All-Raman optical amplification for next Generation ultra-wideband Optical Networks (ARGON)

The aim of this proposed research is to address the modelling, design, demonstration and potential applications of ultra-wide-band (UWB) optical fibre amplifiers based on the Raman effect, induced by high power laser pumping of specially designed optical fibre, for future applications in optical fibre communication networks, ranging from inter-data-centre connections to metro/regional networks.

Despite massive advances in the capabilities of optical fibre communication systems over the past two decades, enabled by digital coherent technology, internet traffic growth remains well above 20% per annum, and is forecast to continue on a strong trajectory for the foreseeable future. Delivering a seamless optical amplifier of unprecedented bandwidth is now seen by operators and their network equipment suppliers as the most practical and cost-effective way to increase the traffic carrying capacity of the billions of km of glass fibre that has been deployed worldwide, by making use of the wide low-loss window.

The programme targets two specific designs of all-Raman amplifier: (i) a node-located, discrete-only parallel, dual-stage design, and (ii) a hybrid distributed-discrete dual-stage design, making use of the intra-node transmission fibre as a gain medium for part of the spectrum. These innovative designs are enabled by recent increases in laser pump powers and novel nonlinear Raman gain fibres, and a growing, general acceptance of Raman technology by all network operators, ranging from relatively conservative incumbents, such as Verizon, to more adventurous technology giants, such as google.

New, nonlinear, modelling tools will be developed to overcome and support the significant experimental design challenges in manufacturing and operating our proposed UWB amplifiers, which with 300nm bandwidth offer approaching 10x the bandwidth of standard Erbium-doped fibre amplifiers used in today's networks. Key optical amplifier characteristics such as gain, noise figure, uniformity and nonlinearity will be measured stand-alone. UWB optical fibre communication system capacity improvements and performance will be evaluated in representative models of target networks, informed by our project partners, and compared with extensive in-line and recirculating loop UWB laboratory-based tests.

ARGON will be of benefit to the researchers and leading product development teams in existing UK based photonic industries in the optical communication systems supply chain including, for example, Lumentum, II-VI, Socionext, Xtera, Corning, and Huber-Suhner. Internationally, in the absence of a large UK-based network equipment manufacturer, it will impact upon the leading international companies who have a UK presence, including Ciena, Cisco, Huawei, Infinera, and Nokia.

The programme will be transformative because it will deliver the key enabling photonic sub-system, an ultra-wide-band (UWB) all-Raman optical amplifier, for a long-anticipated paradigm shift from relatively narrowband (40nm) operation limited by the bandwidth of the ubiquitous C-band Erbium-doped fibre amplifier to UWB optical networking, based on a scalable range of solutions, and maturing, manufacturable component technologies. Whatismore, compared with alternative approaches which theoretically offer greater capacity gains such as spatial division multiplexing, this technology path offers the most convincing and cost-effective business case at the network operator level, since it expands nearly ten-fold the usage of the most valuable networking resource, in which the last decade has witnessed massive global investments, namely the under-utilised cables of low loss, intrinsically UWB standard, single-mode fibre already in the ground.

ARGON will follow a full research programme lifecyle, producing output deliverables primarily in the form of leading peer-reviewed journal papers in our specialist field, such as the Journal of Lightwave Technology and Optics Express, and the highest profile international conferences, OFC and ECOC.

In the UK, there exists a large, internationally leading community of university based researchers in optical devices, circuits, and sub-systems, who will be guided and influenced by our results. In Europe, we will leverage our participation in multiple EU Training Networks, particularly Initial Training Network WON, to influence, collaborate with and steer the work of leading universities and industrial R&D teams. We also expect the research interests and product development plans of our internationally leading, multi-national projects partners to be strongly influenced by the results of our work; and as has been our past experience, we expect a wide range of additional industry partners to take interest in our work as it progresses, from start-up component suppliers to network equipment manufacturers.

The specific pathways to impact activities associated with the project have been outlined in the "Pathways to Impacts" attachment.