Mobile photoacoustic trace-gas monitoring using high power quantum cascade lasers as pump sources operated near room temperature

Summary form only given. Photoacoustic detection offers the advantage of wavelength-independent and simple operation and low cost. However, since the measurable photoacoustic signal is proportional to the laser power absorbed by the gas inside the detection cell, high power lasers are normally used as pump sources with typical output powers in the watt regime, e.g. line-tunable CO/sub 2/ lasers. The highly sensitive multipass resonant photoacoustic cell employed in our set-up is in the first place optimized to be operated with continuous-wave CO/sub 2/ lasers as pump sources but also well suited for other laser sources such as quantum-cascade lasers (QCLs), as is demonstrated here.