Abstract
Novel zinc borate glass doped with mixed rare-earth ions such as erbium (Er
3+
) and ytterbium (Yb
3+
) ions were prepared by conventional melt annealing process. The structural glass network comprised units of ZnO
4
, triangle borate (BO
3
), tetraborate (BO
4
), and B–O–B and B–O–Zn bridges. The glass density (
ρ
) values increased from 3.490 to 3.573 g/cm
3
, when the Yb content increased from 0.2 to 1.0 mol%. The optical transition values decreased from 3.076 eV to 2.936 eV as the Yb
3+
ions increased from 0.2 to 1.0%. Judd–Ofelt theory is used to analyze the spectroscopic properties of the glass. The intensity parameter
Ω
2
has higher values than
Ω
4
and
Ω
6
indicating to the covalent character of the glass. The calculated radiative lifetime
τ
r
for the glass containing 1.0% Yb
2
O
3
sample has the lowest value around 25 μs. The absorption cross section
σ
a
λ
intensity increased from
1.632
×
10
-
20
to
∼
1.9
×
10
-
20
cm
−2
where the Yb content increased from 0.2 to 1.0 mol%, whereas the emission cross section
σ
e
λ
of the 0.8 Yb sample has the highest value at
1
×
10
-
19
cm
−2
.