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Quantum cascade lasers for the mid-infrared region

Quantum cascade lasers are new intersubband light sources in which the wavelength can be tailored over a broad range of the infrared spectrum using the same heterostructure material by changing the active layer thickness. Room temperature operation at 5 and 8.5 μm has been achieved. These are the first semiconductor lasers to operate at 300 K and above in this wavelength region.