Negative free carrier absorption in terahertz quantum cascade lasers

Autor: Ndebeka-Bandou, C., Rösch, M., Ohtani, K., Beck, M., Faist, J.
Rok vydání: 2016
Předmět:
Zdroj: Appl. Phys. Lett. 108, 091102 (2016)
Druh dokumentu: Working Paper
DOI: 10.1063/1.4942889
Popis: 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$^{-1}$'s at 200K. We report the development of a terahertz quantum cascade laser operating in the negative free carrier absorption regime.
Databáze: arXiv