Princeton Docket #
10-2584-1
Researchers
from Princeton University and the
STFC Rutherford Appleton Laboratory (UK) have developed a novel method of high
sensitivity molecular detection based on detection of refractive index changes
around the absorption line. This
method employs heterodyne interferometric measurement with a frequency chirped
laser source and offers high enhancement of the weak dispersion signal, which
enables sensitive molecular quantification. It has been shown experimentally that
this method is almost immune to laser power variation (by several orders of
magnitude), or intensity noise, which is particularly attractive feature for
applications under strongly changing optical transmission conditions (e.g. long
path remote sensing, turbulent environments, smoke stacks, etc.).
Laser
absorption spectroscopy (LAS) based on tunable semiconductor lasers and/or
non-linear frequency conversion sources have become a widely used technique for
the analysis of gas-phase chemicals. Applications cover a broad range of
sectors including industry, atmospheric monitoring and medicine. Most of the LAS techniques rely on
probing the absorption signal characteristic to a gas sample and are
fundamentally limited to the measurement of small signal changes (absorption) on
the top of a large background (total light intensity arriving at the detector),
which may limit the dynamic range of the acquisition system. Therefore, direct absorption
measurements are strongly affected by the fluctuations of laser power reaching
the detector.
Application
Trace-gas sensing,
particularly suitable for applications
under strongly changing optical transmission
conditions
Advantages
·
High
immunity to laser power variation
·
Virtually
background free
·
Stabile
operation
Publication
G.
Wysocki, D. Weidmann. Molecular dispersion spectroscopy for chemical sensing
using chirped mid infrared quantum cascade laser. Optics Express 18, 25,
26123-26140 (2010).
Inventors
Gerard Wysocki is an assistant professor of
Electrical Engineering at Princeton University. His current
research interests focus on the development of novel laser-based spectroscopic
systems for chemical sensing in various applications including environmental
monitoring, bio-medical research, and industrial process control. Among many distinguished awards most
recently Professor Wysocki has been named finalist of the Blavatnik Awards for
Young Scientists (2011), received NSF Early Career Award (2010), Masao Horiba
Award (2010, Japan), and NASA Tech Brief Award for Scientific or Technical
Innovation (2010).
Damien Weidmann is
Laser
Spectroscopy team leader in the Space Science and Technology Department of the
Rutherford Appleton Laboratory in UK. Dr. Weidmann¿s research interests
cover the area of high-resolution tuneable laser spectroscopy for remote and
in‐situ molecular sensing as well as the development of corresponding
instruments and applications.
Intellectual Property status
Patent
protection is pending.