Optimization of a Polarization-Encoding System for Practical Quantum Key Distribution

  • Hugo F. Costa University of Aveiro / University of Coimbra
  • Nelson J. Muga University of Aveiro
  • Nuno A. Silva University of Aveiro
  • Armando N. Pinto University of Aveiro


We present a method for optimizing the waveplate’s voltage range of an electro-optic based electrical polarization controller for qubit encoding in discrete-variable quantum key distribution (QKD). By increasing the number of used waveplates, the maximum voltage range to generate each of the states-of-polarization required by a QKD protocol can be reduced. The proposed machine learning algorithm, particle swarm optimization, was validated through numerical and experimental results. Results show that transitions between six states of polarization used in QKD systems can be generated using a maximum voltage range of 10V in each waveplate.


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COSTA, Hugo F.; MUGA, Nelson J.; SILVA, Nuno A.; PINTO, Armando N.. Optimization of a Polarization-Encoding System for Practical Quantum Key Distribution. In: WORKSHOP DE COMUNICAÇÃO E COMPUTAÇÃO QUÂNTICA (WQUANTUM), 2. , 2022, Fortaleza. Anais [...]. Porto Alegre: Sociedade Brasileira de Computação, 2022 . p. 43-51. DOI: https://doi.org/10.5753/wquantum.2022.223949.