Design Of Light Source And Research On Its Impact On Fiber Optic Gyroscope

Interferometric Fiber Optic Gyroscope(IFOG)is playing an increasing important role as angular rate sensor in strapdown inertial navigation system for its obvious advantages such as simple production process,high stability,long service life,larger dynamic range and so on.The development in the performance of new light source also attaches great importance to the research of IFOG.In low precision engineering applications,superluminescent diode light source can meet the requirements;while in high precision applications,Erbium-doped Fiber Source(EFS)is the preferred source for high precision fiber optic gyroscope due to its good optical properties and temperature performance.The light source is a critical signal source of the IFOG sensor,thus its character determines the performance of IFOG.This paper is concentrate on investigating the relationship between light source and IFOG sensor.In this paper,the working principle of EFS used in high precision IFOG is given firstly,then the optical structure,circuit design as well as the analysis of how individual performance of EFS effects IFOG qualitatively and quantitatively of are illustrated.Finally,experiments are maintained to validate the effectiveness of the EFS system.The main works of this paper are given as follows.The design and implementation of optical circuit and electric circuit.After introducing the operation principle of EFS,the analysis of basic typical optical circuit structure is maintained.According to analysis result,bidirectional pumping ring light source optical circuit is obtained.Then,based on the functional requirements of the optical circuit structure,thermal control circuit,monitoring and protection circuit and constant current drive circuit are designed.Followed by,the corresponding control program is designed and realized.The effect of the light source to the performance of IFOG is studied.Started from the performance parameters of light source,the numerical calculation methods is given and based upon the calculation proposed methods a MATLAB GUIDE developed spectral analysis software is designed.After that,the impact from asymmetry of spectrum and mean wavelength to the scale factor of IFOG is analyzed.According to the analysis results,the requirements for coherence,thermal stability and asymmetry in light source and spectrum is obtained.Then the designed optical circuit and electric circuit in light source is debugged and the light source is experimented as a whole system.Experimental results shows that the designed light source's power is larger than 10 mW,mean wavelength stability is around 3ppm/?,the width of spectrum is larger than 35 nm,all the parameters meets the command for high-precision IFOG applications which validates our work's effectiveness.Finally,the experiments on scale factor of FOG in changing temperature environment is conducted to validate better performance of designed light source.