PhoxTroT: Optical Interconnect Technologies Revolutionized Data Centers and HPC Systems

To ensure a constant availability of the Internet applications of service providers like Google, Apple, Facebook or Amazon in all areas independently if they are intended for end users or companies of all sizes, data centers of gigantic dimensions are needed. The energy consumption of such data centers is, of course, exorbitant – and precisely at this point, the now successfully completed EU project “PhoxTroT” saw enormous potential for cost reduction and efficiency.

During a period of 56 months, under the coordination of the Fraunhofer Institute for Reliability and Microintegration, IZM, a consortium with 23 project partners focused on this topic: 50% less energy consumption with a doubling of the data communication rate to two terabits per second was the main goal.

This was achieved by the implementation of optical interconnections at all hierarchy levels: On-Board, Board-to-Board, Rack-to-Rack data links. The overall research and development budget of the project was about 13 Million € with 8.7 Million € EU contribution, which allowed an effort of more than 1050 person-months for the duration of the project.

In May 2017 the project was successfully finalized, bringing breakthrough developments of the PhoxTroT consortium as a whole. The main achievements include the development of data storage systems and subsystems supporting full optical interconnect migration down to end nodes (SEA) for linearly scalable, power and cost reduced data centres, the implementation of a Silicon Photonics process flow in the 200mm fabrication site of ams (AMS), the establishment of multilayer, multimode electro-optical circuit board global platform for high volume fabrication (MAIL) and the establishment of a fabrication pilot line for single-mode electro-optical circuit boards (Fraunhofer IZM) to couple seamlessly to singlemode fibre infrastructures deployed in future exascale data centres and to support integrated silicon photonics applications, the advanced optical design and simulation packages and data centre design architectures and protocols (PHX, AUTH, ICCS, CTI), PIC and hybrid design flow optimization (BP, Fraunhofer IZM), the long wavelength VCSEL and photodiode arrays and their driving/receiving electronics deployment to address emerging singlemode parallel optical transceiver markets (VTL, Fraunhofer HHI, IMEC), the advanced active optical cable development (TE, MLNX, KIT, AMO), 3D silicon photonics switches, transceivers and their advanced 3D assembly (DAS, Fraunhofer IZM, UPVLC, AMO, AUTH) and a full suite of electro-optical circuit board multimode and singlemode waveguide couplers and board-to-board connectors (SEA, Fraunhofer IZM, CEOS and MAIL), the development of flexible, low-loss “Plasmonic Arcs”(CNRS-UB, SDU, Fraunhofer IZM), the development of first hybrid InP-on-SOI nano laser diode (CNRS-LPN).

PhoxTroT brought strong influence on international standards relevant to its core technology areas of chip level interconnect (photonic integrated circuits), board level interconnect (optical circuit boards) and rack level interconnect (AOCs) as well as data centre and HPC architectures. As well as participating in and contributing to a wide range of standardisation committees spanning the PhoxTroT technology fields, PhoxTroT has successfully supported efforts to found a Photonic Integrated Circuit (PIC) working group within the IEC and generated a standardisation roadmap on PIC technologies, “IEC 63072-1 – Photonic Integrated Circuits –

Part 1: Introduction and roadmap for standardization”, which was published by the IEC in May 2017. Furthermore it has created and validated a measurement methodology for optical circuit boards, and created a corresponding international standard, IEC 62496-2/Ed1: General guidance for definition of measurement conditions for optical characteristics of optical circuit boards”, which was published by the IEC in May 2017.

A proactive Intellectual Property Rights management strategy has been successfully deployed resulting in PhoxTroT foreground innovations being captured in 16 patent filings so far, 7 of which have already been granted.Regarding the dissemination of PhoxTroT foreground knowledge to the scientific community, during the lifetime of the project have been generated more than 100 publications to peer-reviewed journals and more than 100 “other dissemination actions” that include invited talks to prestigious conferences in photonics, workshop presentations etc. Moreover PhoxTroT has organized 5 successful Symposia in Optical Interconnects as well as 2 Summer Schools with more than 150 attendees to each event.

In order to exploit the project main results and technologies a new follow up initiative is now available to small and medium-sized enterprises for further development: “PhoxLab” for deep characterization of system embedded photonic interconnect and validation in data centre environment developed into an ‘European Digital Innovation Hub’ at the Fraunhofer IZM in Berlin.

Following up on “PhoxTroT”, the results and applications of further national and European research projects will be provided to start-ups and SMEs – for example, to carry out tests for the certification of their prototypes and developments. Fraunhofer IZM as operator and initiator sees itself as an independent platform for application areas in the field of photonics and data centers of all kinds – and thus lays the foundations for the future of the infrastructure of modern Internet applications.

PhoxTroT consortium partners:
• Fraunhofer Institute for Reliability and Microintegration, Germany (Fraunhofer IZM)
• Fraunhofer Institute for Telecommunications Heinrich-Hertz-Institut, Germany
(Fraunhofer HHI)
• Vertilas GmbH, Germany (VTL)
• Seagate Systems UK Limited, United Kingdom (SEA)
• ams AG, Austria (AMS)
• Meadville Aspocomp International Limited, Hong Kong (MAIL)
• Gesellschaft für Angewandte Mikro und Optoelektronik mit beschränkter Haftung
mbH, Germany (AMO)
• National Technical University of Athens, Institute of Communication and Computer
Systems, Greece (ICCS)
• DAS Photonics SL, Spain (DAS)
• Phoenix BV, Netherlands (PHX)
• The Centre for Research & Technology Hellas, Greece (CERTH/ITI)
• Compas Electro-Optical Systems, Israel (CEOS)
• Bright Photonics BV, Netherlands (BP)
• Computer Technology Institute and Press – “Diophantus”, Greece (CTI)
• Centre National de la Recherche Scientifique Laboratoire Interdisciplinaire Carnot de
Bourgogne, France (CNRS-UB)
• Centre National de la Recherche Scientifique Laboratoire de photonique et de
nanostructures, France (CNRS-LPN)
• Karlsruhe Institute of Technology, Germany (KIT)
• Syddansk Universitet, Denmark (SDU)
• Universitat Politecnica de Valencia, Spain (UPVLC)
• Interuniversitair Micro-Elektronica Centrum vzw, Belgium (IMEC)
• TE Connectivity Nederland BV, Netherlands (TE)
• Aristotelio Panepistimio Thessalonikis, Greece (AUTH)
• Mellanox Technologies LTD, Israel (MLNX)

This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 318240.

http://www.phoxtrot.eu More information about the project goals and highlights can be found on its website