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Spectroscopy and excitation dynamics of the trivalent lanthanides Tm(3+) and Ho(3+) in LiYF4A detailed study of the spectroscopy and excitation dynamics Tm3+ and Ho3+ in yttrium lithium fluoride, LiYF4 (YLF), has been done. Absorption spectroscopy is utilized in the Judd-Ofelt theory to determine radiative transition rates of spontaneous emission. Luminescence spectroscopy is studied under cw diode laser excitation at 785nm. The effect of dopant ion concentration and excitation power on the observed luminescence are considered in these measurements. An analysis of these measurements have been used to determine channels of energy transfer between Tm3+ and Ho3+ ions. The temporal response of Tm and Ho in singly and co-doped YLF to pulsed laser excitation with a Ti:Al2O3 laser and a CoMgF2 laser turned to various wavelengths have also been studied. The energy transfer mechanisms of cross relaxation, upconversion, and resonant energy transfer between Tm3+ and Ho3+ ions have been modeled, and the model parameters extracted by a fitting procedure to the measured temporal response curves. Rate equation approaches to modeling are presented that result in predictions of rate constants for energy transfer processes, as well as more conventional approaches to modeling such as the Forster-Dexter models, which give the interaction strengths in terms of microscopic interaction parameters.
Document ID
19960001909
Acquisition Source
Legacy CDMS
Document Type
Thesis/Dissertation
Authors
Walsh, Brian M.
(Boston Coll. Chestnut Hill, MA, United States)
Date Acquired
September 6, 2013
Publication Date
August 1, 1995
Subject Category
Solid-State Physics
Report/Patent Number
NASA-CR-4689
NAS 1.26:4689
Accession Number
96N11917
Funding Number(s)
CONTRACT_GRANT: NAG1-955
PROJECT: RTOP 233-01-03-08
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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