The Journal of Chemical Physics

Experiments on Er3+ in SrF2. III. Coupled-Ion Effects

M. R. Brown, H. Thomas, James M. Williams, R. J. Woodward, W. A. Shand

Published Oct 15, 1969• 28 citations

Abstract

The pumping intensity and concentration dependences of the fluorescence output from three infrared quantum-counter schemes that involve coupled ions in Er3+-doped SrF2 have been measured at 300 and 77°K. The pumping intensity depended linearly on the numbers of photons absorbed in the schemes. The power of the concentration dependence was found to be noninteger in the range 1%–10%. This has been interpreted as indicating the importance of energy migration between the Er3+ ions as mechanism for populating the energy levels of the coupled ions.

DOI: 10.1063/1.1672514

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The Journal of Chemical Physics

Experiments on Er3+ in SrF2. III. Coupled-Ion Effects

M. R. Brown, H. Thomas, James M. Williams, R. J. Woodward, W. A. Shand

Published Oct 15, 1969• 28 citations

Publisher

Abstract

DOI: 10.1063/1.1672514

Related papers

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Laser PhysicsJan 28, 20154 citations

The fluorescence intensities and lifetimes of various no-phonon lines in ruby samples with 2.1 and 0.94%

{\mathrm{Cr}}^{3+}

were studied from 13 to 700\ifmmode^\circ\else\textdegree\fi{}K. The temperature dependences of the intensities of numerous lines were used to determine the energy levels of two pair systems. The relative intensities of the single-ion (

R

) lines and the pair (

N

) lines are proportional to Boltzmann factors ${e}^{\frac{\ensuremath{-}\ensuremath{\Delta}E}{\mathrm{kT}}}$, where $\ensuremath{\Delta}E$ is the difference in energy of the metastable states, at high temperatures but not at low temperatures. The deviation from this law is greater and occurs at higher temperatures in the less concentrated sample. The fluorescence decays of the

R

and

N

lines are pure exponentials in the temperature region where the

N

lines follow a Boltzmann law; at low temperatures the

N

lines have an initial rise in fluorescence and then a decay. These results are interpreted in terms of coupled fluorescence systems consisting of single ions and pairs. A phonon-assisted cross-relaxation coupling process is suggested which allows for thermalization of the systems at high temperatures and direct pumping of the pair systems by the single-ion system at low temperatures. Energy transfer from single-ion to multi-ion systems was also observed.