High Capacity Space Division Multiplexing Systems

Our information society relies to an unprecedented extent on broadband communication solutions such as high-speed Internet access, mobile voice and data services, multimedia broadcast systems, etc. To fulfil the steadily growing volume and bandwidth demand of those data services while simultaneously reducing the cost per transported information bit, communication systems have been continuously improved in terms of reach and aggregate transport capacity. However, it is now recognised that communication systems are rapidly approaching the fundamental information capacity of current technology, a trend with potential negative impact on the economy and social progress.

HSPACE project targeted the development of advanced spatial-division-multiplexed (SDM) systems to unlock the capacity of future information systems by enabling the transmission of spatial super-channels over a single fibre. The proposed concept was implemented mainly using and few-mode fibres (FMFs) as underlying technology platform along with novel digital signal processing (DSP) techniques that minimise the mode interference and inter mode nonlinearities, keeping the required digital processing at realizable levels.

The other main objective of the project included multidisciplinary scientific training in optical communications, photonic device technologies, advanced modelling methods and DSP techniques enabling Dr. Filipe Ferreira to become a research leader in this challenging area of enormous practical relevance. Additionally, the project allowed the development of the Fellow soft-skills such as foreground intellectual property (IP) protection, communication skills, management skills ensuring that he is equipped to be a future leader in industry, or academia. On the other hand, the AIPT benefited from the Fellow strong theoretical background on modelling and design of FMFs as well as on the simulation of SDM transmission.

Dr. Ferreira received during the project training from Prof. Andrew Ellis, and other colleagues at Aston addressing various topics, such as: project management, IP, technical writing, open access and research data management, as well as career and personal development planning. He successfully completed Introduction to Learning and Teaching Practises (ILTP) course and Postgraduate Certificate in Learning &Teaching in Higher Education (PGCert).
The Fellow’s training needs were addressed through a personal Career Development Plan aimed at diversifying and complementing his research skills and knowledge, providing him with a range of special technical training in the area of optical communications and DSP techniques.

During HSPACE, the Fellow has extensively developed his communication, teamwork, networking and initiative skills as described in the following:

Communication
• Authored 19 peer-reviewed publications, 9 of which as 1st author, including IEEE and OSA high-impact journals.
• Widely participated in international leading conferences in the field, 13 conference papers (7 presented) 4 of which were invited.
• Member of the AIPT board which activities include but are not restricted to strategic planning, financial broad picture, decisions on internal proposals, and evaluating performance.
• Delivered 3 outreach actions including one summer school (“Building a 3dB Noise Figure Erbium-Doped Fibre Amplifier” through the Nuffield Research Placements programme).
• Successfully applied to the ERC Starting Grant 2017.
• More than doubled the number of citations during HSPACE reaching 438 citations with H-factor 10 and I-factor 10, according to Google Scholar database.

Teamwork
• Main responsible for the setup of a bespoke computing cluster for optical communication systems simulations.
• Delivered more than 20 hours of lectures and tutorials in optical communications and mathematics.
• Co-supervised the work of 1 PhD student managed by Profs Ellis.
• Collaborated with multiple PIs on the development of consortia and proposals in the area of optical signal processing.

Networking
• Strong personal network with colleagues from academia and industry.
• Influenced the formation of research proposals in terms of the development of scientific ideas, consortium building, proposal preparation (including conflict management) and final preparation.
• Participated in international collaborative projects (INSPACE and PEACE). Maintained individual collaborations on 30% of the papers published since joining Aston.

Initiative
• Leading inventor on one patent regarding spatial-division multiplexing and optical capacity enhancement: “Twin-Fibres for Communication beyond the Kerr Nonlinearity Limit”.
• Leading the creation of a start-up on optical capacity enhancement through the Research and Enterprise Office at Aston University.

Dr. Ferreira major achievements during HSPACE were in the area of Nonlinear Compensation Methods, Nonlinear Capacity of Few-Mode Fibre Links, Designing of Few-Mode Fibre Links and Spatial-Mode-Shift-Keying, as I detail below:

Nonlinear Compensation Methods
A) Pioneered a novel in-line nonlinear compensation (NLC) method based on all-optical optical coherent superposition that takes no additional bandwidth of the network elements (fully backward compatibility), and limits PMD accumulation to one span (~80km). This method can deliver multiple 3dB SNR boosts by exploiting the network’s dark-fibre. A novel double-stage interferometer enables the coherent superposition. Dr. Ferreira is the lead inventor on the twin-fibres GB patent application (no. 1605120.3).
B) Extended the digital back-propagation (DBP) method to mode-multiplexed systems. A DBP implementation based on Manakov equations provides significant gain for a linear mode coupling around -50dB/100m and differential mode delay smaller than 100ps/km, which can be achieved with existing fibres.

Nonlinear Capacity of Few-Mode Fibre Links
C) First to estimate the coupling strength required for the suppression of nonlinear distortion in few-mode fibres below that of an isolated mode propagating without intermodal nonlinear distortion or intermodal coupling. A linear mode coupling above -20dB/100m is required, which is possible in practice following the appropriate fibre design rules.

Designing of Few-Mode Fibre Links
D) First to identify the analytical relation between the group delay spread in FMFs with the real-world fibres operating in the intermediate regime, this is operating neither in the weak nor the strong coupling regime. The knowledge of group delay spread is critical to dimension the receiver memory and transmission reach, and to estimate the nonlinear limited capacity.

Spatial-Mode-Shift-Keying
E) Development of a proof-of-concept experiment to generate spatial-mode-shift-keying signals using one single highly-efficient all-dielectric metasurface that has the unique ability of simultaneous converting different input polarizations of an incoming LP01 signal into different orthogonal LP modes. The patent includes an experimental demonstration of a conventional polarization multiplexed (or shift-keyed) signal being converted into a mode multiplexed (or shift-keyed) signal (LP21 and LP11) and back into polarization multiplexed signal, a 100G DP-QPSK transponder was used.

Periodic Reporting for period 1 - HSPACE (High Capacity Space Division Multiplexing Systems)

Diese Seite teilen

Herunterladen