| Abstract: | Tunable mid‐infrared laser sources are the key to precision optical trace gas detection. Difference‐frequency generation (DFG) based laser sources are among a few practical laser sources that have demonstrated ultra‐high detection sensitivities during real‐world applications when combined with appropriate signal enhancing and noise reduction spectroscopic techniques. This article will discuss the technical approaches, illustrate application examples of DFG sources, and offer perspectives to competing technologies. |
