S. Helmfrid et al., Spatial holeburning in second-order excitation probability distribution for densely erbium-doped fibres, ELECTR LETT, 35(14), 1999, pp. 1191-1193
The increase in upconversion rate in strongly erbium-doped fibres induced b
y an enhanced energy redistribution is investigated and explained in terms
of spatial holeburning in the second-order excitation probability distribut
ion. It is shown that the equalisation of decay curves, where the initial p
opulation has been prepared in different ways, is caused by an increased up
conversion rate for closely located excited ions.