Stable radio frequency dissemination by simple hybrid frequency modulation scheme

Area of Science:

• Physics
• Optical Engineering
• Signal Processing

Background:

• Accurate radio frequency (RF) signal transfer over long distances is essential for modern communication and scientific applications.
• Existing methods often face challenges with phase noise and environmental disturbances in optical fiber transmission.
• Developing robust and high-precision RF transfer systems remains a key research area.

Purpose of the Study:

• To propose and demonstrate a novel fiber-based stable radio frequency transfer system.
• To achieve high fractional frequency instability over extended optical fiber links.
• To utilize a hybrid frequency modulation scheme for enhanced signal stability.

Main Methods:

• A hybrid frequency modulation scheme combining two RF signals onto a single laser diode.
• Utilizing one frequency component for phase fluctuation detection and another for derivative compensation.
• Maintaining a specific frequency ratio (parameter m) to prevent signal interference.
• Experimental transfer of a 200 MHz RF signal over 100 km of optical fiber using a 1 GHz reference signal.

Main Results:

• Successful transfer of a stable 200 MHz radio frequency signal over a 100 km optical fiber link.
• Achieved a fractional instability of 2×10⁻¹⁷ at an averaging time of 10⁵ seconds.
• Demonstrated the effectiveness of the hybrid frequency modulation scheme in mitigating phase fluctuations.

Conclusions:

• The proposed fiber-based system offers a highly stable method for radio frequency transfer.
• The hybrid frequency modulation technique is effective in achieving state-of-the-art frequency instability.
• This technology has significant implications for metrology, communication networks, and fundamental physics experiments.