Temperature and strain measurement is an important requirement in many industrial
processes. In areas where high electromagnetic fields, flammable environments or
other adverse environments limit the use of electronic-based sensors, optical fibrebased
sensors can be incorporated.

In this thesis, praseodymium (Pr3)-doped silica optical fibres were investigated for
their temperature and strain properties using the fluorescence lifetime technique.
These fibres had a Pr3+-ion concentration of 700 ppm and lOOOppm, the latter of which was co-doped with Al+3 at a concentration of 4000 ppm.
The Pr3+ ion were excited with light from an argon-ion laser, centred at a wavelength
of 488 nm. Two fluorescence wavelengths that emanated from the 1D2 energy level
were detected and measured, as the doped optical fibre was subject to temperatures
between 20 and 700 °C, or was strained over a range from 0 to 1957 µε.
Results from these measurements indicate that the temperature and strain sensitivity
from these two fibres is comparable to that of other rare-earth-doped silica optical
fibres. The fluorescence lifetime strain-dependence from the optical fibre with a Pr3+ concentration of 1000 ppm had a negative trend with increasing strain; this is contrary
to other rare-earth-doped silica fibre strain sensitivities.