Upconversion Detection for Improved Nonlinear Mid-infrared Spectroscopy in Flames
Författare
Summary, in English
The main focus has been on investigating the new opportunities that upconversion detection makes possible. It had already been demonstrated that upconversion greatly improved the sensitivity of DFWM. As a part of this thesis work, it was shown that signal to noise ratio of IRPS was also improved by upconversion, although not to the same degree.
DFWM with upconversion was used to quantitatively measure HCN released during the devolatilization phase of burning straw pellets, which was only possible due to the improved sensitivity of the detection system. A major part of quantifying concentration measurements is achieving accurate temperature measurements, as the signal scales with temperature. A method of measuring temperature using the relative strength of transition lines of water had been described before this thesis. The effects of signal saturation for waterline thermometry were investigated as part of this thesis to increase the precision
and reliability of temperature measurements, as this would aid in achieving more accurate concentration measurements.
Avdelning/ar
Publiceringsår
2019-11
Språk
Engelska
Fulltext
Dokumenttyp
Doktorsavhandling
Förlag
Department of Physics, Lund University
Ämne
- Atom and Molecular Physics and Optics
Nyckelord
- infrared
- upconversion
- degenerate four wave mixing
- hydrogen cyanide
- polarisation spectroscopy
Status
Published
Handledare
ISBN/ISSN/Övrigt
- ISSN: 1102-8718
- ISBN: 978-91-7895-250-2
- ISBN: 978-91-7895-249-6
Försvarsdatum
17 december 2019
Försvarstid
09:15
Försvarsplats
Lecture hall K404, building of Physics, Sölvegatan 14, Faculty of Engineering LTH, Lund University, Lund.
Opponent
- Juha Ilmo. Toivonen (Prof.)