Optical fiber link time-frequency distribution device based on femtosecond laser and stabilizing method thereof

Abstract

The invention discloses an optical fiber link time-frequency distribution device based on femtosecond laser. The optical fiber link time-frequency distribution device comprises a main clock transmitter, an isolator, a half-wave plate, a polarization beam splitter, two quarter-wave plates, a reflecting mirror integrated with a stepping motor, a piezoelectric ceramic fiber stretcher, an optical fiber link, an Er<3+> doped optical fiber amplifier, a Faraday polariscope and a clock error detection unit composed of a balance optical cross-correlation system, a PI controller, a data acquisition card and a computer. Two beams of optical pulse signals received by the clock error detection unit are locked within a specific error range by adjusting parameters of the PI controller. The optical fiber link time-frequency distribution device adopts an erbium-doped fiber femtosecond laser locked to a hydrogen maser clock and based on nonlinear polarization evolution (NPE) as the main clock transmitter, utilizes the matching between the piezoelectric ceramic fiber stretcher and the stepping motor to compensate clock errors, achieves femtosecond-level clock synchronization errors in a kilometer-level optical fiber link and ensures long-time stability of the optical fiber link.

Description

technical field [0001] The invention relates to a fiber link stabilization system based on femtosecond laser. Background technique [0002] Large scientific installations play an increasingly important role in promoting basic scientific exploration, biomedicine, and national economic development. Due to its characteristics of large construction scale, complex structure, and comprehensive technology, it puts forward strict requirements for the collaborative control between various functional components. For example, X-ray free-electron laser (XFEL), as the fourth-generation light source, can generate femtosecond X-ray pulses with high repetition rate, high coherence, and ultra-high brightness, and its brightness is nine orders of magnitude higher than that of the third-generation synchrotron radiation light source. A new commanding height in the research of scientific installations at Shanghai University. The XFEL is based on a linear accelerator structure, with a length ra...

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Problems solved by technology

[0003] At present, the clock synchronization achieved by various domestic time-frequency distribution methods is generally on the order of picoseconds (ps), and it is difficult to meet the requirements of the above-mentioned large scientific devices for clock synchronization accuracy. Research must achieve

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