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HL: Halbleiterphysik

HL 16: Semiconductor laser I

HL 16.2: Vortrag

Dienstag, 28. März 2006, 11:15–11:30, BEY 154

Gain and threshold current in quantum-wire intersubband laser structures — •Thomas Herrle, Stephan Haneder, and Werner Wegscheider — Institut für Experimentelle und Angewandte Physik Universität Regensburg, 93040 Regensburg

In recent years quantum cascade structures with quantum-wire and quantum-dot active regions are more and more investigated. The reason for this is the theoretical prediction of a decrease of non-radiative losses in lower dimensional systems. This is experimentally confirmed by the superior performance of quantum cascade lasers in an applied magnetic field, where the lower dimensionality of the electron system is achieved by the Landau quantization [1]. In the presented work we calculate the gain and the threshold current for a quantum-wire intersubband laser structure proposed in [2], which is fabricated by the cleaved edge overgrowth technique. We report on the influence of the formation of excited states in these structures on the gain and threshold current. It turns out that these excited states have to be avoided in the sample design of such structures to end up with higher gain values in the quantum-wire structures compared to conventional quantum-well systems.
C. Becker, C. Sirtori, O. Drachenko, V. Rylkov, D. Smirnov, J. Leotin, Appl. Phys. Lett. 81, 2941 (2002).
Ingo Keck, Stefan Schmult, Werner Wegscheider, Martin Rother, Andreas P. Mayer, Phys. Rev. B 67, 125312 (2003).