EFFECT OF DROPLET-INDUCED BREAKDOWN ON CARS TEMPERATURE-MEASUREMENTS

This research examines the potential for coherent anti-Stokes Raman scattering (CARS) to provide reliable gas temperature measurements in the presence of liquid droplets. The droplets cause dielectric breakdown by focusing the CARS laser beams. This breakdown produces a plasma that can disrupt or obscure the CARS signal. Specifically, we examine the influence of laser induced breakdown on the CARS signal, and we determine the importance of droplet position relative to the CARS focal volume and droplet concentration on the reliability of CARS temperature measurements in droplet-laden flows. In addition, we propose a reliable data reduction procedure to minimize the disruptive influence of laser induced breakdown on CARS temperatures. © 1990 Optical Society of America.