GVD-insensitive stable radio frequency phase dissemination for arbitrary-access loop link.

Area of Science:

• Optical Communications
• Radio Frequency Engineering
• Metrology

Background:

• Disseminating stable radio frequency (RF) signals over long-haul optical fiber links is crucial for various applications, including synchronization and distributed sensing.
• Traditional methods often suffer from phase noise and timing jitter introduced by factors like group velocity dispersion (GVD) and environmental fluctuations.
• Existing schemes lack scalability and robustness for serving multiple users across extensive fiber networks.

Purpose of the Study:

• To propose and demonstrate a novel, stable RF phase dissemination scheme for long-haul optical fiber loop links.
• To eliminate timing jitter caused by GVD by utilizing a single optical source for bidirectional transmission.
• To ensure scalability for arbitrary-access nodes requiring stabilized RF signals.

Main Methods:

• Implementation of a frequency mixing technique for RF phase dissemination.
• Utilizing a single optical source for simultaneous transmission in both directions of a fiber optic loop.
• Experimental setup involving a 100 km fiber-optic loop link and a 2.4 GHz RF signal.

Main Results:

• Successful steady distribution of a 2.4 GHz RF signal to arbitrary points along the 100 km fiber-optic loop.
• Significant reduction in phase jitter at accessing nodes, from 1.87 radians to a maximum of 0.027 radians (RMS) over 1800 seconds.
• Demonstration of the scheme's stability and effectiveness in mitigating timing jitter.

Conclusions:

• The proposed frequency mixing-based RF phase dissemination scheme provides a stable and scalable solution for long-haul optical fiber links.
• The method effectively eliminates timing jitter associated with GVD, ensuring high-precision RF signal delivery.
• The system meets the stringent phase stability requirements for multiple users in diverse applications.