EPSRC logo

Details of Grant 

EPSRC Reference: GR/H01557/01
Principal Investigator: Jackson, Professor D
Other Investigators:
Researcher Co-Investigators:
Project Partners:
Pre Nexus Migration
Department: Sch of Physical Sciences
Organisation: University of Kent
Scheme: LINK
Starts: 01 April 1992 Ends: 30 April 1995 Value (£): 129,256
EPSRC Research Topic Classifications:
EPSRC Industrial Sector Classifications:
Related Grants:
Panel History:  
Summary on Grant Application Form
To undertake research to determine the optimum fibre optic based multiplexing topology and associated signal processing to enable high performance fibre optic based sensors to operate at medium (under 1 km) and long (several km) range in difficult environments without either generating ambiguous data or compromising the performance of any individual sensor.To devise new methods for the interrogation of Bragg grating sensors and identify possible application areas 1.Progress:Two networks of reflective interferometric sensors were evaluated in detail;i) a frequency division matrix network andii) a modified version of this network which included Time Division Multiplexing to increase the number of sensors in the network.This research was conducted at 800 nm to satisfy the medium range requirements of GEC Avionics. These results were one of the deliverables for the LINK partners.In performing this research, Rayleigh back scattering in optical fibres was identified as a factor limiting the performance of reflective interferometric sensors. This was studied both theoretically and experimentally to further characterise its impact on the network.Prior to the collapse of the programme considerable effort had been devoted to source evaluation for multiplexed networks, based on low coherence interferometry and signal processing methods.An electronic equivalent of a white light interferometer was developed for testing signal processing ideas.After discussions with GMMT, studies of various aspects of Bragg Grating Sensors (BGS) for distributed measurements and pollution monitoring were initiated.A new method of discriminating between temperature and strain effects using a single BGS has been introduced. The simultaneous interrogation of a conventional two-beam interferometric sensor and BGS was demonstrated for the first time, using the concepts of low coherence interferometry. We believe this to be a significant advance in the technology of fibre optic sensors as it is now feasible to simultaneously interrogate a large number of point sensors and BGS, which could be installed, for example, in an aircraft. A new method for the interrogation of large arrays of BGS is presently undergoing experimental investigations in our laboratory.Preliminary research was undertaken for the use of spectroscopic techniques, coupled to optical fibres and laser diode sources, for detecting pollutants in ground water. It was recognised that some expensive bulk optic components could be replaced with in-fibre Bragg gratings - a proof-of-principal experiment was performed. We have also proposed a new type of spectrometer based on Bragg gratings 2.Four journal & four conference papers have been published as a result of this research.1 Due to the sale of Seismograph Services to Schlumberger, GEC Avionics, the project leaders, were unable to continue with this LINK project. The project was then uncled by GEC Marconi Materials and Technology (GMMT) resulting in a significant change in the research direction. 2 A small research contract on the feasibility of pollution monitoring using optical techniques was awarded by Shell Oil.
Key Findings
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
Potential use in non-academic contexts
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
Description This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
Date Materialised
Sectors submitted by the Researcher
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
Project URL:  
Further Information:  
Organisation Website: http://www.kent.ac.uk