@article { ISI:000273860400037,
	title = {Activation energy study of electron transport in high performance short wavelengths quantum cascade lasers},
	journal = {OPTICS EXPRESS},
	volume = {18},
	number = {2},
	year = {2010},
	month = {JAN 18},
	pages = {746-753},
	publisher = {OPTICAL SOC AMER},
	type = {Article},
	address = {2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA},
	abstract = {We present a method to study current paths through quantum cascade lasers (QCLs). The temperature dependence of the current is measured at a fixed voltage. At low temperatures we find activation energies that correspond to the energy difference between the injector ground state and the upper laser level. At higher temperatures additional paths with larger activation energies are found. Application of this method to high performance QCLs based on strained InGaAs/InAlAs quantum wells and barriers with different band-offsets allows us to identify individual parasitic current paths through the devices. The results give insight into the transport properties of quantum cascade lasers thus providing a useful tool for device optimization. (C)2010 Optical Society of America},
	issn = {1094-4087},
	doi = {10.1364/OE.18.000746},
	author = {Pfluegl, Christian and Diehl, Laurent and Lyakh, Arkadiy and Wang, Qijie and Maulini, Richard and Tsekoun, Alexei and Patel, C. Kumar N. and Wang, Xiaojun and Federico Capasso}
}
