Long wavelength superlattice quantum cascade lasers at lambda similar or equal to 17 mu m

We report the realization of the first semiconductor injection lasers based on intraband transitions with emission wavelengths extending beyond the atmospheric windows. The structure uses the quantum cascade scheme with "chirped" superlattices as active material. Laser action in pulsed operation is achieved at lambda ~ 17 microns up to 150 K, with peak output powers of ~ 12 mW at cryogenic temperatures.