MIRTHE quantum cascade laser developments among the new
    technologies for remote sensing discussed by EPA

Gerard Wysocki EC-QCLThe U.S. Environmental Protection Agency’s (EPA) Office of Air Quality Planning and Standards, Office of Research and Development, and Office of Solid Waste and Emergency Response sponsored a workshop on “REMOTE SENSING OF EMISSIONS: 2008 New Technologies and Recent Work held on April 1-3 2008. The purpose of the workshop was to discuss the findings of remote sensing studies of emissions from refinery and natural gas operations that had been performed in US, Europe and Canada, as well as to identify new technologies and future applications for remote sensing. Representatives from Canada, Sweden, United Kingdom (UK), EPA, state and local agencies, equipment vendors, consultants, and industry attended the workshop.

Several well established as well as new technologies for remote sensing were discussed during the workshop including differential absorption LIDAR (DIAL), radial plume mapping (RPM) and vertical RPM methods using open path Fourier transform infrared spectrometers (OP-FTIR), differential optical absorption spectroscopy (DOAS), and tunable diode laser spectrometers (TDLS). One of the new technologies that are very promising and offer a significant improvement of today’s instrumentation for environmental open path monitoring is external cavity quantum cascade laser (EC-QCL) technology. The technology was presented at the EPA workshop by Professor Gerard Wysocki from Electrical Engineering Department at Princeton University, who develops EC-QCLs with MIRTHE.
EC-QCLs are novel widely tunable laser sources that operate in the mid-to far-infrared range where molecular rotational-vibrational transitions are the strongest, do not require cryogenic cooling, and can provide high output powers (>100mW). Wide tunability up to 15% of the center wavelength allows for detection of complex molecules with broadband absorption spectra (e.g. Volatile Organic Compounds - VOCs) or for simultaneous multi-species monitoring and quantification. With further increase of the available tuning ranges this technology will offer functionality similar to the well established FTIR instrumentation, while providing significantly higher spectral resolution (<0.001cm-1), higher molecular specificity and improved detection limits.

The Proceedings from the workshop summarizing the technologies discussed as well as suggestions and recommendations for future actions to be taken by the various entities represented at the meeting are available for public access at the EPA Website.