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Exciton-Population Inversion and Terahertz Gain in Resonantly Excited Semiconductors

M. Kira·S. W. Koch
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Abstract

The build-up of exciton populations in resonantly laser excited semiconductors is studied microscopically. For excitation at the $2s$-exciton resonance, it is shown that polarization with a strict $s$-type radial symmetry can be efficiently converted into an incoherent $p$-type population. As a consequence, inversion between the $2p$ and $1s$ exciton states can be obtained leading to the appearance of significant terahertz gain.

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M. Kira, S. W. Koch. 2004-03-26. Exciton-Population Inversion and Terahertz Gain in Resonantly Excited Semiconductors. https://doi.org/10.1103/physrevlett.93.076402

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