Author Affiliations
1CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China2Information and Navigation College, Air Force Engineering University, Xi’an 710077, Chinashow less
Fig. 1. Hierarchical quantum network operating in different atmospheric layers. LEO, low Earth orbit; MEO, medium Earth orbit; GEO, geostationary Earth orbit; HAP platform, high-altitude platform; UAV, unmanned aerial vehicle.
Fig. 2. Recent progress in airborne quantum communications. In clockwise order, the first downlink QKD demonstration in 2013 using the hot-air balloon by Wang
et al.[46], the basis detection and compensation experiment in 2014 using the Z-9 helicopter by Zhang
et al. from the Chinese Academy of Sciences
[50], the first uplink QKD demonstration in 2017 using the Twin Otter research aircraft by Pugh
et al. from the University of Waterloo
[45], the first drone-based entanglement distribution in 2020 using UAV by Liu
et al. from the Nanjing University
[48,49], the drone-based QKD test in 2017 using DJI S1000+ octocopter by Hill
et al. from the University of Illinois
[5153" target="_self" style="display: inline;">–53], the free-space QKD in 2015 based on a moving pick-up truck by Bourgoin
et al. from the University of Waterloo
[54], and the first air-to-ground QKD demonstration in 2013 using the Dornier-228 aircraft by Nauerth
et al. from the Ludwig-Maximilians University
[44].
Fig. 3. Block diagrams of airborne QKD system. QRNG, quantum random number generator; Mod, modulator; Aux, auxiliary devices; TDC, time-to-digital converter; ATP, acquisition, tracking, and pointing; FSM, fast-steering mirror; PSD, position-sensitive detector; C, coupler; M, mirror; SPD, single-photon detector.
Fig. 4. Link configurations for airborne QKD.
Fig. 5. Secure key rates with different PER.
Fig. 6. Quantum source and transmitter in the ground-to-air QKD demonstration
[45].
Fig. 7. ATP system in the drone-based entanglement distribution experiment
[48].
Fig. 8. Schematic diagrams of time synchronization precision.
Initiative | Platform | Distance and Loss | Height | Velocity (km/h) | Results | Wavelength (nm) | System Clock Rate (MHz) | Quantum Signal Detector | Operation Time |
---|
Wang et al., 2013[46] | Hot-air balloon | 20 km | N/A | 0 | Downlink, polarization-coded BB84 268.87 bps (secure key) | 850 | 100 | Si avalanche photodiode (APD)a | Night | | Nauerth et al., 2013[44] | Dornier-228 | 20 km | 1.1 km | 290 | Downlink, polarization-coded BB84 145 bps (sifted key) | 850 | 10 | Si APD | After sunset | 38 dB | Zhang et al., 2014[50] | Z-9 | 2.5–7.5 km | | 100 | Downlink (polarization basis detection and compensation) | 850 | 1 | Si APD | Night | Pugh et al., 2017[45] | Twin Otter | 3–10 km | 1.6 km | 198–259 | Uplink, polarization-coded BB84 263.7–347 bps (secure key) | 785 | 400 | Si APD | Night | 34.4–51.1 dB | Liu et al., 2020[48] | UAV | 200 m 12 dB | | 0 | Downlink polarization entanglement distribution (CHSH-S parameter ) | 810 | N/A | Si APD | Daytime/clear/rainy night | Alexander et al., 2017[51–53] | UAV (DJI S1000+) | | N/A | N/A | Downlink, project: polarization-encoded BB84 | 650 | 100 | Si APD | Indoor/outdoor night | 10–20 dB | Quintana et al., 2019[59] | UAV | 1 km | N/A | N/A | Downlink/uplink, project: BB84 based on photonic integrated circuits (PICs) | 1550 | N/A | Indium gallium arsenide (InGaAs) detector in Geiger modeb | N/A | | Liu et al., 2021[49] | UAV | ∼1 km | | 0 | Relayed entanglement distribution (CHSH-S parameter ) | 810 | N/A | Si APD | Night | 20 dB |
|
Table 1. List of Recent Airborne Quantum Communication Experiments and Related Projects
Representative Examples | Nauerth et al., 2013[44] | Zhang et al., 2014[50] | Liu et al., 2020[48] |
---|
Components | Transmitter | Receiver | Transmitter | Receiver | Transmitter | Receiver |
---|
Coarse pointing | Type | Torque | 2-axis | 2-axis | 2-axis | 3-axis | 3-axis | | | motors | gimbal | gimbal | gimbal | gimbal | gimbal | | Tracking range | | | Azimuth | Azimuth | Azimuth | Azimuth | | | | | Elevation | Elevation | Elevation | Elevation | | | | | | | | | Fine pointing | Type Range | VCM | PM | FSM | FSM | PZT FSM | PZT FSM | Coarse camera | Type | InGaAs | InGaAs | CMOS | CMOS | CMOS | CMOS | | FOV | 48 mrad | 12.8 mrad | 2° () | 1° () | | | Fine camera | Type | 4QD | InGaAs | CMOS | CMOS | PSD | PSD | | FOV | 3.3 mrad | 960 µrad | 512 µrad | 512 µrad | | | | Frame rate | | 400 Hz | 2.3 kHz | 2.3 kHz | 60 kHz | 60 kHz | Beacon laser | Divergence | 3 mrad | | 1 mrad | | 10 mrad | 10 mrad | Tracking error | | 500 µrad | | | | () | () |
|
Table 2. ATP Performance of the Typical Airborne Quantum Communication Experiments