This page contains a Flash digital edition of a book.
COMMUNICATIONS


‘Twisted’ light – a new path for wireless communications


Electronics Testing 2018


electronicstesting@concordepublishing.com Editorial


Direct Line +44 (0) 20 7863 3078 Editor Andy Pye MA (Cantab)


andy.pye@concordepublishing.com


Technical Editor Jonathan Newell BSc jon.newell@concordepublishing.com


Advertising Direct Line +44 (0) 20 7863 3077


Advertising Manager John Harvey john.harvey@concordepublishing.com


Managing Director Paul Williams


paul.williams@concordepublishing.com Concorde Publishing Ltd


100 Borough High Street, London SE1 1LB, UK Main office +44 (0) 20 7863 3079 info@concordepublishing.com


www.EnvironmentalEngineering.org.uk Electronics Testing 2018 is produced by


Concorde Publishing Ltd in association with the Society of Environmental Engineers


important step towards using ‘twisted’ light as a form of wireless, high-capacity data transmission which could make fibre-optics obsolete. Scientists can ‘twist’ photons – individual particles of light – by passing them through a special type of hologram, similar to that on a credit card, giving the photons a twist known as optical angular momentum. While conventional digital communications use photons as ones and zeroes to carry information, the number of intertwined twists in the photons allows them to carry additional data – something akin to adding letters alongside the ones and zeroes. The ability of twisted photons to carry additional information means that optical angular momentum has the potential to create much higher- bandwidth communications technology. “In an age where our global


A


data consumption is growing at an exponential rate, there is mounting pressure to discover new methods of information carrying that can keep up with the huge uptake in data across the world,” says Dr Martin Lavery, head of the Structured Photonics Research Group at University of Glasgow.


20 /// Electronics Testing 2018


team of scientists


based in the UK, Germany, New Zealand and Canada have taken an


While optical angular momentum techniques have already been used to transmit data across cables, transmitting


twisted light across open spaces has been significantly more challenging for scientists to date. Even simple changes in atmospheric pressures across open spaces can scatter light beams and cause the spin information to be lost. Conducting field tests in a real urban


environment in Erlangen, Germany, has revealed exciting new challenges that must be overcome before systems can be made commercially available. Previous studies had indicated the potential feasibility of OAM communication systems, but had not fully characterised the effects of turbulent air on the phase of the structured light propagating over links of this length. The turbulent atmosphere used in


this experiment highlighted the fragility of shaped phase fronts, particularly for those that would be integral to high-bandwidth data transfers. This study indicated the challenges future adaptive optical systems will be required to resolve. “However, with these new developments, we are confident that we can now re-think our approaches to channel modelling and the requirement it places on adaptive optics systems. We are getting ever closer to developing OAM communications that can be deployed in a real urban setting,” added Lavery. EE


The Society of Environmental Engineers 22 Greencoat Place, London SW1P 1PR membership@environmental.org.uk www.environmental.org.uk


The Society of Environmental Engineers (SEE) is a


professional Society that exists to promote awareness of the discipline of environmental engineering, and


to provide members of the Society with information, training and representation within this field.


For information about the Society or to become a member please contact us at


membership@environmental.org.uk


Next in this series...


© Concorde Publishing Ltd 2018 This publication is copyright under the Berne Convention and the international Copyright


Convention. Apart from any fair dealing for the purpose of private study, research, criticism or review, as permitted under the Copyright, Designs and Patents Act, 1988, no part may be reproduced, stored in a retrieval system, or transmitted in any form or by any means,


electronic, electrical, chemical mechanical, photocopying, recording or otherwise, without the prior permission of the copyright owners. Unlicensed multiple copying of the contents of this publication is illegal. Inquiries should be addressed to: The Publisher, Concorde Publishing Ltd, 100 Borough High Street, London SE1 1LB, UK.


Views expressed are those of the authors and are not necessarily endorsed by the Society


of Environmental Engineers or its publishers Concorde Publishing Ltd. Data and conclusions developed are for information only and are not intended for use without independent substantiating investigation by the potential user.


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24