Research On Optical Fiber Gyroscope Optical System Based On New Phase Modulator

In recent years,with the continuous innovation and development of information science and technology,the application field of fiber optic sensing technology has been expanding.As a core component of today’s inertial navigation systems,fiber optic gyro is a major achievement of the innovative combination of fiber optic sensing technology and inertial technology.At present,fiber optic gyro has a relatively perfect theoretical system and manufacturing process,but with the continuous improvement of the requirements for the measurement accuracy,volume and application scope of fog,the research on optical devices,optical path structure,modulation circuit,noise and error,process design and other aspects has been widely concerned.This paper proposes a new type of phase modulation structure that is not limited by the eigenfrequency.Based on its theoretical analysis and experimental verification,it focuses on the error simulation analysis of the optical path structure of the fiber optic gyroscope.The specific research content is as follows:Firstly,the domestic and foreign research background and development status of fiber optic gyro are introduced.Based on the Sagnac effect,the principle of speed measurement of fiber optic gyroscope is analyzed.The optical path structure and working principle of different types of fiber optic gyros are introduced,and the modulation methods of interferometric fiber optic gyros are analyzed and discussed in detail.Secondly,based on the electro-optical physical properties of lithium niobate crystals,a new phase modulator structure was designed and the relevant parameters of lithium niobate crystals were determined.By establishing the Jones matrix model of the phase modulator,the optical signal modulation law is obtained,which provides the necessary theoretical preparation for the optical path error analysis below.Thirdly,in order to verify the feasibility of the new phase modulator design,a new phase modulator and fiber optic gyroscope system are built,and the electro-optic modulation characteristics and temperature characteristics are tested and analyzed.The experimental results are in good agreement with the theoretical analysis,which shows the rationality and feasibility of the design scheme.Finally,based on the closed-loop optical path structure of the new phase modulator,the mathematical simulation model is established.And the influence of the parameters of each optical device in the optical path on the measurement results of the fog is discussed respectively,which provides a reference scheme for the realization of the high-precision measurement of the fog and lays the foundation for the optimization of the optical path in the next step.