1999 Summer Research Faculty-Student Team

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Dr. James Heyman and Pelagia Neocleous

James Heyman is a Physics professor at Macalester College.
Pel Neocleous is a Physics/Mathematics major in her second year at Macalester

Construction of an Ultrafast Terahertz Spectrometer
James Heyman and Pelagia Neocleous
Department of Physics and Astronomy, Macalester College

Paul Crowell
Department of Physics, University of Minnesota

It is possible to generate ultra-short pulses of electromagnetic radiation with femtosecond lasers. These pulses can be used to perform pulsed spectroscopy at THz (1012Hz) frequencies with picosecond time resolution. This is an important development in condensed matter physics, because many of the fundamental excitations of solids occur at THz frequencies. Support from the MERSEC College Faculty-Undergraduate Research Team Fellowship has allowed us to construct an ultrafast THz spectrometer. We used the system to study THz emission from InAs in high magnetic field, and have shown that InAs is an efficient radiation source for further experiments. Further work is under way to understand and optimize the THz emission from InAs. The THz spectrometer will then be used to perform time-resolved spectroscopy on a variety of systems, including traditional semiconductor quantum wells and magnetic semiconductors. These types of systems will be the building blocks of the spin injection devices which are the goal of the Magnetic Heterostructures Initiative.