Tellurite And Fluorotellurite Glasses For Active And Passive

6. Optical properties; MDO 217
It can be seen that the bands due to Er +3 shifted to lower wavenumber with increasing
temperature. The underlying structure of the bands also became more distinct with
increasing temperature.
Fig. (6.45) shows the near-IR spectra of glass MOF017 (69.86TeO2-9.98Na2O-
19.96ZnF2-0.20ErF3 mol. %) heat treated for 1, 5 and 11 hours at 240°C.
Absorption coefficient / cm -1
0.11
0.10
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0.00
Wavelength / µm
1.60 1.55 1.50 1.45
6200 6400 6600 6800 7000
Wavenumber / cm -1
1hr. 240 o C
5hr. 240 o C
11hr. 240 o C
Fig. (6.45): Near-IR spectra of glass MOF017 (69.86TeO2-9.98Na2O-19.96ZnF2-
0.20ErF3 mol. %) heat treated for 1, 5 and 11 hours at 240°C.
It can be seen that the band intensity decreased with increasing temperature, however the
shape did not change significantly.
Fig. (6.46) shows the visible spectra of glass MOF017 (69.86TeO2-9.98Na2O-
19.96ZnF2-0.20ErF3 mol. %), untreated, and heat treated 1 hour at 245 and 255°C.
110
100
90
80
70
60
50
40
30
20
10
0
Loss / dB.m -1