High precision active fiber optic microwave frequency transmission system

Abstract

Provided is a high-precision active optical fiber microwave frequency transmission system, comprising a local end, an optical fiber link, and a far end. The local end and the far end are connected through the optical fiber link. The local end sends a forward signal. The far end receives the forward signal and returns the signal to the local end. The local end processes a to-be-transmitted frequency signal and a backward signal, and drives the sent forward signal to be conjugate with phase jitter introduced by a single-direction optical fiber link. The forward signal received by the far end is a stable microwave frequency signal. Through a method of frequency conversion, influence of back scattering noise is prevented, signal to noise ratio is improved, being beneficial for improving short stability of frequency transmission. Forward and backward transmission share the same fiber and wave, wavelength asymmetry caused by using wavelength division multiplexing is eliminated, and influence of wavelength interval on frequency transmission long-term stability is prevented.

Description

technical field [0001] The invention relates to the technical field of optical fiber time-frequency transmission, in particular to a high-precision active optical fiber microwave frequency transmission system. Background technique [0002] As a basic physical quantity, time frequency has been widely used in deep space scientific research, determination of basic physical constants and standard distribution of high-precision clocks. In recent years, various countries (especially developed countries) have invested heavily in related high-tech to support their development. With the application of new technologies, the indicators of existing frequency standards have been continuously improved, and their performance has been improved by an order of magnitude in about 7 to 10 years. At present, the best microwave clock reference source is an atomic clock based on cesium, and its long-term frequency instability is within 10 -16 order of magnitude. The principle of high-stability a...

AI Technical Summary

Problems solved by technology

However, the transmission of different wavelength optical carriers will cause the asymmetry of the forward and backward transmission delays, which will affect the long-term stability of the frequency signal when the transmission distance increases or the temperature changes greatly.

[0005] A simple way is to use different wavelengths of light to transmit to different user ends, but this requires multi-channel optical signals on the one hand, and on the other hand will cause the asymmetry of the transmission delay mentioned above

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