ELFT HÍRADÓ

[mcsete AT physx.u-szeged.hu]

Meghívó

SZTE TTIK Fizikai Intézet Szemináriuma

Előadó: Professor Markus W. Sigrist
ETH Zürich, Institute for Quantum Electronics, CH-8093 Zürich, Switzerland


Cím: Infrared laser spectroscopy: from trace detection to glucose sensing
Időpont: 2019. 03. 21. (csütörtök), 14-15 h
Helyszín: SZTE TTIK, Fröhlich Pál tanterem,
Szeged, Tisza Lajos körút. 84-86.

Absztrakt:
Chemical sensing and analyses of samples by laser spectroscopic  
methods are attractive owing to several advantages such as high  
sensitivity and specificity, large dynamic range, multi-component  
capability, and lack of pretreatment or preconcentration procedures.
The preferred wavelength range comprises the fundamental molecular  
absorption range in the mid-infrared between 3 and 15 ?m. The  
availability of broadly tunable mid-infrared sources like external  
cavity quantum cascade lasers (EC-QCLs), interband cascade lasers  
(ICLs), difference frequency generation (DFG), optical parametric  
oscillators (OPOs), recent developments of diode-pumped lead salt  
semiconductor lasers, of supercontinuum sources or of frequency combs  
have eased the implementation of laser-based sensing devices.
Sensitive techniques for molecular absorption measurements include  
multipass absorption, various configurations of cavity-enhanced  
techniques such as cavity ringdown (CRD), or of photoacoustic  
spectroscopy (PAS) including quartz-enhanced (QEPAS) or  
cantilever-enhanced (CEPAS) techniques. The application requirements  
finally determine the optimum selection of laser source and detection  
scheme.
After a brief introduction on some key issues, various experimental  
setups and the performance of selected systems for chemical sensing of  
selected atmospheric species will be discussed. Applications include  
an early example of continuous vehicle emission measurements with a  
mobile CO_2-laser PAS system [1], measurements on short-lived species  
like nitrous acid (HONO) with a QCL-based QEPAS system [2], isotope  
measurements in human breath [3], a true analysis of gas mixtures with  
a widely tunable DFG system in a medical application [4], as well as  
the fast analysis of C_1-C_4 alkanes at sub-ppm concentrations with a  
new type of mid-infrared diode-pumped piezoelectrically tuned lead  
salt VECSEL [5].
Finally, a new approach for the non-invasive in vivo detection of  
glucose in the interstitial fluid in the epidermal layer of human skin  
is presented. It is based on QCL absorption of glucose and  
photoacoustic detection with a special PA cell in direct contact with  
skin [6].

1. D. Marinov and M.W. Sigrist: Photochem. and Photobiol. Sciences 2,  
774-778 (2003)
2. H. Yi, R. Maamary, X. Gao, M.W. Sigrist, E. Fertein, and W. Chen:  
Appl. Phys. Lett. 106,     101109 (2015)
3. R. Bartlome and M.W. Sigrist: Opt. Letters 34, 866-868 (2009)
4. M. Gianella and M.W. Sigrist: Appl. Phys. B 109, 485-496 (2012)
5. J.M. Rey, M. Fill, F. Felder and M.W. Sigrist: Appl. Phys. B 117,  
935-939 (2014)
6. J. Kottmann, J. M. Rey and M. W. Sigrist: Sensors 16, 1663 (2016)


Minden érdeklődőt szeretettel várunk.

Dr. Csete Mária
szeminárium-koordinátor

----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.