The Effect of Nd
3+
Composition on Judd-Ofelt Analysis of Lithium
Niobate Tellurite Glasses Codoped with Er
3+
Nurhafizah Hasim
1,a
, Md Supar Rohani
1,b*
1
Advanced Optical Material Research Group, Department Of Physics, Faculty of Science,
Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, Malaysia
a
nurhafizah1989@gmail.com,
b
mdsupar@utm.my
Keywords: Absorption, Oscillator strength, Judd-Ofelt parameters, Luminescence
Abstract. The modification of absorption characteristics in rare-earth doped tellurite glasses is
important in photonics application. The Er
3+
/Nd
3+
co-doped glasses of the form (69-x)TeO
2
–
15Li
2
CO
3
–15Nb
2
O
5
–1Er
2
O
3
-(x)Nd
2
O
3
with x =0.2 and 0.6 mol% are successfully prepared using
conventional melt-quenching technique. The Judd-Ofelt analysis is to determine the local structure
and bonding in the vicinity of rare-earth ions. The oscillator strengths are calculated from the
absorption spectra and used to evaluate Judd-Ofelt intensity parameters (
, =2, 4 and 6). The
enhancement or decrement values of
4
and
6
with the increase of Nd
3+
concentration is ascribed
to the change in glass network structures. The values of
2
are increased from 1.53 to 37.13
( 10
-22
) cm
2
with the increase of Nd
3+
concentration which indicate an increase in the covalent
nature of Nd-O bond and less centrosymmetrical of the ion sites. The decrease in
rad
for each level
with the increase of Nd
3+
concentration signifies on how fast a particular level gets depopulated.
The values of
for the transitions
4
G
5/2
,
2
G
7/2
→
4
I
9/2
,
2
H
11/2
→
4
I
9/2
and
4
F
9/2
→
4
I
9/2
are found to
lie in between 99.6 to 100.0%.
1. Introduction
Lately, optical behavior of rare-earth (RE) doped tellurite based glasses have been studied
thoroughly on optical absorption and decay measurements. This interesting hosts are used due to
their remarkable characteristics and applications on solid state lasers, solar concentrators, optical
detectors, waveguide lasers, optical fibers for telecommunication and opto-electronics devices [1-2].
Moreover, tellurite glasses possess good chemical durability, good thermal and mechanical stability,
high refractive index, good transparency in mid-infrared region (0.36-6 µm), low phonon energy
(700-800 cm
-1
), low melting temperature, high linear and nonlinear refractive index, excellent
transmittance in visible and near-infrared region, wide transmission window (0.4-6 µm) and high
solubility for RE ions [3-4].
Among many RE ions, Er
3+
is an ideal luminescent center for visible-mid-infrared emission
processing several efficient transitions
2
H
11/2
→
4
I1
5/2
,
4
S
3/2
→
4
I1
5/2
,
4
F
9/2
→
4
I
15/2
and
4
S
3/2
→
4
I
13/2
[4 where it can easily be optically pumped but the efficient enhanced emissions cross-section are far
from being achieved. To improve from this shortcoming, addition secondary RE ions, Nd
3+
is the
most efficient candidates for photonic devices. Recently, researcher has been focusing in near-
infrared spectra range from 800-1500 nm where Nd
3+
ions display the emission at 898, 1070 and
1338 nm originating from electronic transitions between
4
F
3/2
→
4
I
9/2
,
4
F
3/2
→
4
I
11/2
and
4
F
3/2
→
4
I
13/2
,
respectively [3-4]. Previously, the optical properties of tellurite glasses can be modified by doping
them with either Er
3+
[5] or Nd
3+
[6] but there are no systematic studies made on codoped in lithium
niobate tellurite glass. Therefore, the present work intended to inspect the influence of codoped on
the optical properties of this glass system to determine the feasibility of solid state laser applications
and the development of lasers and amplifiers [7-8].
Judd-Ofelt theory has been applied to estimate important spectroscopic properties of RE doped
glasses by many researchers [9-11]. This theory also determines the probability of forced electric
Solid State Phenomena Submitted: 2016-10-20
ISSN: 1662-9779, Vol. 268, pp 191-197 Revised: 2017-05-18
doi:10.4028/www.scientific.net/SSP.268.191 Accepted: 2017-07-06
© 2017 Trans Tech Publications, Switzerland Online: 2017-10-17
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