A remote two-way optical phase comparison method and device based on local measurement

Abstract

The invention discloses a remote bidirectional optical phase comparison method based on local end measurement and a realization device thereof. Two lasers separated at two different places are taken as light sources. The two lasers are connected through a remote optical fiber link. Output light signals of the two lasers are transmitted on the same optical fiber in opposite directions. The signal light of one laser is sent to the local end through the optical fiber link and carries out frequency beat with the other laser. The signal light of the other laser is sent to a remote end, is reflected, is returned back by the same way and carries out frequency beat with the signal light itself. Phases of two frequency beat signals are compared. The common mode phase noise of the optical link is passively eliminated, thereby comparing the two lasers. According to the method and the device, the structure does not refer to active compensation of the link noise, so closed loop control is unnecessary, a lock loss problem does not exist, and the reliability of a comparison loop is relatively high. The method and the device are not influenced by a transmission function of an interferometer, so the method and the device can be used for evaluating the phase noise of broadband signals.

Description

technical field [0001] The invention belongs to the technical field of optical fiber comparison, and relates to a two-way optical phase comparison method, in particular to a remote two-way optical phase comparison method based on local end measurement and an implementation device thereof. Background technique [0002] In recent years, with the continuous development of optical frequency combs, optical fiber communication and other related technologies, the current research results of optical clocks have made great progress, and the frequency stability and uncertainty of optical clocks have exceeded 10. -18 order of magnitude, the traditional long-distance transmission scheme of time-frequency signals using satellite links, because the transmission stability of one day can only reach 10 -16 The order of magnitude cannot meet the requirements of high-precision remote optical clock comparison. With the maturity of optical fiber communication technology, long-distance optical f...

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Problems solved by technology

[0005] 1. The existing technology schemes have high requirements on the time synchronization of the phase measurement process in different places. It is necessary to ensure that the acquisition of the phase or frequency information of the beat frequency signals in the two places has a high degree of simultaneity, and it is not easy to realize the true sense of different places.

[0006] 2. Some components of the circuit required by the existing technology scheme are relatively complex, and it is easy to introduce irrelevant radio frequency noise, which affects the comparison result

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