Design And Implementation Of Optical Polarization Stabilize

Due to the advantages of long transmission distance and strong anti-interference ability,optical fiber communication systems have been widely used in communication networks.With the development and application of polarization multiplexing and coherent detection technology,the channel capacity and transmission distance of optical fiber communication systems have been further improved.At the same time,the influence of the instability of the signal light polarization state on the communication system is becoming more and more obvious.The polarization mode dispersion caused by the random change of the polarization state increases the bit error rate of the optical fiber communication system and limits the system transmission bandwidth.Therefore,real-time and accurate stabilization of the polarization state of the signal light in the system is of great significance for highspeed optical fiber communication systems.This paper studies and designs a polarization stabilization system that can quickly stabilize the polarization state of randomly changing signal light to a specific polarization state output,and proposes an improvement to the polarization control algorithm in the closed-loop control system,which improves the polarization state recovery speed and polarization accuracy Based on the embedded technology,a prototype of the polarization stabilizer was developed.The main research contents are as follows:1.Research on the stabilization method and control algorithm of light polarization state.Analyzed the theoretical basis and control principle of the light polarization state,designed a polarization stabilization system based on the polarization tracking detection scheme,and verified the scheme through mathematical modeling.The simulation verified the control effect of the polarization controller and proved the feasibility of the scheme;Research the system control algorithm,apply the simulated annealing algorithm to the polarization stabilization system,and propose improvements to the algorithm.The simulation verifies that the algorithm has the advantages of fast convergence,high control accuracy,and small stability fluctuations,and improves polarization Stabilize the speed while providing a theoretical basis for system design.2.Polarization stabilizer system design.Design the optical structure of the system,including the classification introduction and selection principle of the polarization controller,system input and output interface design,etc.;the signal acquisition and polarization control hardware circuit is designed with the STM32H750 microcontroller as the core,and the PCB production is completed;the system embedding is completed The system software is written in a form-factor,and the simulated annealing algorithm is applied to the actual polarization stabilization system to complete the closed-loop control system;the system hardware is mechanically packaged,and the polarization stabilizer prototype is completed.3.Test and analysis of polarization stabilizer.Based on the prototype of the polarization stabilizer,a test platform was built to verify the system.The experimental results show that the system can complete the stabilization of any input polarization state,and the polarization state recovery time is less than 3ms,and the polarization accuracy is controlled within 0.05 d B;In the continuous tracking experiment,when the input light polarization state changes randomly at 40π/s,the system can achieve better stability,and the output optical power fluctuation is less than 0.4d B;at the same time,the system has a wide input optical power range,at 5d Bm ～-35 d Bm input optical power,the system optical power loss is less than 1.2d B.