Compensator and compensation method for transmission delay in optical fiber time frequency transmission

Abstract

The invention discloses a compensator and compensation method for transmission delay in optical fiber time frequency transmission. The compensator comprises a central station and a remote terminal, wherein the central station is connected with the remote terminal through optical fibers, the central station comprises a time frequency scale source, a frequency multiplier I, a frequency multiplier II, a filter I, a frequency mixer I, a frequency mixer II, a filter II, a light emitting module I, a combiner, a light receiving module I and an amplifier I, and the remote terminal comprises a wave separator, an optical modulator I, an optical modulator II, a light receiving module II, an amplifier II, a filter III, a phase shifter, a power divider, a light emitting module II and an electrical interface. The compensation method includes the steps that the central station conducts long-distance injection locking on a photoelectric oscillator of the remote terminal, the remote terminal accumulates errors and transmits the errors back to the central station, the central station conducts compensation through phase delay and a fluctuation regulation and control circuit, and therefore the output of the photoelectric oscillator of the remote terminal is locked to the central station. According to the compensator and the compensation method, the asymmetry of two-way delay is eliminated, therefore, the transmission accuracy can not be limited by the measurement accuracy of the system, and accurate long-distance transmission can be conducted.

Description

technical field [0001] The invention relates to the technical field of transmission time delay compensation in optical fiber transmission, in particular to a compensator and method for transmission time delay in optical fiber time-frequency transmission. Background technique [0002] Time frequency is the basic physical quantity of matter existence and the basis of people's daily life, production and scientific research. The transmission of time-frequency reference signals includes the foreign GPS / GLONASS multi-source time synchronization-based space-based time-frequency network and the domestic "Beidou" second-generation satellite positioning and navigation system. In general, the space-based time-frequency system can achieve time synchronization accuracy on the order of nanoseconds and 10 -15 Frequency transfer stability per day. However, when the time and frequency of higher-precision clock sources (such as ion clocks, fountain clocks, and optical clocks) need to be tra...

AI Technical Summary

Problems solved by technology

The well-connected optical cable network provides a mature physical path for time-frequency signal transmission. The optical network built on the physical network can be used as a reference time synchronization network, but its original design purpose is to serve communication services, so its accuracy Affected by the network greatly, the time synchronization accuracy can only reach the order of hundreds of nanoseconds

But its disadvantage is that the assumption of round-trip and return delays is not easy to meet due to the existence of fiber dispersion when the same link uses different wavelengths, the error of compensation Δθ at the sending end is large, and the two-way time delay is asymmetrical, which makes the transmission accuracy of time-frequency signal optical fiber transmission low, and The output of the photoelectric oscillator at the remote station cannot be synchronized with the central station, and long-distance transmission cannot be realized

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