Julian Fells
Lecturer in Engineering Science


After a first class degree in Electronic Engineering from University College London and a PhD in Optical Modulators from University of Bath, I spent 20 years in industrial research. Ten of these were in two corporate research centres: GEC-Marconi, Caswell and Nortel Networks, Harlow Laboratories. Following this I held senior positions in two start-up companies. I was Research and Product Development Manager at Splashpower Ltd. leading research into wireless power transfer. Following this I was Optical Systems Manager at Stingray Geophysical Ltd. leading research and development on a large scale optical fibre sensor system for the off-shore oil and gas industry. In 2015 I returned to academia, taking up a research position within the Soft Matter Photonics Group in Engineering Science.


At Trinity I am tutor to first and second year students in Engineering Science, covering Electronic and Information Engineering. I have tutored third year students in Electronic Circuits and Communications for two years. I have also tutored first year students in Electronic and Information Engineering at both Jesus College and Brasenose College. Additionally I supervise fourth year projects in Engineering Science.


My research has encompassed optoelectronic devices, optical fibre devices, optical fibre communications, optical fibre sensors, wireless power, and liquid crystal devices.  This has been for diverse fields, including telecommunications, oil and gas, civil engineering, defence, manufacturing and consumer electronics. Highlights of my research have included inventing the Twin Fibre Grating Tunable Dispersion Compensator and the first Negative Chirp Electro-absorption Modulator. This latter device is now a key component in optical communication networks.

Selected Publications

D.J. Hansford,  J.A.J. Fells,  S.J. Elston, and  S.M. Morris, “Speckle contrast reduction of laser light using a chiral nematic liquid crystal diffuser”, Applied Physics Letters 109, 261104 (2016).

S.M. Wood, J.A.J. Fells, S.J. Elston, and S.M. Morris, “Wavelength Tuning of the Photonic Band Gap of an Achiral Nematic Liquid Crystal Filled into a Chiral Polymer Scaffold”, Macromolecules 29, 8643-8652 (2016).