In the air we breathe, dozens of chemical compounds are floating around — from completely harmless ones to those that can negatively affect human health and the environment. Detecting them quickly and with high accuracy requires tools capable of “looking into” the unique optical signatures of these substances. This is precisely the focus of the SWIRLS project (Sensitive Wideband Infrared Laser Spectroscopy), which aims to create a new class of instruments for exceptionally sensitive, wideband laser spectroscopy.

Most volatile chemical compounds — including many toxic gases and pollutants — have characteristic absorption lines in the mid‑infrared (MIR) range. These can be thought of as a set of “barcodes,” each molecule revealing its identity through its spectral fingerprint. With a precision laser operating in the right part of the spectrum, it becomes possible to detect even extremely small amounts of a given substance.