Quantum Limits of Optical Communication II

19-21 September 2018, Warsaw, Poland


Ever growing demand for the capacity of optical communication systems calls for better understanding of their ultimate limits and more efficient strategies to utilise available resources. At the fundamental level, optical systems are described by quantum mechanics, which adopts a different view on the task of information transmission compared to the classical theory of electromagnetic waves: in the quantum mechanical description, data are carried in general by non-orthogonal quantum states rather than well defined macroscopic quantities such as the amplitude or the phase. This approach enables reduction of error rates below the shot noise level and provides more general bounds on the capacity of optical channels.

The motivation of this workshop is to bring together the communities interested in the fields of optical communication and quantum information science. The objective is to learn from each other about recent major developments in our respective fields, our current scientific theoretical and experimental challenges, and most important open questions ahead. This interaction could potentially open new interdisciplinary lines of research, re-focus some existing lines of research, or exchange of theoretical tools or technological know-how.

Quantum information tools can be used to provide fundamental limitations to currently existing optical communication technology. For example, one can investigate fundamental limitations to the recovery of the signal over non-linear channels or the communication capacity of deep-space communication links under energy constraints. These recent results could be of interest to the optical communication community and feedback on them would be extremely valuable to the quantum information scientists.

On the other hand, it would be interesting for theoreticians working in quantum information theory to have a deeper understanding of the model of non-linear optical channels used by the community of optical communication in order to be able generalize the recent quantum bound on the communication capacity of optical linear channels to non-linear channels. The classical version of this problem remains open and only upper and lower bounds are currently know. We hope that the interaction between both communities will help to make progress in studies of the capacities of non-linear channels in both communities.

Main topics include:

  • Capacity limits of optical channels
  • Nonlinear effects in optical signal propagation
  • Noise in optical communication links
  • Mode multiplexing and demultiplexing techniques
  • Sub-shot noise receivers
  • Quantum-limited optical signal discrimination


  • Konrad Banaszek (University of Warsaw)
  • Raúl García-Patrón (Universite Libre de Bruxelles)
  • Marcin Jarzyna (University of Warsaw) - secretary
  • Christoph Marquardt (Max Planck Institute for the Science of Light)