Research On Radiation Attenuation Of Erbium-doped Fiber In Laser Communication Terminal Under Space Irradiation

With the rapid development of satellite optical communications,erbium-doped fiber lasers(EDFL)and erbium-doped fiber amplifiers(EDFA)are used in more and more space applications.Because the space environment is very harsh and complex and changeable,it will have a serious impact on the devices of the on-board terminal.Among the various harsh environments in space,the space radiation environment has the greatest impact on the erbium-doped fiber devices,and the space radiation environment has the greatest impact on the erbium-doped fiber(EDF)in the erbium-doped fiber devices.Space radiation will cause the radiation loss of the erbium-doped fiber,deteriorate the performance of the fiber optic device,and may even cause permanent damage to it,which will seriously affect the operation of the terminal.Therefore,it is necessary to study the radiation attenuation of the erbium-doped fiber on the satellite terminal under space irradiation.This thesis first discusses the background and research significance of erbium-doped fiber radiation attenuation,then introduces the radiation environment of space,and briefly introduces the domestic research status of fiber radiation attenuation.Then,starting from the amplification mechanism of erbium-doped fiber,the most commonly used anti-radiation methods of optical fiber are analyzed,and the radiation effect of different radiation particles on optical fiber devices is analyzed.Then,the common fiber radiation attenuation model is briefly introduced and analyzed.Then through the specific mechanism analysis of the radiation attenuation loss of the erbium-doped fiber under different factors(irradiation conditions,temperature,working wavelength,optical power,fiber length and doping concentration,etc.),and obtain reasonable experimental conditions,through the model Perform simulation to analyze the relationship between the radiation attenuation of the fiber under different factors in low orbit,middle orbit and high orbit dose;through derivation and analysis of existing models,an integrated semi-empirical model is obtained.Finally,three different concentrations of erbium-doped fiber and erbium-ytterbium co-doped fiber(EYDF)were irradiated at different orbital doses through a 60 Co radiation source,and the experimental results were analyzed.The experiments were conducted through the power law model and the integrated semi-empirical model.Data fit,analyze and compare the fit of these two models.A semi-empirical model is used to predict and evaluate the lifetime of the optical fiber in the actual space environment of low orbit,middle orbit and high orbit.This paper analyzes the influence of different factors on the attenuation of optical fiber radiation in a comprehensive and in-depth manner.From the integration of the model and the analysis of the mechanism,the law of the attenuation of the optical fiber radiation of different factors is obtained,and the attenuation law of the optical fiber is analyzed through experiments.The service life of terminal erbium-doped fiber provides a reference and theoretical basis.