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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

International Conference and Exhibition on

Lasers, Optics & Photonics

Quartz-enhanced photoacoustic spectroscopy with electrical co-excitation

Ulrike Willer, Mario Mordmueller

and

Wolfgang Schade

Clausthal University of Technology, Germany

hotoacoustic spectroscopy relies on the temporally modulated energy input into a gas via absorption and the subsequent transfer

into a sound wave that is measured. This transfer of energy from vibrational into translational modes is highly dependent on

collision partners and linked relaxation rates. For quartz-enhanced spectroscopy (QEPAS) a micro-tuning fork is used as a transducer

instead of a conventional microphone and the modulation of the excitation laser is done at the resonant frequency of the tuning fork

for signal enhancement. However, it is not only possible to drive the tuning fork into oscillation by the photoacoustically generated

acoustic wave but also by applying a modulated voltage. With these two different driving forces, either applied simultaneously or

subsequently, it is possible to gain more insight of the properties of the gas and the relaxation dynamics. This is especially valuable if

the background gas and with it the collision partners, density, velocity of sound and relaxation rates change and a variation in signal

cannot unambiguously attributed to a variation in concentration. It will be discussed how the photoacoustic interaction can be used

to promote an originally electrically induced tuning fork oscillation or to fasten its fading, which enables the measurement of times

rather than intensities.

Biography

Ulrike Willer has studied Physics at Christian-Albrechts University in Kiel and completed her PhD in the year 2001 at Clausthal University of Technology, Germany. She

is Researcher at the Energy Research Center and Clausthal University of Technology. She has published more than 45 papers in reputed journals and has been serving

as Progam Comittee Member for different scientific conferences. Her main research interest focuses on mid-infrared spectroscopy, photoacoustics and sensor design.

ulrike.willer@tu-clausthal.de

Ulrike Willer et al., J Laser Opt Photonics 2017, 4:4 (Suppl)

DOI: 10.4172/2469-410X-C1-017