Berlin 2005 – scientific programme

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HL: Halbleiterphysik

HL 38: Halbleiterlaser II

HL 38.5: Talk

Monday, March 7, 2005, 11:00–11:15, TU P-N201

Loss studies in T-shaped waveguides for the midinfraredspectral region — •Thomas Herrle, Stefan Schmult, Markus Pindl, Ulrich Schwarz, and Werner Wegscheider — Institut für Experimentelleund Angewandte Physik Universität Regensburg, 93040 Regensburg

Intersubband emitters with active regions of lower dimensionality have attracted a lot of interest in recent years, since basic theoretical considerations predict a decrease of non-radiative losses in lower dimensional systems. To this end experiments on active regions using quantum-dot systems [1, 2] and quantum-wire systems [3] instead of conventional coupled quantum-well systems have been published recently. Here we present loss studies for a T-shaped waveguide for the quantum-wire intersubband emitter device reported in [3]. We present how such a T-shaped waveguide structure can be optimized regarding the confinement factor and the waveguide losses due to free carrier absorption. These waveguide losses turn out to be reduced in the quantum-wire cascade structure compared to the underlying conventional quantum-well structure. The presented waveguide calculations are the basis for the realization of a quantum-wire intersubband laser for the midinfrared spectral region.

[1] N. Ulbrich, J. Bauer, G. Scarpa, R. Boy, D. Schuh, G. Abstreiter, S. Schmult, and W. Wegscheider, Appl. Phys. Lett. 83, 1530 (2003)

[2] S. Anders, L. Rebohle, F. F. Schrey, W. Schrenk, K. Unterrainer, and G. Strasser, Appl. Phys. Lett. 82, 3862 (2003)

[3] S. Schmult, I. Keck, T. Herrle, W. Wegscheider, M. Bichler, D. Schuh, and G. Abstreiter, Appl. Phys. Lett. 83, (2003)