Relay method in optical fiber optical frequency link and relay station for implementing the method

Abstract

The invention discloses a relay method in an optical fiber optical frequency link and a relay station for implementing the method. The method comprises the following steps: using the signal of a previous level optical fiber link as seed light to receive and amplify a part of the seed light and send the seed light to the next level optical fiber link; and the other part of the seed light is reflected to return to the previous level link along the original route, a part of return light of the next level optical fiber link is received to serve as beat frequency to inhibit the noise so as to inhibit the import phase noise in an amplification process. By adoption of the relay method disclosed by the invention, the problem of controlling the width of a band in a phase noise inhibition process can be well solved, and the relay method has the advantages of adaptability to complex links, simple structure, low cost, and so on. The relay station of the optical fiber optical frequency link designed in the invention can be applied to optical atom clock comparison, ultra high precision optical clock signal transmission, optical fiber time frequency system networking, gravitational wave detection and other high-tech fields.

Description

technical field [0001] The invention belongs to the technical field of optical fiber communication, and relates to a relay method and a relay station, in particular to a relay method in an optical fiber optical frequency link and a relay station for realizing the method. Background technique [0002] With the rapid development of optical fiber communication technology and the successful development of optical clocks, great changes have taken place in the transmission of high-precision time-frequency signals. At present, the instability and uncertainty of strontium atomic optical clocks have reached 10 -18 / day magnitude. Traditional time-frequency signals are transmitted over long distances in the form of microwaves through satellite links, and the transmission stability can only reach 10 -16 On the order of / day, its transmission accuracy can no longer meet the long-distance transmission of high-precision optical clock signals. Therefore, the technology that can directl...

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Problems solved by technology

However, there are three defects in this scheme: first, because the scheme needs to directly transmit the signal light for 1840km and needs a part of the light to be returned for phase noise suppression, the control bandwidth of the whole system is very narrow, only a dozen Hz; The structure of the Brillouin amplifier is complex and unstable, and it is easy to lose the lock. After the lock is lost, it needs to be re-locked by a special person; third, the optical fiber in this solution is laid along the oil and gas pipeline, and most of them are in the outskirts of the inaccessible suburbs. The noise introduced by the environment very small

However, this relay scheme requires a narrow linewidth laser with good performance in the relay station structure, and it must work in a frequency-locked manner, which greatly increases the complexity and cost of the relay station

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