Polarization control method, based on genetic algorithm, of optical fiber disturbance system and device thereof

Abstract

The invention discloses a polarization control method, based on the genetic algorithm, of a distributed optical fiber disturbance positioning system. In the polarization control process, the genetic algorithm is adopted as a control algorithm, and an extrusion-type polarization controller is adopted to modulate the polarization state of interference optical waves; with the relevancy of two interference signals received by a detector in the distributed optical fiber disturbance positioning system as a feedback signal, the impressed voltage value, corresponding to the maximum relevancy of two interference signals, of the extrusion-type polarization controller is searched for according to the genetic algorithm. A polarization control system comprises a distributed optical fiber disturbance sensing system based on the dual Mach-Zehnder interferometer principle, the extrusion-type polarization controller, a lithium niobate birefringence phase modulator, a single-chip microcomputer system and a computer. According to the polarization control method of the distributed optical fiber disturbance positioning system, the polarization-induced fading resistance of the system can be effectively improved by adjusting the polarization state of interference light, and the influence of birefringence of single-mode optical fibers on the positioning precision of the system can be eliminated to a great extent.

Description

technical field [0001] The invention belongs to the technical field of sensing and detection, in particular to a polarization control system of an optical fiber perturbation system. Background technique [0002] With the development of science and technology and the enhancement of people's security awareness, it has become a necessary and urgent problem to develop a perimeter security system with large detection range, low energy consumption and low cost. Due to its high sensitivity, anti-electromagnetic interference, and no power supply, the distributed optical fiber vibration sensing system has been widely used in military defense, financial protection, energy security, community security and other security fields, and will have a wide range of applications in the future. application prospects. [0003] One of the necessary conditions for light waves to interfere is that the light vectors participating in the interference have the same vibration direction, that is, they h...

AI Technical Summary

Problems solved by technology

The fiber used in the actual disturbance system is a common single-mode fiber. Due to the birefringence characteristics of the single-mode fiber, the polarization state of the light wave will change after entering the fiber, resulting in the degradation of the polarization state of the linearly polarized light.

In the field of sensing, this will reduce the visibility of interference fringes, or even disappear, so that the system's positioning accuracy for disturbances will be greatly reduced

[0004] Although the polarization-maintaining fiber can keep the polarization state of the light unchanged, since the optical fiber laying distance of the distributed fiber-optic vibration sensing system is generally tens of kilometers, the use of polarization-maintaining fiber will make the system cost too high

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