While ever higher resolution temperature sensing is of demand in research and
industry, the cost of sensors in the sub-milli-Kelvin (mK) range can be restrictive.
Furthermore, as the majority of commercial temperature sensor measurements are
transmitted via electrical circuits, significant post-processing is required to obtain a
high-resolution due to phenomena such as electromagnetic interference, selfheating,
electrical noise, etc. Consequentially, research in recent years has focused
on the development of several technologies which overcome this issue, with optical
fibre sensors proving to be a viable option. Owing to this, the following chapter will
aim to review the current state-of-the-art in liquid filled optical fibre temperature
sensing and the underlying methods.