Photonics for greener networks
Technologies to radically improve the energy efficiency of the photonics components that will power tomorrow's internet are the theme of CIP Technologies' stand at ECOC.
Whilst it is recognised that broadband provides a route to save energy from travel substitution, and provide more efficient ways of working, it does not come without some cost to the environment. Telecoms currently consumes about 2% of the power within a developed economy and this will surely grow unless actions are taken. The importance of this issue is now recognised by the requirements that telecoms operators are now placing on their suppliers, and by regulatory bodies.
Fibre communication is more energy efficient than either copper or wireless but as bandwidth demands grow the choice of the photonic technology within the network will have a bearing on overall power consumption. In order to reduce the network CAPEX and OPEX, one crucial aspect is to reduce or even remove the need for temperature control and cooling of photonic components, especially within data centres and at the central office.
CIP is focused on tackling the reduction of power consumption in future networks in two new complementary 7th Framework EU projects: C3PO (Colourless and Coolerless Components for low Power Optical Networks) and BIANCHO (Bismide And Nitride Components for High temperature Operation).
C3PO is an industry led project that brings together world experts in electrical and optical components, optical systems and system providers including ADVA Optical Networking (Germany), Constellex (Greece), CIP and Polatis (UK) as industrial partners and University College Cork/Tyndall National Institute (Ireland) and IMEC (Belgium) as academic partners.
The project will promote the concept of "reflective photonics" as a method to reduce the complexity and power consumption of DWDM network terminal equipment for metro, data-centre and access network applications operating up to 100GbE rates. To this end, CIP will design and develop the integrated photonic components for these novel architectures. Components will be designed to operate "Coolerless" to avoid the current dependence on inefficient thermoelectric coolers. "Colourless" (wavelength agnostic) operation will be also implemented in order to enable easier network provisioning and maintenance and hence to reduce OPEX. Furthermore, the combination of C3PO "reflective photonics" in conjunction with energy-optimised optical switching modules leads to lower cost solutions for fully wavelength reconfigurable IPoDWDM.
Within the project CIP will be using both monolithic integration and its advanced hybrid integration platform HyBoardT to develop a range of green photonic components with reduced footprint and power consumption, including DWDM array lasers, transmitter and receiver arrays and monolithic amplifying modulators. CIP will actively commercialise the optical technology developed in C3PO so it is available for use in the next generation of optical networks.
BIANCHO is a longer term project aimed at new material systems to radically improve the performance of optoelectronic components. The project brings together Philipps Universitaet Marburg (Germany) and Semiconductor Research Institute (Lithuania) focussing on material growth and characterisation, Tyndall National Institute (Ireland), internationally recognised for its strength in semiconductor band structure modelling and the University of Surrey (UK) who contribute unique characterisation facilities and modelling expertise. CIP will focus on design, fabrication and commercialisation of advanced devices using the new materials developed in the project.
The project will develop new semiconductor materials to allow lasers and other photonic components to become more energy efficient and also more tolerant of high operating temperatures.
Many current photonic components for telecommunications applications have major intrinsic losses, with around 80% of the electrical power used by a laser chip being emitted as waste heat, for example. The presence of this waste heat necessitates the use of thermo-electric coolers and an air-conditioned environment in order to control the device temperature, cascading the energy requirements by more than an order of magnitude.
The energy losses are mainly due to a process known as Auger recombination, a consequence of the band structure of the semiconductor materials used in making components such as semiconductor lasers and optical amplifiers. Over many years, incremental approaches have sought to reduce the consequent inefficiencies without addressing their fundamental cause. BIANCHO proposes a radical change of approach: to eliminate Auger recombination by manipulating the electronic band structure of the semiconductor materials through the use of novel dilute bismide and dilute nitride alloys of gallium arsenide and indium phosphide. This will allow the creation of more efficient and temperature tolerant photonic devices which could operate without the power-hungry cooling equipment that today's networks demand.
CIP will be describing in more detail the technology it is developing to underpin more cost effective and greener networks at ECOC 2010 Turin in the invited paper Mo.1.B.1, "Reflective Based Active Semiconductor Components for Next Generation Optical Access Networks" and the market focus session "Mining the Wavelength Domain for Future Fibre Access: Technology and Cost Challenges" (Mass-Market Broadband Fibre Access session).