University of Illinois Urbana-Champaign

Diatomic excimer dynamics in microplasma lamps and alkali lasers

Park, Sehyun

Content Files
PARK-DISSERTATION-2019.pdf

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https://hdl.handle.net/2142/106485

Description

Title
Diatomic excimer dynamics in microplasma lamps and alkali lasers
Author(s)
Park, Sehyun
Issue Date
2019-12-05
Director of Research (if dissertation) or Advisor (if thesis)
Eden, James Gary
Doctoral Committee Chair(s)
Eden, James Gary
Committee Member(s)
  • Cunningham, Brian T
  • Li, Xiuling
  • Lorenz, Virginia
  • Curreli, Davide
Department of Study
Electrical & Computer Eng
Discipline
Electrical & Computer Engr
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Date of Ingest
2020-03-02T22:38:56Z
Keyword(s)
  • Excimer
  • Microplasmas
  • Alkali laser
  • Mercury ion
  • Helium molecule
  • Cs-Rg
Abstract
The dynamics of diatomic excimers - electronically excited molecules having dissociative ground states - generated in alkali-rare gas mixtures and low temperature microplasmas have been pursued and the experimental and computational results are presented here. This work focuses on the Cs-rare gas and He2 molecules that are of considerable interest as efficient near-infrared lasers, or as the energy source for driving the Hg+ vacuum-ultraviolet lamp (194.2 nm). The photoassociation and subsequent stimulated emission of cesium (Cs) - rare gas (Ar or Xe) pairs were examined by laser pump-probe experiments, and an optical-to-optical energy conversion efficiency of ~28% was observed when Cs-Ar pairs were pumped at 836.7 nm and stimulated emission occurs at 852.2 nm. By comparing full quantum simulations of Cs-Xe photoassociation to the gain spectrum of Cs-Xe in the red satellite of the Cs D2 line, it is shown that the structure of weakly bound Cs-Xe molecules (including the dissociation energy), correlated with Cs(62P3/2) + Xe(5p6 1S0) in the separated atom limit, can be determined with precision. Extensive studies of time-resolved emission from the Hg+ ion in electrically driven microplasma lamps show that the Hg+ line at 194.2 nm is pumped efficiently by Penning ionization of the Hg atom by metastable helium molecules. Experimental results as well as zero-dimensional kinetic simulations support the validity of the proposed kinetic pathway.
Graduation Semester
2019-12
Type of Resource
text
Permalink
http://hdl.handle.net/2142/106485
Copyright and License Information
Copyright 2019 Sehyun Park

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