Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Optics Express

Femtosecond-level timing fluctuation suppression in atmospheric frequency transfer with passive phase conjunction correction

Fuyu Sun, Dong Hou, Danian Zhang, Jie Tian, Jianguo Hu, Xianhe Huang, Shijun Chen

Published Aug 23, 2017• 27 citations
Publisher

Abstract

at 1000 s. This atmospheric comb-based frequency transfer with passive phase conjunction correction can be used to build an atomic clock-based free-space frequency transmission link because its instability is less than that of a commercial Cs or H-master clock.
DOI
10.1364/oe.25.021312

Related papers

Femtosecond atmospheric frequency transfer using diode laser with electronic phase compensation

Shijun Chen, Dawei Chen, Qiang Chen +4 more

We demonstrated an atmospheric radio-frequency transfer over a 50 m outdoor free-space link using a compact diode laser with an electronic phase compensation technique. With transferring a 1 GHz microwave signal in 5000 seconds, the total root-mean-square (RMS) timing fluctuation was measured to be about 560 fs, with fractional frequency instability on the order of 4 × 10-13at 1 s, and order of 4 × 10-16at 1000 s. This atmospheric frequency transfer scheme can be used to disseminate a commercial Rb or Cs clock via a free-space transmission link.

Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS)•Jul 1, 2017•0 citations

Point-to-point stabilized optical frequency transfer with active optics

Benjamin P. Dix-Matthews, Sascha Schediwy, David R. Gozzard +8 more

Abstract Timescale comparison between optical atomic clocks over ground-to-space and terrestrial free-space laser links will have enormous benefits for fundamental and applied sciences. However, atmospheric turbulence creates phase noise and beam wander that degrade the measurement precision. Here we report on phase-stabilized optical frequency transfer over a 265 m horizontal point-to-point free-space link between optical terminals with active tip-tilt mirrors to suppress beam wander, in a compact, human-portable set-up. A phase-stabilized 715 m underground optical fiber link between the two terminals is used to measure the performance of the free-space link. The active optical terminals enable continuous, cycle-slip free, coherent transmission over periods longer than an hour. In this work, we achieve residual instabilities of 2.7 × 10 −6 rad 2 Hz −1 at 1 Hz in phase, and 1.6 × 10 −19 at 40 s of integration in fractional frequency; this performance surpasses the best optical atomic clocks, ensuring clock-limited frequency comparison over turbulent free-space links.

arXiv:2007.04985•Nature Communications•Jan 22, 2021•75 citations

Frequency comb-to-comb synchronization between a 1.3-km free-space link via an optical frequency transfer

Jaewon Yang, Dong Il Lee, Dong-Chel Shin +3 more

Optical frequency comb technology has been revolutionizing optical fields of ultra-precision metrology over two decades, connecting the SI unit standards of various optical clocks with utmost accuracy and stability. With an increasing demand for free-space communication and time/frequency transfer applications, the frequency comb is stretching its versatility even the outside of laboratory. Still, the environmental disturbances of free space degrade the excellent phase noise of the optical frequencies, hindering the reliable utilization of frequency comb at any desirable location. This research performs comb-to-comb synchronization over a 1.3-km Free-Space Optical link (FSO) with frequency stability of 3.80×10-15 at 0.1 s averaging time throughout the entire comb spectrum. Phase-locked loop compensates the Doppler shift of optical frequencies propagating atmospheric free-space channel, providing optical references for synchronizing distant frequency comb.

Free-space laser communication technologies. Conference•Mar 12, 2024•0 citations

Long-haul Transfer of Optical Frequencies in Free Space

Hyun Jay Kang, Jaewon Yang, Young‐Jin Kim +1 more

We report experimental results of concurrent transfer of multiple optical frequencies, coherently generated from an optical frequency comb, over an 18 km free-space link with real-time compensation of atmospheric phase noise.

Conference on Lasers and Electro-Optics•Jan 1, 2019•0 citations

Analog transmission of time-frequency signal in atmospheric turbulence environment

Zhenfeng Guo, Zehui Lu, Sensen Meng +5 more

The high-precision time-frequency transfer of the optical atomic clock signals over ground-to-satellite and terrestrial free-space laser paths is of great significance in the fields of fundamental and applied sciences. However, the phase noises caused by atmospheric turbulence severely degrade the measurement precision. In this paper, a new method to simulate the transmission of time-frequency signal propagating through atmospheric turbulence is investigated. An analog transmission system comparable to the practical out-field link has been demonstrated, which can provide a deep insight into the phase distortion of time-frequency signal of free-space optical communication links.

