4、eofthenumberofusersincreaseeveryyear,opticalfibercommunicationbecauseitcantransmithigh-speeddata,awide-areacommunicationsnetworkbackbonenetwork,Nowinwide-areacommunicationsnetworksformorethan80%oftheinformationistransmittedthroughopticalfibers.Butfromthe opticalfiber backbonenetwork tothe us