctuations of the local fields reflect underlying chaos of the polar eigenmodes (surface plasmons) in such systems, which exhibits many properties of wave or quantum chaos.
The phenomena of the giant optical enhancements in disordered systems
have been studied both theoretically and experimentally for steady-state
excitation. In this talk we will emphasize a very recent development related
to ultrafast (femto- and attosecond) photoprocesses in disordered systems.
The “Ninth wave effect" [Phys. Rev. Lett. 2000 (tentatively scheduled
for January 24 issue)] has been predicted for femtosecond excitation where
dissipation does not have enough time to run its course, but giant fluctuations
of local fields do set on. These fluctuations cause concentration of the
whole energy accumulated by the large system in a narrow spatial region
leading to giant femtosecond spikes of the local fields. We will also discuss
attosecond phenomena. These developments open up exciting new possibilities
for a wide class of giant ultrafast nonlinear phenomena.
Local Host: John Sipe 
(416-978-4517)