Seminar: Optically controlled microwave and millimetre switches

28 October 2020, 10.00 AM - 28 October 2020, 11.00 AM

Prof Martin Cryan


Speaker: Prof Martin Cryan

Talk Title: Optically controlled microwave and millimetre switches


Reconfigurable (or tunable) microwave and millimetrewave circuits have a huge number of applications from military and commercial radar systems to smart antennas for mobile phones. This presentation shows a radically new way of implementing tunability using light interaction with semiconductors. If light is absorbed by a semiconductor like silicon, electron-hole pairs are generated. If sufficient numbers of electrons are generated they form a “plasma” which acts like a metal at microwave and millimetrewave frequencies. These Optically Induced Plasmas can be used as a technology platform to create fast, linear, high power microwave and milliemtrewave control circuits. This talk will present recent results and future directions for this work.


Professor Cryan has worked in the fields of electromagnetic modelling, device and circuit fabrication for 34 years. He worked for GEC Marconi Instruments from 1986-1988  and then for Quasar Microwave from 1988-1990.

He did a PhD at Bath University in GaAs MMIC design from 1991-1994. He did a post-doc at the University of Birmingham from 1994-1997 working for Prof. Peter Hall on Active Integrated Antennas. He then moved to Italy to work for Prof. Roberto Sorrentino at the University of Perugia from 1997-1999  working on Integrated Antennas and sub-millimetrewave devices. He became a lecturer at Bristol in 2002 and a Professor of Applied Electromagnetics and Photonics in 2012.

He has been working on optically controlled microwave devices since 2013, initially sponsored by L3-TRL. He is Co-I on a newly awarded EPSRC grant (GLIMMER) developing Phononic Integrated Circuits for RF applications which use integrated acoustic waveguides in GaN to implement ultra-small RF filtering and delay devices. He has recently worked on GaN semiconductor photonics devices as part of a major EPRSC grant on nanoscale manufacturing ( of which he is the Bristol PI.

He is Co-I and Co-Director of a major EPSRC project QuPIC which aims to develop the world’s first integrated quantum photonics foundry service. He was PI on an EPSRC grant on GaN Photonic Crystal fluorescence sensors and PI on an EPSRC grant to develop Integrated Tunable Flat Lenses. He is also Scientific Advisor to a new University start-up which is developing low cost fluorescence based biosensors. He has published 106 Journal (1 Science Front Cover, 2008), 15 Invited and >150 International conference papers.

Contact information

Please contact Harriet Parks, Smart Internet Lab Project Coordinator - for more information about this talk.

Prof Martin Cryan

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