High resolution spectroscopy and applications
Date
2013
Authors
Povey, Chad A
University of Lethbridge. Faculty of Arts and Science
Journal Title
Journal ISSN
Volume Title
Publisher
Lethbridge, Alta. : University of Lethbridge, Dept. of Physics and Astronomy, 2013
Abstract
With the ever increasing spectral resolution now achievable with modern
spectrometers we do not just observe dark lines anymore but molecular absorption
features at very high resolution. These features are governed by the kinematics of the
molecules and can be examined carefully by using high resolution spectroscopy. A
detailed description of the setup and performance of the tunable diode laser spectrometer
(TDL) system used in my research is presented. This tunable laser system has been used
to complete several high resolution line shape studies on the 1+ 2+ 4+ 5 and 1+ 3
combination bands of acetylene. The major focus of the presented results has been on the
temperature dependence of the retrieved parameters and the identification of the best
fitting line shape profile used in the present investigation.
Improved spectral resolution also requires better understanding of its effects on
the recorded data that could not have been observed on data obtained with low resolution
instruments. One of these effects is known as line mixing and it occurs when
neighbouring transitions interfere with each other causing a slight asymmetry in the
spectral profile. In this Thesis I have examined the line mixing effect in CO2 spectra and
the temperature dependence of these line mixing coefficients. The analysis is performed
by using two common line mixing models; (1) the energy correct sudden approximation
and (2) the exponential power gap law.
Finally I will present a project based on the application of high resolution
spectroscopy that involves monitoring N2O concentration at remote locations through the
use of a long path gas cell and a tunable diode laser spectrometer system. The initial
testing and setup of this monitoring system will be presented and discussed
Description
xlii, 221 leaves : ill. ; 29 cm
Keywords
Spectral resolution , Line mixing , High resolution spectroscopy , Tunable diode laser spectrometer , Absorption spectra , Dissertations, Academic