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conferenceseries .com
Volume 4, Issue 4 (Suppl) J Laser Opt Photonics, an open access journal
ISSN: 2469-410X Optics 2017
November 15-17, 2017
November 15-17, 2017 | Las Vegas, USA
8th International Conference and Exhibition on
Lasers, Optics & Photonics
New developments in quartz enhanced photoacoustic sensors exploting custom quartz tuning forks
Vincenzo Spagnolo
Technical University of Bari, Italy
Trace gas detection has a significant impact on a wide range of applications, such as environmental or industrial monitoring or
medical breath analysis. Techniques based on optical absorption offer fast responses, minimal drifts and high gas specificity.
Quartz enhanced photoacoustic spectroscopy (QEPAS) is one of the most sensitive optical techniques for trace gas measurements.
QEPAS exploits a quart tuning fork (QTF) as a resonant optoacoustic transducer that converts the acoustic wave into the electrical
signal via the piezoelectric effect. For more than a decade since its first demonstration in 2002, all the QEPAS systems employed
standard 32 KHz QTFs, similar to the ones incorporated in clock watches and smartphones. Recently, new designs for the QTFs have
been proposed and implemented in QEPAS sensors, opening the way to the use of QTF overtone vibrational modes and novel micro-
resonator configurations providing excellent results in terms of sensitivity. The implementation of custom QTFs also allow extending
the use of QEPAS in the THz spectral range and with laser sources having poor beam profile, like fiber-amplified lasers. Here it will
presented a review of recent results obtained exploiting custom QTFs in QEPAS trace-gas sensors operating in the near-IR mid-IR
and THz ranges. Finally, new QEPAS approaches exploiting simultaneous excitation of the two antinodes of the QTF first overtone
mode or both fundamental and first overtone mode antinodes will be reported. In particular, the latter approach leads to the first
simultaneous dual-gas detection with a QEPAS sensor.
Biography
Vincenzo Spagnolo received his Phd in Physics, in 1994 from University of Bari. Since January 2004, he has been working at the Technical University of Bari, formerly as
Assistant Professor of Physics and since 2015 as Associate Professor. He is the Director of the joint-research lab Polysense created by Thorlabs GmbH and Technical
University of Bari. His current research interests include quantum cascade lasers, fiber optics and optoacoustic gas sensing. His research activity is documented by more
than 160 Scopus publications and two filed patents. He has given more than 40 invited presentations.
Vincenzo Spagnolo, J Laser Opt Photonics 2017, 4:4 (Suppl)
DOI: 10.4172/2469-410X-C1-017