Tellurite And Fluorotellurite Glasses For Active And Passive

8. Fibre drawing; MDO 368
A small number of studies have been performed on oxide tellurite fibres [18, 29-32],
but none to the authors knowledge on fluoride containing tellurite fibres. Wallenberger et
al. [32] reported transmission between 50 and 70 % (1.5 to 3.0 dB.m -1 by this authors
calculations, however this would depend of the method used to obtain transmission in this
study) in the 500 nm to 2.5 µm region for TeO2-Al2O3 fibre. Wang et al. [18] reported
losses of 1.0 to 1.5 dB.km -1 for the 1 to 1.6 µm region for TeO2-ZnO-Na2O fibre, but
losses increased significantly beyond this band. Kim et al. [30] reported transmission of
around 75 % in the 500 to 700 nm region for TeO2-Na2O-Li2O glass fibre doped with
LiNbO3. Burger et al. [29] reported optical loss for bulk TeO2-ZnO-PbO-PbF2-Nb2O5-
La2O3 glasses of around 0.2 dB.m -1 at 6800 cm -1 (1.47 µm), but this increased
significantly into the visible and infrared regions. Fluorotellurite fibre was pulled in the
Burger et al. [29] study, but was too lossy to measure the attenuation. Shen et al. [31]
reported loss of around 0.5 dB.m -1 at around 1.3 µm for TeO2-Na2O-ZnO glass fibre, but
this loss increased exponentially to lower and higher wavelengths (see section 2.5.1.1.).
Therefore, the fibre pulled in this study is the lowest loss fluorotellurite fibre to date (5
dB.m -1 ) over a wide wavelength range (700 nm to 2.5 µm). Fig. (8.21) shows the
fluorotellurite fibre pulled in this study (MOF005) guiding light.