High sensitivity detection of NO_(2) employing cavity ringdown spectroscopy and an external cavity continuously tunable quantum cascade laser

摘要

A trace gas sensor for the detection of nitrogen dioxide based on cavity ringdown spectroscopy (CRDS) and a continuous wave external cavity tunable quantum cascade laser operating at room temperature has been designed, and its features and performance characteristics are reported. By measuring the ring-down times of the cavity at different concentrations of NO_(2), we report a sensitivity of 1.2 ppb for the detection of NO_(2) in Zero Air.