This project addresses the need for the development of field deployable, sensors which provide real-time quantitative measurements of Volatile Organic Compounds - airborne pollutants that are injurious to human health. In this particular case, benzene, formaldehyde and 1,3-butadiene. These three compounds have been identified as top cancer risk air pollutants The proposed program, a collaborative effort between Princeton Technology Advisers Company, Inc. (a small business) and Princeton University Laser Sensing (PULSe) group at Mid-Infrared Technologies for Health and Environment (MIRTHE) - NSF Engineering Research Center at Princeton University, will involve the design, construction, validation and testing of portable mid-IR VOC sensing LIDAR (LIght Detection And Ranging). The LIDAR is based upon two major innovations: 1) Multi-component chemical analysis will be enabled thorough application of novel mid-IR widely tunable external cavity quantum cascade lasers with mode-hop-free high resolution wavelength tuning capability. 2) Significant enhancement of the optical detection will be achieved through coherent optical heterodyne sensing, which will provide shot-noise limited sensitivities. This will allow for improved detection distances, back-scattering from natural topographic features and most importantly application of less sensitive thermoelectrically cooled mid-IR detectors. The LIDAR to be developed will provide high sensitivity, specificity and fast time response superior to instruments that employ more conventional techniques. The target LIDAR system will be batteries operated for at least 8 hours before recharging and will be comparable in weight and size to a camcorder. During Phase II of this program, the field-deployable prototypes of the gas sensing LIDAR will be built. It will additionally incorporate GPS and wireless transceiver to provide real time data output which can be collected using a WiFi network. Extensive field testing will be conducted.
Gas sensing LIDARs will be used by the air pollution research and environmental health community to monitor point-of contact exposure to VOCs. They can also be deployed in manufacturing facilities that are subject to occupational health and safety regulations. Long-time stationary deployments can also be used for toxicology studies over extended time periods.
