Tellurite And Fluorotellurite Glasses For Active And Passive

8. Fibre drawing; MDO 353
Table (8.6): Optical loss of unstructured fibre of composition MOF005 - 70TeO2-
10Na2O-20ZnF2 (mol. %), with increasing melting time [9].
Loss / dB.m -1
Melting
time 4000 cm
/ hr.
-1
6452 cm
2.5 µm
-1
7634 cm
1.55 µm
-1
10000 cm
1.31 µm
-1
14000 cm
1 µm
-1
714 nm
3 38.25 5.02 4.64 7.52 20.55
4 13.22 2.14 2.25 3.92 9.46
5 2.89 3.63 5.46 8.58 14.90
10 3.82 4.21 4.68 5.25 4.71
This shows a general decrease in loss with melting time. The OH absorption band at 2.5
µm was removed with fluorination, and scattering significantly reduced in the 10 hour
melt.
8.3. Discussion
8.3.1. Stress in a proposed core / clad pair
Different thermal expansion coefficients are inevitable in a core / clad pair, therefore,
stresses will be generated in the resulting fibre. Table (8.7) summarises some thermal and
mechanical properties for a possible core / clad optical fibre pair [9].