Quantum-limited optical time transfer for future geosynchronous links
arXiv:2212.12541 · doi:10.1038/s41586-023-06032-5
Abstract
The combination of optical time transfer and optical clocks opens up the possibility of large-scale free-space networks that connect both ground-based optical clocks and future space-based optical clocks. Such networks promise better tests of general relativity, dark matter searches, and gravitational wave detection. The ability to connect optical clocks to a distant satellite could enable space-based very long baseline interferometry (VLBI), advanced satellite navigation, clock-based geodesy, and thousand-fold improvements in intercontinental time dissemination. Thus far, only optical clocks have pushed towards quantum-limited performance. In contrast, optical time transfer has not operated at the analogous quantum limit set by the number of received photons. Here, we demonstrate time transfer with near quantum-limited acquisition and timing at 10,000 times lower received power than previous approaches. Over 300 km between mountaintops in Hawaii with launched powers as low as 40 W, distant timescales are synchronized to 320 attoseconds. This nearly quantum-limited operation is critical for long-distance free-space links where photons are few and amplification costly -- at 4.0 mW transmit power, this approach can support 102 dB link loss, more than sufficient for future time transfer to geosynchronous orbits.
References in corpus (18)
- Hunting for topological dark matter with atomic clocks
- A clock network for geodesy and fundamental science
- Gravitational wave detection with optical lattice atomic clocks
- Optical two-way time and frequency transfer over free space
- On orbit performance of the GRACE Follow-On Laser Ranging Interferometer
- Atomic Clocks for Geodesy
- Quantum Tests of the Einstein Equivalence Principle with the STE-QUEST Space Mission
- Synchronization of Distant Optical Clocks at the Femtosecond Level
- 113 km Free-Space Time-Frequency Dissemination at the 19th Decimal Instability
- Carrier-phase Two-Way Satellite Frequency Transfer over a Very Long Baseline
- A coherent optical link through the turbulent atmosphere
- Femtosecond Synchronization of Optical Clocks Off of a Flying Quadcopter
- Free-space transfer of comb-rooted optical frequencies over an 18 km open-air link
- Comparing optical oscillators across the air to milliradians in phase and in frequency
- Ultra-stable Free-Space Laser Links for a Global Network of Optical Atomic Clocks
- Free-space optical links for space communication networks
- The unit of time: present and future directions
- Measurement of the impact of turbulence anisoplanatism on precision free-space optical time transfer
Cited by in corpus (15)
- Roadmap towards the redefinition of the second
- Squeezed dual-comb spectroscopy
- Versatile Optical Frequency Division with Kerr-induced Synchronization at Tunable Microcomb Synthetic Dispersive Waves
- Dual-comb-enhanced microwave clock synchronization over commercial fiber
- Nanometric dual-comb ranging using photon-level microcavity solitons
- Time-Frequency Transfer over Optical Fiber
- Classical and Quantum Frequency Combs for Satellite-based Clock Synchronization
- Free Space Optical Frequency Comparison Over Rapidly Moving Links
- On-Chip Parametric Synchronization of a Dissipative Kerr Soliton Microcomb
- Node-downloadable frequency transfer system based on a mode-locked laser with over 100 km of fiber
- Rhythmic soliton interactions for integrated dual-microcomb spectroscopy
- Quantum synchronization and entanglement of dissipative qubits coupled to a resonator
- Free space optical link to a tethered balloon for frequency transfer
- A plug-and-play solution for characterizing two-way optical frequency transfer over free-space
- Enhanced timing of a 113 km O-TWTFT link with digital maximum likelihood estimation process