Open AccessInvestigation of underwater quantum channels in a 30 meter flume tank using structured photons
Author(s) -
Felix Hufnagel,
Alicia Sit,
Frédéric Bouchard,
Yingwen Zhang,
Duncan England,
Khabat Heshami,
Benjamin J. Sussman,
Ebrahim Karimi
Publication year - 2020
Publication title -
new journal of physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.584
H-Index - 190
ISSN - 1367-2630
DOI - 10.1088/1367-2630/abb688
Subject(s) - physics , underwater , quantum key distribution , quantum information science , quantum channel , photon , quantum cryptography , polarization (electrochemistry) , underwater acoustic communication , optics , quantum , superposition principle , quantum mechanics , quantum information , quantum entanglement , oceanography , chemistry , geology
Underwater quantum communication has recently been explored using polarization and orbital angular momentum (OAM). Here, we show that spatially structured modes, e.g., a coherent superposition of beams carrying both polarization and OAM, can also be used for underwater quantum cryptography. We also use the polarization degree of freedom to investigate the impact of the channel length on key rates for quantum communication applications. The underwater channel proves to be a difficult environment for establishing quantum communication as underwater optical turbulence results in significant beam wandering and distortions. However, the errors associated to the turbulence do not result in error rates above the threshold for establishing a positive key in a quantum communication link with both the polarization and spatially structured photons. The impact of the underwater channel on the spatially structured modes is also investigated at different distances using polarization tomography.