The increasing demand for bandwidth in optical fibre communication systems has prompted a significant research effort into developing efficient fibre based optical amplifiers at operating wavelengths neighbouring the erbium-doped fibre amplifier. Of the possible candidates, thulium-doped fibre amplifiers appear best suited to serve this need with amplification available from 1460 to 1530 nm. However, the current limitation with these devices is that the amplifying transition can only provide sufficient gain when doped into host materials with relatively low phonon energies. The ultimate goal for thulium-doped amplifiers is to incorporate the ion into a host material which can be easily integrated into standard communication systems without compromising gain; this thereby involves, to some degree, a silica based host material. To date, optical amplification in the telecommunication S-band using thulium-doped silica fibres has been inefficient due to the high phonon energy associated with Si-O bonds in the glass. This work undertakes a systematic study on the effects of network modifiers on the S-band amplifying transition in an effort to improve the radiative quantum efficiency in silica based glasses. To this end, the techniques employed in this investigation included modifying the glass network with elements which may act to reduce the local phonon energy surrounding the thulium (Tm3+) ion and co-doping the Tm3+ ions with sensitising ytterbium (Yb3+) ions.
| Identifer | oai:union.ndltd.org:ADTP/256791 |
| Date | January 2008 |
| Creators | Simpson, David Allan |
| Source Sets | Australiasian Digital Theses Program |
| Detected Language | English |
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