Researchers from Chalmers University of Technology, Sweden, and Tallinn University of Technology, Estonia, have demonstrated a 4,000km fibre-optical transmission link using ultra low-noise, phase-sensitive optical amplifiers. The reach improvement shown is 5.6 times that which is possible when using conventional erbium-doped fibre amplifiers.
Professor Peter Andrekson, who leads optical communication research at Chalmers University of Technology said that the demonstration shows how amplifiers can ‘significantly, and simultaneously’ reduce the impact of noise accumulation – originating from optical amplifiers in the link – and of signal distortion from nonlinear effects in the transmission fibre.
Professor Peter Andrekson leads the optical communication research at Chalmers University of Technology (credit Henrik Sandsjö)
New technologies such as those demonstrated will be increasingly required to meet the demand for higher transmission capacity created by video streaming, cloud storage and other online services, as Andrekson explained: ‘While there remain several engineering challenges before these results can be implemented commercially, the results show, for the first time, in a very clear way, the great benefits of using these amplifiers in optical communication.’
‘Such amplifiers may also find applications in quantum informatics and related fields,’ he continued, ‘where generation and processing of quantum states are of interest, as well as in spectroscopy or any other application which could benefit from ultra-low-noise amplification.’
The research was funded by the European Research Council (ERC), the Swedish Research Council, and the Wallenberg Foundation.
Recovered signal constellation diagrams comparing conventional amplification and phase-sensitive amplification in an amplifier noise limited regime (-2 dBm launch power) and a fibre nonlinearity limited regime (8 dBm launch power). (Credit: Samuel Olsson)
Read the paper: Samuel L.I. Olsson, Henrik Eliasson, Egon Astra, Magnus Karlsson, Peter A. Andrekson. Long-haul optical transmission link using low-noise phase-sensitive amplifiers. Nature Communications, 2018; 9 (1) DOI: 10.1038/s41467-018-04956-5