Optics Express•Aug 23, 2022•5 citations

Portable Atmospheric Frequency Transfer over Outdoor Free-space Link with Compact Diode Laser

Jie Tian, Zhengyu Ji, Dong Hou

We demonstrated a portable atmospheric radio-frequency transfer over a 120 m outdoor free-space link using a compact diode laser as the clock carrier. Timing fluctuation and Allan Deviation are both measured to characterize the instability of transferred frequency incurred during the transfer process. In this experimental setup, all components were powered by a full-charged battery, and the experiment was conducted in an open-air environment, which is far from the laboratory-based room. With transferring a 100 MHz microwave signal in 4500 seconds, the total root-mean-square (RMS) timing fluctuation was measured to be about 22 ps, with fractional frequency instability on the order of 3 × 10-12at 1 s, and order of 4 × 10-14at 1000 s. We found that the majority of this excess timing fluctuation in our experiment is attributed to the air turbulence which could contribute a jitter at tens picosecond level in a normal windy night. This portable atmospheric frequency transfer scheme can be used to fast build an atomic clock-based frequency free-space transmission link since its stability is superior to a commercial Rb or Cs clock.

IEEE International Conference on Communication Technology (ICCT)•Oct 28, 2020•0 citations
We demonstrated an atmospheric radio-frequency transfer over a 50 m outdoor free-space link using a compact diode laser with an electronic phase compensation technique. With transferring a 1 GHz microwave signal in 5000 seconds, the total root-mean-square (RMS) timing fluctuation was measured to be about 560 fs, with fractional frequency instability on the order of 4 × 10-13at 1 s, and order of 4 × 10-16at 1000 s. This atmospheric frequency transfer scheme can be used to disseminate a commercial Rb or Cs clock via a free-space transmission link.
Abstract Timescale comparison between optical atomic clocks over ground-to-space and terrestrial free-space laser links will have enormous benefits for fundamental and applied sciences. However, atmospheric turbulence creates phase noise and beam wander that degrade the measurement precision. Here we report on phase-stabilized optical frequency transfer over a 265 m horizontal point-to-point free-space link between optical terminals with active tip-tilt mirrors to suppress beam wander, in a compact, human-portable set-up. A phase-stabilized 715 m underground optical fiber link between the two terminals is used to measure the performance of the free-space link. The active optical terminals enable continuous, cycle-slip free, coherent transmission over periods longer than an hour. In this work, we achieve residual instabilities of 2.7 × 10 −6 rad 2 Hz −1 at 1 Hz in phase, and 1.6 × 10 −19 at 40 s of integration in fractional frequency; this performance surpasses the best optical atomic clocks, ensuring clock-limited frequency comparison over turbulent free-space links.
Optical frequency comb technology has been revolutionizing optical fields of ultra-precision metrology over two decades, connecting the SI unit standards of various optical clocks with utmost accuracy and stability. With an increasing demand for free-space communication and time/frequency transfer applications, the frequency comb is stretching its versatility even the outside of laboratory. Still, the environmental disturbances of free space degrade the excellent phase noise of the optical frequencies, hindering the reliable utilization of frequency comb at any desirable location. This research performs comb-to-comb synchronization over a 1.3-km Free-Space Optical link (FSO) with frequency stability of 3.80×10-15 at 0.1 s averaging time throughout the entire comb spectrum. Phase-locked loop compensates the Doppler shift of optical frequencies propagating atmospheric free-space channel, providing optical references for synchronizing distant frequency comb.
The high-precision time-frequency transfer of the optical atomic clock signals over ground-to-satellite and terrestrial free-space laser paths is of great significance in the fields of fundamental and applied sciences. However, the phase noises caused by atmospheric turbulence severely degrade the measurement precision. In this paper, a new method to simulate the transmission of time-frequency signal propagating through atmospheric turbulence is investigated. An analog transmission system comparable to the practical out-field link has been demonstrated, which can provide a deep insight into the phase distortion of time-frequency signal of free-space optical communication links.
We demonstrated a portable atmospheric radio-frequency transfer over a 120 m outdoor free-space link using a compact diode laser as the clock carrier. Timing fluctuation and Allan Deviation are both measured to characterize the instability of transferred frequency incurred during the transfer process. In this experimental setup, all components were powered by a full-charged battery, and the experiment was conducted in an open-air environment, which is far from the laboratory-based room. With transferring a 100 MHz microwave signal in 4500 seconds, the total root-mean-square (RMS) timing fluctuation was measured to be about 22 ps, with fractional frequency instability on the order of 3 × 10-12at 1 s, and order of 4 × 10-14at 1000 s. We found that the majority of this excess timing fluctuation in our experiment is attributed to the air turbulence which could contribute a jitter at tens picosecond level in a normal windy night. This portable atmospheric frequency transfer scheme can be used to fast build an atomic clock-based frequency free-space transmission link since its stability is superior to a commercial Rb or Cs clock.