High sensitivity point monitoring of ozone, and high resolution spectroscopy of the nu(3) band of ozone using a tunable semiconductor diode laser.

Accurate measurements of the wavenumbers of more than 100 lines in the nu(3) 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 CO(2) 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.