Faculty Candidate Seminar - Gerard Wysocki

03/16/2016 - 2:00pm
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DATE:     March 16th

LOCATION:  2:00pm in Hubbs Hall 4500 (SIO)
SPEAKER: Gerard Wysocki, Ph.D.
Princeton University

TITLE:   Novel spectroscopic sensing technologies for environmental, bio-medical and industrial applications

Laser spectroscopy is a powerful technology for non-invasive chemical detection and plays an important role in numerous applications including environmental monitoring, industrial emission control, biomedical sensing, security and safety applications etc.. In this talk I will present examples of novel spectroscopic techniques developed in my laboratory for sensitive detection of trace gases in various real-world applications.
Radical species play an important role in many chemical processes ranging from atmospheric chemistry (e.g. ground ozone formation), bio-medical science, to combustion. These highly reactive chemical species usually occur at relatively low concentration levels, and remain difficult to quantify in experiments. Faraday rotation spectroscopy (FRS) leverages magneto-optical properties of paramagnetic species, which allows achieving high selectivity even in the presence of strong spectral interference from highly abundant diamagnetic species (such as H2O or CO2). I have developed novel FRS spectrometers that allow performing measurements of radical species with sensitivities approaching the fundamental quantum limits of optical detection. Examples of FRS isotopic detection for environmental nitrogen cycle studies, bio medical applications in breath analysis, and sensitive measurements of radical species in combustion diagnostics will be discussed. 
Another unique technology platform developed in my laboratory is a new class of laser spectroscopic methods that retrieve chemical information by probing optical dispersion in the vicinity of molecular transitions. In contrast to conventional absorption-based techniques these new molecular dispersion spectroscopy provide unique measurement capabilities and enable new applications in chemical detection. Fundamentally the optical dispersion measurement probes phase of the light wave interacting with the measured sample, which results in high immunity to optical intensity fluctuations, and extends dynamic range of concentration measurements. In this talk I will provide an overview of recently developed chirped laser dispersion spectroscopy (CLaDS) that is ideally suited for remote chemical sensing in a remote LIDAR configuration. Several prototype instruments utilizing the dispersion spectroscopy techniques in the mid-infrared (using quantum cascade lasers) and in the near-infrared will be presented.
Faculty Hosts:    John Hildebrand (jhildebrand@ucsd.edu) & George Papen (gpapen@ucsd.edu)
For more information on this event, contact: 
Leslie Costi
Event Calendar: 
Hubbs Hall 4500