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Non-Linear Near-Infrared Spectroscopy Concepts for Remote Sensing


EMSL Project ID
42193

Abstract

Linear forms of LIDAR, such as fluorescence or FM-DIAL, have proved ineffective for remotely detecting low concentration or otherwise transient compounds in the atmosphere, especially under standard conditions of atmospheric pressure and moderate humidity (> 30 %). Published theoretical proposals by Prof. Marlan Scully's group suggest ultra-fast nonlinear stimulated emission Lidar concepts can better detect molecules before collisional broadening, internal energy exchange and reactions diminish their net output signal.1-3 Scully's techniques induce efficient backscatter in a highly directional return beam that avoids radiative losses to all 4-pi steradians. They propose ultra-fast (sub-picosecond) VIS/UV lasers to induce coherent transients (CTs) to avoid large signal losses like hydrolysis, collisional relaxation, etc., that occur near the earth's surface. We have reviewed these ideas and consider that several simpler concepts of inducing highly directional backscattered CTs would also work and, importantly, could probably be implemented without using the proposed ultra-fast (sub-picosecond) stimulation to proceed.

Project Details

Start Date
2010-08-16
End Date
2013-08-25
Status
Closed

Team

Principal Investigator

Thomas Blake
Institution
Pacific Northwest National Laboratory

Team Members

Alan Joly
Institution
Pacific Northwest National Laboratory

James Kelly
Institution
Pacific Northwest National Laboratory