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Julian Fells

Dr

Julian Fells C Eng

EPSRC Research Fellow / Lecturer at Trinity College

Biography

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.

Trinity College

Most Recent Publications

Single-mode sapphire fiber Bragg grating

Wang M, Salter PS, Payne FP, Shipley A, Morris SM et al. (2022), Optics Express, 30(9), 15482-15482

Altmetric score is

Single-mode sapphire fiber Bragg grating

Fells J, Wang M, Salter P, Payne F, Shipley A et al. (2022), Optics Express

Altmetric score is

A compact full 2π flexoelectro-optic liquid crystal phase modulator

Wang X, Fells J, Shi Y, Ali T, Welch C et al. (2020), Advanced Materials Technologies, 5(12)

Altmetric score is

Millisecond optical phase modulation using multipass configurations with liquid-crystal devices

Jin Y, Elston S, Fells J, Booth M, Welch C et al. (2020), Physical Review Applied, 14(2)

Altmetric score is

Transmissive flexoelectro-optic liquid crystal optical phase modulator with 2π modulation

Wang X, Fells J, Ali T, Lin J-D, Welch C et al. (2020), AIP Advances, 10(5)

Altmetric score is
View all

Research Interests

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.

Current Projects

  • 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.

Most Recent Publications

Single-mode sapphire fiber Bragg grating

Wang M, Salter PS, Payne FP, Shipley A, Morris SM et al. (2022), Optics Express, 30(9), 15482-15482

Altmetric score is

Single-mode sapphire fiber Bragg grating

Fells J, Wang M, Salter P, Payne F, Shipley A et al. (2022), Optics Express

Altmetric score is

A compact full 2π flexoelectro-optic liquid crystal phase modulator

Wang X, Fells J, Shi Y, Ali T, Welch C et al. (2020), Advanced Materials Technologies, 5(12)

Altmetric score is

Millisecond optical phase modulation using multipass configurations with liquid-crystal devices

Jin Y, Elston S, Fells J, Booth M, Welch C et al. (2020), Physical Review Applied, 14(2)

Altmetric score is

Transmissive flexoelectro-optic liquid crystal optical phase modulator with 2π modulation

Wang X, Fells J, Ali T, Lin J-D, Welch C et al. (2020), AIP Advances, 10(5)

Altmetric score is
View all

Publications

Most Recent Publications

Single-mode sapphire fiber Bragg grating

Wang M, Salter PS, Payne FP, Shipley A, Morris SM et al. (2022), Optics Express, 30(9), 15482-15482

Altmetric score is

Single-mode sapphire fiber Bragg grating

Fells J, Wang M, Salter P, Payne F, Shipley A et al. (2022), Optics Express

Altmetric score is

A compact full 2π flexoelectro-optic liquid crystal phase modulator

Wang X, Fells J, Shi Y, Ali T, Welch C et al. (2020), Advanced Materials Technologies, 5(12)

Altmetric score is

Millisecond optical phase modulation using multipass configurations with liquid-crystal devices

Jin Y, Elston S, Fells J, Booth M, Welch C et al. (2020), Physical Review Applied, 14(2)

Altmetric score is

Transmissive flexoelectro-optic liquid crystal optical phase modulator with 2π modulation

Wang X, Fells J, Ali T, Lin J-D, Welch C et al. (2020), AIP Advances, 10(5)

Altmetric score is
View all

DPhil Opportunities

Please get in contact for DPhil opportunities.

Most Recent Publications

Single-mode sapphire fiber Bragg grating

Wang M, Salter PS, Payne FP, Shipley A, Morris SM et al. (2022), Optics Express, 30(9), 15482-15482

Altmetric score is

Single-mode sapphire fiber Bragg grating

Fells J, Wang M, Salter P, Payne F, Shipley A et al. (2022), Optics Express

Altmetric score is

A compact full 2π flexoelectro-optic liquid crystal phase modulator

Wang X, Fells J, Shi Y, Ali T, Welch C et al. (2020), Advanced Materials Technologies, 5(12)

Altmetric score is

Millisecond optical phase modulation using multipass configurations with liquid-crystal devices

Jin Y, Elston S, Fells J, Booth M, Welch C et al. (2020), Physical Review Applied, 14(2)

Altmetric score is

Transmissive flexoelectro-optic liquid crystal optical phase modulator with 2π modulation

Wang X, Fells J, Ali T, Lin J-D, Welch C et al. (2020), AIP Advances, 10(5)

Altmetric score is
View all