Simultaneous NO and NO_2 DIAL measurement using BBO crystals

We report a new differential absorption lidar technique for measuring simultaneously the concentrations of NO and NO(2) in the atmosphere. The technique is based on the correlation of the 450-nm absorption band of NO(2) and 227-nm absorption band of NO by frequency doubling. This performance has been allowed by the advent of a new and highly efficient frequency doubling crystal: the beta-BaB(2)O(4). A test experiment on a NO/NO(2) emitter has been performed, demonstrating the efficiency of the technique. The detection limit is estimated to be ~1 ppm .m for NO(2) and 100 ppb.m for NO. The range of measurement is limited to 1 km, due to the strong UV Rayleigh scattering and O(2) absorption.