Tellurite And Fluorotellurite Glasses For Active And Passive

6. Optical properties; MDO 191
Absoprtion coefficient / cm -1
120
110
100
90
80
70
60
50
40
30
20
10
Wavelength / µm
13 12 11 10 9 8 7 6
MOD013: 80TeO 2 -10Na 2 O-10ZnO
2.98 mm
0.50 mm
0.20 mm
0
750 1000 1250 1500 1750
Wavenumber / cm -1
Fig. (6.13): Infrared spectra in the mid- and far-infrared regions for glasses of
composition MOD013 (80TeO2-10Na2O-10ZnO mol. %), performed on samples of
thickness, 2.98, 0.50 and 0.20 mm.
From fig. (6.13), it can be seen that the region where spectra were to be collected before
the signal become too noisy (i.e. the detector was underloaded), was extended with
decreasing thickness of the sample. For the 2.98 mm sample the spectra extended to
around 1520 cm -1 (6.58 µm), for 0.50 mm to around 920 cm -1 (10.87 µm), and for 0.20
mm to around 850 cm -1 (11.76 µm). Absorption bands within the multiphonon edge
become more easily discernable with decreasing thickness of sample. Fig. (6.14), the
bands seen in the multiphonon edge are seen for the 0.20 mm sample.