Quantum Cascade Lasers: Review, Applications and Prospective Development
A review on quantum cascade lasers (QCLs) is presented. An introductory overview is prefaced, including a brief description of their beginnings and operating basics. Material systems used, as well as growth methods are depicted. The possibility of developing GaN-based QCLs is also shown. The applications of these structures cover a broad range, including spectroscopy, astronomy, medicine and free-space communication, as well as applications to near-space radar and chemical/biological detection. Therefore, a number of state of the art applications are described in different fields. Finally, a brief assessment of the overall state of research of QCLs and volume-production is included.
Keywords: Quantum cascade laser (QCL); photoacoustic spectroscopy, sensors, trace-gas detection, plasma species, cavity ring down spectroscopy