Experimental Study Of Displacement Effect Of Erbium-doped Fiber Amplifier In The Space Radiation Environment

With the rapid development of modern space technology, the demand of satelliteinformation transmission capacity has increased. So that the satellite laser communi-cation with great information transmission capacity has broad application prospects thatinclude becoming the necessary spatial information infrastructure, the high resolutionreal time dynamic sureying transmission service of erath disaster, space opticalcommunication network on the ground, high speed communication technology.Satellite laser communication system requires large output power. On this basis,further improving the modulation rate is very difficult. Therefore we adopt themodulation with erbium-doped fiber amplifier (EDFA). However, satellite lasercommunication terminal is located in the space, the performance and parameters ofEDFA change obvious after cumulative radiation in the space radiation environment.The radiation effects of EDFA consist of ionization effect and displacement effect. Inthis paper, the displacement effect of EDFA in the space radiation environment isstudied theoretically and experimentally.This paper introduces status quo of temperature characteristic and radiation effect,analyses commonly used Saleh model of EDFA. The EDFA radiation model based onthe Saleh model is given which can describe fiber loss generated by radiation.In order to study the changes of gain of EDFA in different temperature environ-ment to apply EDFA better and reduce the radiation loss, first of all we study thetemperature characteristic. We measure the changes of gain of EDFA at the range of-196-75degrees c as background data that are also compared with the data afterradiation to study displacement effect of EDFA in the space radiation environment. Theexperimental results of displacement effect show that, the output of erbium-doped fiberdecreases by12-18dB and the output of WDM EDFA decreases by18-24dB afterradiation.The research work mentioned above reveals temperature characteristic of EDFAand the displacement effect of EDFA in the space radiaton environment. It will be agood reference for reducing the loss of EDFA caused by radiation and making EDFAbetter applied in satellite laser communication system.