Photoacoustic detection of nitric oxide with a Helmholtz resonant quantum cascade laser sensor

Nitric oxide detection has been performed with a Helmholtz resonant photoacoustic sensor previously developed in Reims. The cell was coupled with a continuous wave distributed feedback quantum cascade laser working at cryogenic temperature in continuous wave mode in the 5.4 μm region. A detection limit of 20 ppb of nitric oxide in nitrogen with a laser power of 3 mW can be predicted. Possible applications and improvements are discussed.