The 4th IEEE International Conference on Telecommunications and Photonics (ICTP) 2021

December 22-24, 2021, Dhaka, Bangladesh

Keynote Speech  

Quantum Communication and Post-quantum Cryptography – Physical Layer Security with Multimode Fibers using Densely Connected Convolutional Network



Prof. Juergen Czarske
Professor, Faculty of Electrical and Computer Engineering

Laboratory of Measurement and Sensor Systems, Competence Center for Biomedical Computational Laser Systems (BIOLAS) and Institute for Applied Physics

TU Dresden, Germany



Single mode fiber optic networks enabled the emergence of the modern internet. Multimode fibers (MMF) not only offer the potential to significantly increase data rates by utilizing the spatial domain. The MIMO (Multiple-Input and Multiple-Output) approach enables improvements in the secrecy rate, post-quantum cryptography strategies and novel quantum communication strategies. In contrast to mathematically difficult problems such as prime factorization, the physical properties of MIMO fiber systems with speckle patterns as fingerprint can be exploited, whereby a quantum computer would have no advantage. However, the high distortion of the MMF initially reduces the information, but it is precisely this property that can be used to encrypt the transmitted data and finally to correct the distortion (*). In addition to using of spatial light modulators and modern real-time holography for mode decomposition of MMF, we have implemented deep learning techniques. Densely connected convolutional network enable real-time mode decomposition with a latency below 10 ms. The achieved paradigm shift with adaptive computational laser metrology for MMF networks will be reported.

* S. Rothe, N. Koukourakis, H. Radner, A. Lonnstrom, E. Jorswieck, and J. W. Czarske, “Physical layer security in multimode fiber optical networks”, Scientific reports, vol. 10, no. 1, pp. 1–11, 2020.

Stefan Rothe, Qian Zhang, Nektarios Koukourakis and Jürgen W. Czarske, "Intensity-only Mode Decomposition on Multimode Fibers using a Densely Connected Convolutional Network,"  IEEE/OSA Journal of Lightwave Technology.




Juergen Czarske (Fellow OSA, SPIE, EOS, Senior Member IEEE) is professor, director and senator of TU Dresden, Germany. He studied electrical engineering and physics and obtained PhD degree and the Venia Legendi (promotion for professor). His awards include the 1996 AHMT Measurement Technique Prize, the 2008 Berthold Leibinger Innovation Prize for Laser Technique, the 2019 OSA Joseph Fraunhofer Award/Robert M. Burley Prize, and the 2020 Laser Instrumentation Award of IEEE Photonics Society. Prof. Czarske has conducted more than 800 talks and papers, especially over 200 papers in peer-reviewed journals, over 100 invited talks and he holds over 30 patents. Prof. Czarske is associate editor of Journal of the European Optical Society (EOS) - Rapid Publications, elected member of Saxon Academy of Science, the Scientific Society for Laser Technology (WLT), board member of German Society of Applied Optics (DGaO), advisor of Student Chapter Dresden of SPIE and he is the general chair of the world congress for optics and photonics ICO-25-OWLS-16-Germany-Dresden-2022.