Abstract

Laser remote sensing techniques for detecting trace level atmospheric pollutants have made rapid advances in the past several years.^1,2 Molecular CO₂ lasers play an important role in atmospheric pollution monitoring, because its emission spectrum in the 9-11 μn range falls within the largest atmospheric window and which overlap with the absorption spectra of a large number of molecules of environmental concern.² The primary pollutants that are emitted to the atmosphere by natural and anthropogenic processes are, hydrocarbons (HC), carbon oxides (CO, CO₂), nitric oxides (NO, NO₂), ammonia (NH₃), sulfur dioxide (SO₂), and etc.³ The primary pollutants also go through complex chemical reactions among themselves or with the natural atmospheric constituents, to form a variety of secondary pollutants.^2,3 An understanding of the atmospheric chemical processes requires fast detection of primary and secondary pollutants while they reside in the atmosphere. Laser remote sensing techniques are suitable for the detection of these pollutants.

© 1994 Optical Society of America