A Novel Ultra-Short Coil Fiber Optic Gyroscope

In the navigation of mankind on land,sea and air,navigation and positioning systems guide the way forward,of which inertial navigation plays a pivotal role.The fiber optic gyroscope as the core of inertial guidance is also the key research and development object of each country.With the increasing demand for small inertial devices in recent years,reducing the size to achieve miniaturization and integration of FOG will be the future development direction.This paper proposes a novel ultra-short coil FOG and gives a design scheme for the integration of FOG based on ultra-short coil structure,which provides an idea for the development of integrated,on-chip gyroscope.The specific research content is as follows:First,the research results of international research on miniaturized FOG and the development status of domestic in the field of integration were investigated.The structures and principles of I-FOG and R-FOG were analyzed based on the Sagnac effect principle.The signal modulation method of I-FOG is introduced,and the effect of fiber coil on FOG performance is analyzed in detail.Secondly,the modulation and demodulation principles of the spatial non-reciprocal phase modulator are derived from the electro-optical effect of Li Nb O₃ crystal.By analyzing the modulation of different types of modulated signals,the sawtooth wave phase modulation scheme is determined.And the advantages of this phase modulator in signal modulation and error suppression are analyzed.Thirdly,to verify the feasibility of the ultra-short coil FOG theory,we built an experimental prototype and made a detailed description of the parameters of the optical progenitors.The feasibility of the ultra-short coil theory is verified by the scalar factor test.The experimental results demonstrate that angular velocity measurements can still be achieved using low-frequency modulated signals in the ultra-short coil case.Finally,an integrated on-chip gyroscope design scheme is proposed based on the ultra-short coil FOG theory,combined with Ti diffusion waveguide and silicon-based optoelectronics technology.The feasibility of the scheme is demonstrated by analysis and simulation based on the optical waveguide theory.This provides an idea for the subsequent development of FOG towards miniaturization,integration and on-chip gyroscope.