Optical spectroscopy of borate glasses, doped with europium

The high optical quality glasses with Li
₂
B
₄
O
₇
:Eu, CaB
₄
O
₇
:Eu, and LiCaBO
₃
:Eu compositions containing 0.5 and 1.0 mol. % Eu
₂
O
₃
have been obtained by standard glass technology. Using electron paramagnetic resonance (EPR) and optical spectroscopy it was shown that the Eu impurity is incorporated into the Li
₂
B
₄
O
₇
, CaB
₄
O
₇
, and LiCaBO
₃
glasses network as Eu
³⁺
(4f
⁶
,
⁷
F
₀
) ions, exclusively. All observed f - f transitions of the Eu
³⁺
centres in optical absorption, luminescence excitation and emission spectra were identified. Luminescence kinetic shows single exponential decay with different lifetimes for Eu
³⁺
centres in the Li
₂
B
₄
O
₇
, CaB
₄
O
₇
, and LiCaBO
₃
glasses.