Laser-based Gas Sensing

Laser-spectroscopic methods are attracting great interest in various areas, notably in the field of gas monitoring and analysis. Apart from high sensitivity and specificity they offer additional important features such as the lack of time-consuming sample preparation, on-line and remote sensing. The performance depends crucially on the availability of appropriate laser sources and detection schemes. Here we discuss various point-monitoring laser-based systems employing different lasers (near-infrared diode lasers, gas lasers, quantum cascade lasers and nonlinear optical devices) and different detection techniques (long-path absorption, photoacoustic and cavity ring-down). The performance of selected laser spectrometers is illustrated with examples including laboratory gas analyses and in situ measurements of traffic emissions.