Tellurite And Fluorotellurite Glasses For Active And Passive

6. Optical properties; MDO 190
Absorption coefficient / cm -1
2.00
1.75
1.50
1.25
1.00
0.75
0.50
0.25
0.00
Wavelength / µm
6 5 4 3 2
2000 3000 4000 5000 6000
Wavenumber / cm -1
(90-x)TeO 2 -xZnO-10Na 2 O
MOD007 (12 mol. % ZnO)
MOD013 (10 mol. % ZnO)
Fig. (6.12): Infrared spectra of glass of the series (90-x)TeO2-10Na2O-xZnO, for x = 12
mol. % (MOD007) and x = 10 mol. % (MOD013).
Again, the multiphonon edge for these glasses occurred at around 1667 cm -1 (6 µm) and
hydroxide (OH) bands occurred at around 3000 cm -1 (3.33 µm) and 2270 cm -1 (4.41 µm).
Fig. (6.13) shows the infrared spectra in the mid- and far-infrared regions for glasses
of composition 80TeO2-10Na2O-10ZnO mol. %, performed on samples of varying
thickness viz. 2.98, 0.50 and 0.20 mm. Due to the high extinction coefficients of
fundamental absorption bands, thin samples were used to make these more
distinguishable.
2000
1750
1500
1250
1000
750
500
250
0
Loss / dB.m -1