High sensitivity point monitoring of ozone, and high resolution spectroscopy of the ν_3 band of ozone using a tunable semiconductor diode laser

Abstract

Accurate measurements of the wavenumbers of more than 100 lines in the ν₃ band of ozone have been made using a tunable semiconductor diode laser and a temperature-stabilized germanium etalon. The accuracy for the line centers is estimated to be within 3–10 MHz and compares well with the accuracy attained using more complicated heterodyne techniques. The relevance of these results to ozone monitoring instruments based on CO₂ lasers is discussed. The tunability of the diode laser is also exploited to monitor ambient concentrations of ozone in the presence of interfering molecular species. A detection sensitivity of ~0.5 ppb of ozone is demonstrated.