The Distributed Optical Fibre Sensors Research Group, led by Dr Trevor Newson investigates novel distributed optical fibre sensors and laser designs for sensing applications. With over 25 publications and 3 patents in the last two years it is a leading player in the technological development of Distributed Optical Fibre Sensors.
Distributed Fibre Optic sensors offer unique possibilities for monitoring a wide range of variables. Their distinctive property is the ability to spatially resolve the measurand along the entire length of the sensing fibre. Two of the most important areas of interest are distributed temperature and strain measurements. The University of Southampton has enjoyed a very successful collaboration with York Sensors Ltd, a local Southampton company that leads the world in distributed temperature sensing. Although the various specifications can be tailored to a precise application typical specifications that they have achieved are 1C temperature resolution and 1 metre spatial resolution over a range of 10km. Typical applications include monitoring chemical processes in unfriendly environments such as pressure vessels, brick lined reactors ovens and driers, maximising efficiency in electrical power transmission fire detection particularly in underground or concealed locations, and general management of oil, liquid gas and chemical flows.
Present research is now directed towards two main objectives. The first objective is to increase the range of distributed temperature sensors to above 50km. The second objective is to develop a distributed strain sensor. Strain sensing is particularly useful for monitoring large engineering structures e.g. bridges, dams, roads etc. Another important application is the monitoring of strain in existing optical fibre communication networks; excessive strain leads to expensive premature failure of the link.
In order to achieve these objectives we are exploring various non-linear scattering phenomena in optical fibre which are sensitive to the measurand of interest. The scattered signals which are processed are inevitably very weak, so both detection and the pump light which generates the scattered signals have to be optimised. Southampton University has unique capabilities for fibre fabrication and also considerable experience in design and manufacture of Erbium doped fibre lasers and amplifiers. Future work will take full advantage of this expertise, leading to the generation of distributed fibre sensors.