Julian Fells C Eng

Dr Julian Fells received a First Class degree in Electronic Engineering from University College London in 1991 and a PhD in Optical Modulators from the University of Bath in 1995, He then spent twenty years in industrial research. Ten of these were in two corporate research centres: GEC-Marconi, Caswell and Nortel Networks, Harlow Laboratories. Following this, he held senior positions in two start-up companies. He was Research and Product Development Manager at Splashpower Ltd. pioneering research into wireless power transfer. Following this he was Optical Systems Manager at Stingray Geophysical Ltd. leading the research and development of a large-scale optical fibre sensor system for the off-shore oil and gas industry.

In 2015 Dr Fells joined the Department of Engineering Science. In 2020 he was awarded a 5-year EPSRC Research Fellowship. He has been a lecturer at Trinity College since 2017. Highlights of Dr Fells’ research include: devising the negative chirp electroabsorption modulator (standardised as 10GBASE-ZR), inventing the twin fibre grating tunable dispersion compensator and inventing the ultralow standby-power system found in Qi Wireless Chargers.

Dr Fells leads a research area in optical fibre sensors with the support of a £1.2M Fellowship grant from the Engineering and Physical Sciences Research Council. The research uses a femtosecond laser to inscribe novel structures into optical fibres to sense parameters such as temperature, pressure and strain. The optical fibres are typically around 0.1 mm in diameter and can have many sensors along their length for quasi-distributed sensing. These sensors allow measurements to be made remotely in extreme environments, such as those with high temperature and pressure.

In order to access ultra-high temperature environments, sapphire optical fibre is used. The sensors can be used to instrument infrastructure such as aero engines and fusion reactors. The data collected can then be used to optimise these systems to be more efficient and less polluting.

• Sapphire optical fibre sensors for ultra-high temperatures
• Optical fibre
• Bragg gratings for strain and temperature measurement
• Optical fiber pressure sensors
• Hollow core fibre gas specroscopy
• Multiscale multidimensional imaging for laser processing
• Multimode fibre microscopy
• Liquid crystal optical phase modulators.

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