A. Bastidas¹, E. Rodríguez¹, F. Racedo N¹, J. León¹, M. Jaramillo² and E. Solarte³

¹Optics and Laser Group; Dept. of Physics, Universidad del Cauca / Popayán - Colombia
²Cleaner Production Group; Pontificia Universidad Javeriana / Cali - Colombia
³Quantum Optics Group; Dept. of Physics, Universidad del Valle / Cali – Colombia

Atmospheric Lidar systems usually have design configurations that are appropriate to the particle characteristics of the pollutant type present in the region of interest. In this work, a system designed to measure physical properties of aerosol pollutants over the Popayán, (Colombia, North Latitude 2° 27’ and Longitude 76° 37’ Greenwich West), area is presented. The expected pollutant particles and gases are mainly originated by the medium-level volcanic activity of the volcano system surrounding the city, and those generated by internal combustion engines. We have designed a coaxial- monostatic Lidar configuration that uses a 1 W Argon CW laser chopped with a pockels cell extra cavity, @ 514.5 and 488 nm, as the primary light source. The light receiver optics, to collect back-scattered photons, consists of a 6 inches Celestron telescope with high-efficiency refractive optics and a narrow-band interference filter, placed near to the focal point. The collected light is led to the detection stage via an optical fiber. A PMT, model 9818QB, with pulse forming electronics attached to a time discriminator and a pulse counter, converts the optical signal into an electric one, and allows intensity analysis. The measured signals are digitized and stored in a PC.