Optical fiber time transmission technology based on a double-fiber round-trip method

Area of Science:

• Optical Communications
• Precision Timing
• Fiber Optic Sensing

Background:

• Accurate time transmission in optical fiber systems is crucial for high-speed networks.
• Environmental factors like temperature changes cause fluctuations in fiber length and transmission delay.
• Existing methods struggle to mitigate these temperature-induced errors effectively.

Purpose of the Study:

• To develop and validate a new optical fiber time transmission technology using a double-fiber round-trip method.
• To eliminate the impact of ambient temperature variations on one-way transmission delay measurements.
• To improve the precision of time interval error measurements compared to traditional methods.

Main Methods:

• Implementation of a double-fiber round-trip system connecting master and slave stations with varying fiber lengths (100 km and 80 km).
• Direct calculation of one-way transmission delay using three time interval counters and their ratio.
• Testing under a wide temperature range (-20°C to 40°C) to assess performance.

Main Results:

• The double-fiber round-trip method significantly reduces time interval error from 1.4 ns to 80 ps (1310-1550 nm) and 320 ps to 80 ps (1490-1550 nm).
• The proposed method effectively eliminates errors caused by fiber length expansion and round-trip delay fluctuations due to temperature changes.
• Achieved high precision timing over long-distance optical fiber links.

Conclusions:

• The double-fiber round-trip method offers a robust solution for accurate optical fiber time transmission.
• This technology enhances the reliability and precision of timing in optical communication systems, especially under variable environmental conditions.
• The findings demonstrate a substantial improvement in time interval error reduction compared to single-fiber methods.