@article { ISI:000167275600012,
	title = {New frontiers in quantum cascade lasers and applications},
	journal = {IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS},
	volume = {6},
	number = {6},
	year = {2000},
	month = {NOV-DEC},
	pages = {931-947},
	publisher = {IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC},
	type = {Article},
	address = {345 E 47TH ST, NEW YORK, NY 10017-2394 USA},
	abstract = {Recent advances and new directions in quantum cascade (QC) lasers are discussed in this paper. Invented in 1994 following many years of research on band-structure engineered semiconductors and devices grown by molecular beam epitaxy, this fundamentally new laser has rapidly advanced to a leading position among midinfrared semiconductor lasers in terms of wavelength agility as well as power and temperature performance. Because of the cascaded structure, QC lasers have a slope efficiency proportional to the number of stages. Devices with 100 stages having a record peak power of 0.6 W at room temperature are reported here. QC lasers in the AlInAs-GaInAs lattice matched to InP material system can now be designed to emit in the whole midinfrared range from 4 to 20 mum by appropriately choosing the thickness of the quantum wells in the active region. Using strained AlInAs-GaInAs, wavelengths as short as 3.4 mum have been produced, New results on QC lasers emitting at 19 mum, the longest ever realized in a III-V semiconductor laser, are reported. These devices use innovative plasmon waveguides to greatly enhance the mode confinement factor, thereby reducing the thickness of the epitaxial material. By use of a distributed feedback (DFB) geometry, QC lasers show single-mode emission with a 30-dB side-mode suppression ratio. Broad continuous single-mode tuning by either temperature or current has been demonstrated in these DFB QC lasers at wavelengths in two atmospheric windows (3-5 and 8-13 mum), with continuous-wave linewidths ,
	keywords = {chemical sensing, high-speed optoelectronic devices, injection lasers, intersubband transitions, mid-infrared, semiconductor heterostructures, unipolar semiconductor lasers},
	issn = {1077-260X},
	doi = {10.1109/2944.902142},
	author = {F. Capasso and C. Gmachl and Paiella, R and Tredicucci, A and Hutchinson, AL and Sivco, DL and Baillargeon, JN and Cho, AY and Liu, HC}
}
