Abstract

Using far-infrared radiation from the free-electron laser at the University of California, Santa Barbara, high-power photoconductivity experiments were performed on n-type GaAs:Si. In order to distinguish among the various mechanisms of the observed photoconductivity, we simultaneously monitored the Hall voltage and the photocurrent created by the photoexcited electrons. In this way the number and mobility of the electrons contributing to the photoconductivity were determined. At 4.2 K and in weak magnetic fields, 200- and 295-μm radiation in high-power pulses of 2-μsec duration was used to excite donor electrons from the bound 1s ground state. The experiments show that the photoconductivity arises from electrons that are excited into the conduction band, where they are further heated by the radiation.

© 1989 Optical Society of America

Generation of subnanosecond high-power far-infrared pulses by using a passive resonator pumped by a free-electron laser

J. Burghoorn, J. P. Kaminski, R. C. Strijbos, T. O. Klaassen, and W. Th. Wenckebach
J. Opt. Soc. Am. B 9(10) 1888-1891 (1992)

Proposal for the direct electromagnetic generation of coherent terahertz acoustic phonons in semiconductor superlattices at the University of California, Santa Barbara far-infrared free-electron-laser facility

T. E. Wilson
J. Opt. Soc. Am. B 6(5) 1058-1060 (1989)

Applications of far-infrared free-electron lasers to condensed-matter physics

W. M. Dennis
J. Opt. Soc. Am. B 6(5) 1045-1049 (1989)

Enhancement of ligand binding to myoglobin by far-infrared excitation from a free-electron laser

Bernard Gerstman, Mark Roberson, and Robert Austin
J. Opt. Soc. Am. B 6(5) 1050-1057 (1989)

Material applications of the far-infrared free-electron laser

John D. Simon, John E. Crowell, John H. Weare, and David R. Miller
J. Opt. Soc. Am. B 6(5) 1035-1044 (1989)