Seminars Archive
Norman Tolk
Abstract
Tuesday, June 20, 2000, 14:30
Seminar Room, ground floor, Building "T"
Sincrotrone Trieste, Basovizza
I.D. required for external visitors
Materials Physics Applications of Ultra-Fast Tunable High-Power Lasers
.
Norman Tolk
(Department of Physics and Astronomy, Vanderbilt University,
Nashville)
ABSTRACT
Ultra-Fast, High-Power Lasers such as the Optical Parametric Amplifier
(OPA) and the Free-Electron Laser (FEL), with a combined tunability of
20m to 200nm, high intensity (15 MW), short pulse structure (1 ps)
and high level of reliability, make these photon sources ideal for studying
a wide range of materials physics topics. Recent advancements will be discussed
including (a) first measurements of the vibrational lifetime of bond-center
hydrogen in crystalline silicon, (b) first FEL measurements of photoluminescence
excitation spectroscopy (PLE) from hydrogenated amorphous silicon (a-Si:H)
near the two-photon threshold, (c) Second Harmonic Generation (SHG) studies
of carrier injection into oxides, and (d) non-thermal wavelength-selective
materials alteration. Both FEL and FEL related work will be treated as
it relates to the linear and nonlinear interaction of light with matter.
Emphasis will be given to the role of hydrogen and deuterium at semiconductor
surfaces and interfaces.
This work is supported by the Office of Naval Research and the Department
of Energy.
