@inproceedings{9ed02a75c310484c8995ef4e5c4c6463,
title = "Quantum-cascade lasers without injector regions",
abstract = "We present the status of quantum-cascade lasers without injector regions, based on a four- and five-level staircase, respectively. First lasers were realized at a wavelength of ∼10 μm. By applying an optimized design, we achieved high performance injectorless quantum-cascade lasers emitting at ∼6.7 μm. On the basis of this design, we investigated the influence of doping density and the number of periods of active sections. A sample with a doping sheet density of 2.5×1010 cm-2 and 60 periods of active sections shows record low threshold current densities of 0.75 kA/cm2 at 300 K. Recently, we have further extended the wavelength range even down to ∼4.2 μm.",
keywords = "Intersubband lasers, Mid-infrared lasers, Quantum-cascade lasers, Semiconductor lasers",
author = "A. Friedrich and Amann, {M. C.}",
year = "2007",
doi = "10.1117/12.697562",
language = "English",
isbn = "0819465984",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
booktitle = "Novel In-Plane Semiconductor Lasers VI",
note = "Novel In-Plane Semiconductor Lasers VI ; Conference date: 22-01-2007 Through 25-01-2007",
}