5. Airborne photoacoustic multi-gas detectors

5.1 Application to gases other than methane

Any gas absorbing in the IR is potentially detectable, and the detection limit obtained is directly linked to the absorption coefficient of the gas and the power of the laser emitting at the wavelength in question. Advances in medium-IR lasers open up a wide range of possibilities in terms of accessible gases. Table 2 shows the detection limits that have been or could be achieved for various gases, using near-IR laser diodes (DL: estimated power 10 mW) or quantum cascade lasers (QCL: estimated power 25 mW) in conjunction with the detector described above.