TDLAS works by tuning a diode laser to a specific wavelength that corresponds to an absorption line of the target gas. As the laser passes through the gas sample, molecules absorb light at that wavelength. The amount of absorption reveals the gas concentration—often down to. us industries, providing high sensitivity, selectivity, and real-time analysis. It is widely used in industries such as natural gas, petrochemicals, refining, and environmental monitoring, where accurate, real-time gas. Tunable Diode Laser Absorption Spectroscopy (TDLAS) is a powerful and precise technique used for gas detection, based on the absorption of laser light by specific molecular species.