光纤通信系统的性能与设计基础知识

1122334411„„„„„„„„„„„„„„„„„„„„1.11.1„„„„::0.850.85µµmm„„11.3.3µµmm„„11.55.55µµmmλλNNλλ11λλ22λλ33EDFAEDFAMUXMUXDEMUXDEMUXλλ11λλNNλλ33λλ221.21.2„„„„„„HubHubHubHubHub••1432NBusCATVCATVHDTVHDTV••1.31.3„„„„LANLAN„„BusBusRingRingStarStarCSMA/CDCSMA/CD1N-2N-1N2••••••••FDDIFDDILANLAN••2N-1N431Starcoupler••(())••••1122334455662213001300155015508508500.20.22.52.5((dB/km)dB/km)((nm)nm)OHOH••„„PPttPPrrααtottot(dB/km)(dB/km)„„PPrrBBhhννNNpp„„LLBB=rttotPPL10log10αBhNPprν=112233445566••::••::••••••••••33G.652G.652SMFSMF:::1300:1300nmnm15501550:16~17:16~17psps/nm.km/nm.kmG.653G.653DSFDSF:::1550:1550nmnmG.655G.655NZDSFNZDSF::1550nm1550nm:2~6:2~6psps/nm.km/nm.km„„„„1.0.851.0.85µµmm2.2.1.31.3µµmm„„1.31.3µµmmB1Gb/sB1Gb/sB1Gb/sB1Gb/s--------------3.3.1.551.55µµmm„„1.551.55µµmm„„1.551.55µµmmDD1717psps/(km/(km--nm)nm)••••••2.52.5GbGb/s/s,,••1010GbGb/s/s,,44dBmdBmconfLLCαα+=((dB/km)dB/km)0.1~0.20.1~0.2dB,dB,11dB)dB)SRTLMPPC−−=••••••••66--88dBdB::)(kmMPPLfconSRTαα−−−=((km)km)••1.31.3µµm.m.••PPTT==--4dBm4dBm••=0.3=0.35dB/km5dB/km••=1=1dBdB••APDAPD--36dBm36dBm=6=6dBdB••„„==--44––((--36)=32dB36)=32dB=0.3=0.35dB5dBxLxL=2=2dB(2dB(2,,11dB)dB)=6dB=6dB=(0.=(0.35L+2+6)dB35L+2+6)dB==(32(32--22--6)/0.356)/0.35km=km=68km68km(())