Regensburg 2007 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 19: Spin controlled transport I
HL 19.8: Vortrag
Dienstag, 27. März 2007, 12:30–12:45, H14
Picosecond Polarization Detector for Infrared and Terahertz Radiation — •J. Kiermaier1, W. Weber1, S.N. Danilov1, D. Schuh1, Ch. Gerl1, W. Wegscheider1, D. Bougeard2, Gerhard Abstreiter2, W. Prettl1, and S.D. Ganichev1 — 1Faculty of Physics, University of Regensburg, 93040 Regensburg, Germany — 2Walter-Schottky Institute, TU Munich, 85748 Garching, Germany
We report on a room temperature detector allowing to measure and characterize the state of polarization of infrared and terahertz laser radiation with picosecond time resolution. The ellipticity of radiation is analyzed applying simultaneously the circular and the linear photogalvanic effect (CPGE, LPGE) as well as the photon drag effect [1], which are monitored by different units in one single detector. Access to radiation helicity is provided by CPGE in quantum wells (QWs) resulting in a signal proportional to the radiation helicity. To reconstruct the whole state of radiation polarization we use additionally LPGE which is sensitive to linear polarization and the photon-drag effect which is polarization insensitive providing a reference of radiation power. For detector elements based on CPGE and LPGE we applied (113)-grown SiGe or GaAs QWs. The photon drag detector was prepared from germanium crystals irradiated along the [100]-crystallographic axis. The detector units are connected to an analytical part, which converts the measured signals into explicit information about the polarization state of the incoming laser beam.
[1] S.D. Ganichev, and W. Prettl, Intense Terahertz Excitation of Semiconductors, Oxford University Press, (2006).