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arXiv · 0904.2516

THz-pump -- THz-probe spectroscopy of semiconductors at high field strengths

Matthias C. Hoffmann·Janos Hebling·Harold Y. Hwang·Ka-Lo Yeh·Keith A. Nelson
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Abstract

Pumping n-type GaAs and InSb with ultrafast THz pulses having intensities higher than 150 MW/cm2 shows strong free carrier absorption saturation at temperatures of 300 K and 200 K respectively. If the energy imparted to the carriers exceeds the bandgap, impact ionization processes can occur. The dynamics of carrier cooling in GaAs and impact ionization in InSb were monitored using THz-pump/THz probe spectroscopy which provides both sub-bandgap excitation and probing, eliminating any direct optical electron-hole generation that complicates the evaluation of results in optical pump/THz probe experiments.

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Matthias C. Hoffmann, Janos Hebling, Harold Y. Hwang, Ka-Lo Yeh, Keith A. Nelson. 2009-04-16. THz-pump -- THz-probe spectroscopy of semiconductors at high field strengths. https://doi.org/10.1364/josab.26.000a29

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