Negative free carrier absorption in terahertz quantum cascade lasers
Mesoscale and Nanoscale Physics
2016-12-07 v1
Abstract
We analyze the peculiar case where the free carrier absorption arising from LO phonon absorption-assisted transitions becomes negative and therefore turns into a gain source for quantum cascade lasers. Such an additional source of gain exists when the ratio between the electronic and the lattice temperatures is larger than one, a condition that is usually fulfilled in quantum cascade lasers. We find a gain of few cm's at 200K. We report the development of a terahertz quantum cascade laser operating in the negative free carrier absorption regime.
Cite
@article{arxiv.1611.09269,
title = {Negative free carrier absorption in terahertz quantum cascade lasers},
author = {C. Ndebeka-Bandou and M. Rösch and K. Ohtani and M. Beck and J. Faist},
journal= {arXiv preprint arXiv:1611.09269},
year = {2016}
}