AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Optical Trap and Laser Spectroscopy for Characterizing Single Airborne Aerosol Particles
YONG-LE PAN, Chuji Wang, Joshua Santarpia, US Army Research Lab.
Abstract Number: 347 Working Group: Single Aerosol Particle Studies - Techniques and Instrumentation
Abstract There is a need for improved real-time on-line instruments for studying and monitoring aerosols, especially bio- and chemical threats. Although some spectra-based technologies (mass, fluorescence, laser-induced-breakdown) have been developed, other technologies, e.g. Raman and absorption spectra can provide more information for better discrimination, but its signal is extremely weak from a single micron-sized aerosol particle. Collecting adequate spectra from individual single micron-sized particle requires measurement time of at least seconds. Therefore, combining optical trap and other laser spectroscopic technologies to allow better characterizing individual single particles and studying time evolution phenomena is highly desired. Here, we use our recently developed laser trapping setup, which allows us to trap either absorbing or transparent particles in air, and various laser diagnostic technologies to obtain elastic scattering pattern in the back and near back scattering direction, fluorescence spectra, Raman spectra, and cavity ring-down spectra (CRDS). Using these methods, the information about a single particle’s morphology, vibrational transitions, and extinction efficiency are, for the first time, obtained from a few trapped bioaerosol aerosol particles in air.
This research was supported by the Defense Threat Reduction Agency (DTRA) and ARL mission funds.