Long-wavelength (9-11 /spl mu/m) quantum cascade lasers

Summary form only given. Quantum Cascade (QC) lasers represent a fundamentally different semiconductor light-source based on the unipolar injection of carriers and on intersubband transitions between confined quantum states electrically pumped by resonant tunneling. In this paper QC lasers operating in the 9-11 μm infrared region are reported for the first time. Semiconductor lasers in the 8-13 μm atmospheric window are important for a wide range of applications from environmental sensing to industrial process control. In addition this work, combined with previous reports at shorter wavelengths, demonstrates that QC lasers are ideally suited to cover a wide spectral range by appropriate tailoring of the layer thickness using the same technologically advanced heterostructure material rather than low-band-gap semiconductors.