Research On The Influence Of Multifunctional Integrated Optical Component On The Temperature Bias Drift Of Fiber Optic Gyroscope

As an all-solid-state inertial instrument,the fiber optic gyroscope has significant advantages such as long life,high reliability and good adaptability to the space environment.At present,fiber optic gyroscopes are widely used in weapons and aerospace systems.At this stage,domestic high-precision fiber optic gyroscope technology has made great progress,but there are still many technical points that have not been completely broken.Among them,the zero offset drift of fiber optic gyroscope under temperature environment is the focus and hotspot of continuous research.As the core component of high-precision fiber optic gyroscope,the multi-functional integrated optical device,whose key performance parameters change with temperature,will cause the zero-bias drift of the fiber optic gyroscope.Therefore,this paper studies the temperature characteristics of the optical and electrical parameters of the multifunctional integrated optical device and its influence on the zero-bias drift of the fiber optic gyroscope.The main research contents are as follows:1.Through the study of the temperature characteristics of the optical parameters of the multifunctional integrated optical device,the mathematical models of the four optical parameters of spectral stability,polarization crosstalk,insertion loss and splitting ratio and the zero offset drift of the fiber optic gyroscope are established,and simulated and analyzed.The influence of the temperature characteristics of optical parameters on the zero-bias drift of the fiber optic gyroscope.The focus is on the changes of polarization crosstalk at full temperature and its influence on the zero-bias drift of the fiber optic gyroscope.The improvement measures for the alignment process and structure are proposed,which are effective It reduces the polarization crosstalk and the zero-bias drift of the fiber optic gyroscope at full temperature.2.Through the research on the temperature characteristics of the electrical parameters of the multifunctional integrated optical device,the mathematical models of residual intensity modulation,half-wave voltage,pyroelectric effect of Li Nb O3 crystal,waveform slope and zero offset drift of fiber optic gyroscope were established respectively,and simulated and analyzed.The influence of the electrical parameter changes of the multifunctional integrated optical device on the zero-bias drift of the fiber optic gyroscope under the temperature environment.The focus is on the change of the waveform slope at full temperature and its influence on the zero-bias drift of the fiber optic gyroscope,and electrode optimization measures are proposed.Effectively reduce the waveform slope and the zero-bias drift of the fiber optic gyroscope.3.Established a mathematical model of the temperature performance of the multifunctional integrated optical device parameters and the zero-bias drift of the fiber optic gyroscope.The temperature data of each parameter is fitted and calculated by the least square method,and the mathematical model of the temperature bias drift of the fiber optic gyroscope is simulated and verified by the polynomial modeling method.The simulation curve of the temperature offset drift of the fiber optic gyroscope caused by the multi-functional integrated optical device is obtained.The simulation results are consistent with the actual data of the fiber optic gyroscope’s full temperature test,which verifies the accuracy of the theoretical analysis.4.Measure the changes in the parameters of the multifunctional integrated optical device before and after the improvement at full temperature.The maximum polarization crosstalk is reduced from-25 d B to-30 d B,and the waveform slope is reduced from about 1% to within 0.25%.At the same time,measure The change in the zero-bias drift of the fiber optic gyroscope produced by the multifunctional integrated optical device before and after the improvement at full temperature.The experimental results before and after the improvement show that the zero-bias drift of the fiber optic gyroscope changes from 0.02°/h under the condition of-40℃~60℃.The left and right decrease to within 0.003°/h,which is an increase of about an order of magnitude.