All-optical regeneration to unlock capacity of information systems
Considering the plethora of broadband solutions today, connectivity has become more prominent in our lives. New technologies aiming to increase reach and transport capacity are continuously being introduced to meet the rapidly growing demand for finding new swathes of bandwidth and reducing the bit cost. The ARTISTE (Advanced regenerator technologies for high capacity systems) project focused on developing disruptive all-optical signal regeneration approaches by enabling transmission of highly spectral-efficient signals. Researchers' activities ranged across the whole spectrum of future regenerative system development: from device fabrication to network application. The main experimental achievement was development of the first multichannel regenerator with phase-sensitive amplification (PSA) for dual quadrature signals. Comprising a novel carrier extraction and phase synchronisation scheme, the regenerator was implemented using highly non-linear fibre devices that had been fabricated by a project partner. Another experimental activity was implementation of the first all-optical add-drop multiplexer for orthogonal frequency-division multiplexing signals. In addition to experimental work, researchers also conducted important theoretical work on regenerative system design. Firstly, they investigated transmission performance of non-linear regenerative channels based on cascaded PSAs with focus on the impact of phase and amplitude noise mechanisms. Then, they worked on developing an analytical technique to define optimum conditions and operating margins of cascaded PSA-based regenerators in multilevel phase-encoded transmission links. Rigorous numerical simulations demonstrated that all-optical regeneration significantly boosts system performance when using complex signals, but reduces operating margins. Based on this, the team successfully designed novel regenerator configurations for advanced modulation formats that significantly suppressed noise. In future transmission systems, the channels will be densely packed and tight filtering will be required. Traditional solutions have overlooked retiming for future high-capacity systems. Researchers developed a new regeneration scheme for highly spectral-efficient formats based on the three Rs of signal regeneration: reamplifying, reshaping and retiming. Project results were disseminated through conferences and 31 publications in high-impact journals.
Keywords
All-optical, signal regeneration, bandwidth, ARTISTE, all-optical add-drop multiplexer
