J. Phys. IV France 125 (2005) 3-5
Atmospheric detection of N2O and CO2 with a pulsed optical parametric oscillatorA. Miklós1, M. Gomes da Silva2 and P. Hess1
1 Institute of Physical Chemistry, University of Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
2 Laboratório de Ciências Físicas - CCT , Universidade Estadual do Norte Fluminense, Av. Alberto Lamego, 2000 - Pq. Califórnia, Campos dos Goytacazes, CEP: 28013-602, RJ, Brasil
Nitrous oxide (N2O) concentrations in ambient air were measured by photoacoustic spectroscopy. The light source, a grazing-incidence optical parametric oscillator (GIOPO) with a periodically-poled lithium niobate (PPLN) crystal, was pumped by a pulsed Nd:YAG laser. Measurements were performed in the spectral region of 2.76-2.91 m containing N2O, CO2, and water absorption lines. Two serial water filters filled with CaCl2 and P2O5 were used to reduce the concentration of water to the level of several parts per billion by volume (ppbv). Using a standard mixture of 50.6 parts per million by volume (ppmv) of N2O in synthetic air to calibrate the photoacoustic signal, a value of 310 30 ppbv was found for the concentration of N2O in the ambient atmosphere.
© EDP Sciences 2005