Contents 1. TDLAS Overview
Gas sensors based on Tunable Diode Laser Absorption Spectroscopy (TDLAS) enable sensing trace concentrations of many critical gases in a broad array of applications. TDLAS gas analyzers rely on well-known spectroscopic principles and sensitive detection techniques coupled with advanced diode lasers, and often with optical fibers. The principles are straightforward: Gas molecules absorb energy in narrow bands surrounding specific wavelengths in the electromagnetic spectrum At wavelengths slightly different than these “absorption lines”, there is essentially no absorption. By (1) transmitting a beam of light through a gas mixture sample containing a quantity of the target gas, (2) tuning the beam's wavelength to one of the the target gas's absorption lines, and (3) accurately measuring the absorption of that beam, one can deduce the concentration of target gas molecules integrated over the beam's path length.
