The absorption spectrum of α-pinene gas, a biogenic volatile organic compound, was directly measured with a pulsed mid-infrared laser. The maximum absorption wavelength was found to be ~3.42 μm, and an absorption cross section of 4.8 × 10<sup>−23</sup> m<sup>2</sup> molec<sup>−1</sup> was obtained. A simple theoretical calculation with the measured spectral data showed that several hundreds of parts in 10<sup>12</sup> (ppt) of α-pinene gas in forest–mountain areas over a range of ~10 km were detectable by a long-path-averaged hard-target absorption lidar. Requirements for system development were also discussed.
© 2001 Optical Society of America
Yasunori Saito, Petter Weibring, Hans Edner, and Sune Svanberg, "Possibility of Hard-Target Lidar Detection of a Biogenic Volatile Organic Compound, ν-Pinene Gas, Over Forest Areas," Appl. Opt. 40, 3572-3574 (2001)