Abstract

Chemical sensing using mid-infrared laser absorption spectroscopy (MIR-LAS) in the molecular fingerprint region from 3 to 20 µm has been established as a powerful diagnostic tool. To improve the efficiency of many industrial processes but also to control their impact on the environment, more insight into the (plasma) chemistry is required. Therefore, the detection and quantitative measurement of important species is a major challenge in industrial applications. We will discuss examples of species detection applying laser-based diagnostics in the mid-infrared using quantum cascade lasers (QCLs) and interband cascade lasers (ICLs). A further increase in sensitivity to detection limits of ppm down to ppt levels can be achieved by combining QCLs with cavity-enhanced techniques based on optical cavities.

© 2015 Optical Society of America