Nonradiative decay processes and mechanisms of frequency upconversion of Er3+ in ZrF4–BaF2–LaF3 glass

Abstract

We have investigated the decay processes of the Er:4S3/2 and F39/2 states and the mechanisms of frequency upconversion under 800 nm excitation of Er3+ in ternary ZrF4–BaF2–LaF3 glasses. The decay processes of the Er:4S3/2 and F49/2 states are discussed on the basis of the Er concentration dependence of the fluorescence lifetime. The quantum efficiencies of emission of the S43/2 and F49/2 states are 73% and 25%, respectively. The difference in the quantum efficiencies between these states can be explained from the difference in the multiphonon decay rates: the multiphonon decay rate of the S43/2 state is much smaller than that of the F49/2 state. The multiphonon relaxation is a dominant nonradiative decay process of the F49/2 state. A dominant nonradiative decay process of the S43/2 state is self-quenching at high Er concentrations. The upconversion mechanisms under 800 nm excitation are also investigated from the dependence of upconversion luminescence on excitation wavelengths (800 and 980 nm), excitation laser power, and Er concentration. The mechanism of upconversion from 800 to 660 nm is mainly due to the energy transfer between the I49/2→4I13/2 and F49/2←4I11/2 transitions. We also show that the upconversion from 800 to 550 nm is due to excited-state absorption.

Spectral variations and energy transfer processes on both Er3+ ion concentration and excitation densities in Yb3+–Er3+ codoped LaF3 materials

“…By excitation of laser in near-infrared wavelength region, all kinds of up-conversion emissions and various energy-transfer processes [1][2][3] have been presented and investigated. Furthermore, the realization of Yb 3+ -sensitized mechanism has made up-conversion efficiency of Yb 3+ -Er 3+ codoped materials improved greatly [4] and the cross-relaxation processes on a single type of Er 3+ ions [5][6][7][8] with a more efficient up-conversion luminescence have been shown in codoped system. More recently, a detailed review involving Er 3+ on up-conversion processes in solid has been reported by Auzel [9].…”

Up-conversion luminescence of erbium (III) oxalate nanoparticles/titania/ÿ-glycidoxypropyltrimethoxysilane composite sol-gel thin films

“…Hence this wavelength has been chosen as attractive pump wavelength as has been done earlier in other host matrices previously. [18][19][20][21] The dependence of the up-conversion intensity of the composite film with 2 wt.% erbium oxalate content upon baking temperature was examined and the results are depicted in Fig. 7.…”

Investigação de Er3+ nos dois sítios cristalográficos de Gd2SiO5 através da fotoluminescência resolvida no tempo

“…Neste caso, quanto maior a concentração de íons Er 3+ , maior é a probabilidade de interação entre os mesmos podendo haver transferencia de energia entre eles e assim, o surgimento de um novo meio de decaimento do estado excitado que contribui com uma diminuição no tempo de vida. Esta dependência do tempo de vida do estado 4 S 3/2 com a concentração de Er 3+ é descrita, por exemplo, por Takahashi et al 18 . Um ajuste linear tanto das curvas correspondentes ao sítio 1 (Figs.…”