<div class="csl-bib-body">
<div class="csl-entry">Lendl, B. (2024, January 24). <i>Advances in mid-IR laser based liquid and gas sensing: New measurement modalities and applications</i> [Presentation]. Theodore Maiman Seminar 2024, Garching, Germany. http://hdl.handle.net/20.500.12708/212232</div>
</div>
-
dc.identifier.uri
http://hdl.handle.net/20.500.12708/212232
-
dc.description.abstract
Mid-infrared (Mid-IR) quantum cascade lasers stand out as coherent and polarized sources, offering rapid intensity and wavelength modulation capabilities. These features enable the development of advanced sensing strategies that extend beyond traditional absorption spectroscopy, which relies on the Beer-Lambert law.
When interacting with gaseous or liquid samples, laser radiation does more than attenuate light intensity; it also induces a phase shift in the transmitted light and heats the sample containing the analyte. While direct absorption spectroscopy primarily exploits intensity attenuation, these additional effects form the basis for dispersion spectroscopy and indirect methods like photoacoustic and photothermal spectroscopies.
This presentation will review potential measurement modalities, highlight recent instrumental advancements, and showcase selected applications. For liquid sensing, we employ broadly tunable external cavity quantum cascade lasers. We demonstrate their use in measuring protein secondary structures in water, exemplified by in-line detection in liquid chromatography and protein melting experiments. Dispersion spectroscopy will be introduced through measuring ethanol in water, illustrating its suitability for dynamic reaction monitoring. This will include observing the enzyme-catalyzed hydrolysis of sucrose into glucose and fructose.
For gas sensing, the presentation introduces Interferometric Cavity-Assisted Photothermal Spectroscopy (ICAPS) as a novel and compact approach for gas analysis. ICAPS utilizes a distributed feedback quantum cascade laser in the mid-IR range, a Fabry-Pérot (FP) cavity, and a NIR probe laser. The target analyte's periodic absorption of mid-IR radiation leads to a modulated refractive index change in the gas matrix due to temperature fluctuations. This occurs within an FP cavity, causing a shift in its transmission function, detectable by a NIR laser passing through the cavity. This method achieves single-digit ppb sensitivities in a total absorption length of just 1 mm, showcasing its high precision and compactness.
en
dc.description.sponsorship
European Commission
-
dc.language.iso
en
-
dc.subject
Optical sensing and sensors
en
dc.subject
Quantum Cascade Laser
en
dc.title
Advances in mid-IR laser based liquid and gas sensing: New measurement modalities and applications
en
dc.type
Presentation
en
dc.type
Vortrag
de
dc.relation.grantno
101119714
-
dc.type.category
Presentation
-
tuw.publication.invited
invited
-
tuw.project.title
Advanced, trustworthy AI and data solutions for individualised automated milking & feeding of dairy cows
-
tuw.researchTopic.id
M2
-
tuw.researchTopic.id
Q1
-
tuw.researchTopic.name
Materials Characterization
-
tuw.researchTopic.name
Photonics
-
tuw.researchTopic.value
50
-
tuw.researchTopic.value
50
-
tuw.publication.orgunit
E164-02-1 - Forschungsgruppe Prozessanalytik
-
tuw.author.orcid
0000-0003-3838-5842
-
tuw.event.name
Theodore Maiman Seminar 2024
en
tuw.event.startdate
24-01-2024
-
tuw.event.enddate
24-01-2024
-
tuw.event.online
On Site
-
tuw.event.type
Event for scientific audience
-
tuw.event.place
Garching
-
tuw.event.country
DE
-
tuw.event.presenter
Lendl, Bernhard
-
wb.sciencebranch
Chemie
-
wb.sciencebranch
Physik, Astronomie
-
wb.sciencebranch.oefos
1040
-
wb.sciencebranch.oefos
1030
-
wb.sciencebranch.value
50
-
wb.sciencebranch.value
50
-
item.languageiso639-1
en
-
item.openairetype
conference presentation
-
item.grantfulltext
restricted
-
item.fulltext
no Fulltext
-
item.cerifentitytype
Publications
-
item.openairecristype
http://purl.org/coar/resource_type/R60J-J5BD
-
crisitem.author.dept
E164-02 - Forschungsbereich Umwelt-, Prozessanalytik und Sensoren
-
crisitem.author.orcid
0000-0003-3838-5842
-
crisitem.author.parentorg
E164 - Institut für Chemische Technologien und Analytik
