Free-space quantum key distribution during daylight and at night
Current satellite-based quantum key distribution (QKD) is limited to nighttime operations, and the reliance on microwave communication for key distillation leads to significant delays, often spanning several days. These challenges collectively hinder the establishment of a practical global-scale qua...
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Veröffentlicht in: | Optica 2024-05, Vol.11 (5), p.647 |
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Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | Current satellite-based quantum key distribution (QKD) is limited to
nighttime operations, and the reliance on microwave communication for
key distillation leads to significant delays, often spanning several
days. These challenges collectively hinder the establishment of a
practical global-scale quantum network. Here, by developing a 625-MHz
inherently robust decoy-state light source and daytime noise
suppression close to the Fourier transform limitation, we achieve QKD
covering all the 24 h of the day over a 20-km terrestrial free-space
channel, resulting in an average secure key rate of approximately
495 bps. Additionally, bidirectional laser communication is integrated
into the QKD transmitter and the ground station to enable real-time
key distillation, improving the timeliness from days to real time.
This comprehensive verification lays a solid foundation and paves the
way for all-day real-time QKD with quantum satellites. |
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ISSN: | 2334-2536 2334-2536 |
DOI: | 10.1364/OPTICA.511000 |