Kev sib txuas lus fiber ntau, uas yog ib qho tseem ceeb ntawm kev sib txuas lus niaj hnub no, ua lub luag haujlwm tseem ceeb hauv kev sib txuas lus niaj hnub.
Txoj kev loj hlob ntawm kev sib txuas lus fiber ntau tuaj yeem xav tau los ntawm cov hauv qab no.
1.Yuav kom paub txog kev nce cov ntaub ntawv muaj peev xwm thiab kev sib kis mus ntev, ib hom fiber ntau uas tsis tshua muaj kev poob qis thiab tsis tshua muaj dispersion yuav tsum tau siv. Tam sim no, G.652 pa ib hom optical fiber ntau yog siv dav hauv kev sib txuas lus network optical cable kab. Txawm hais tias cov fiber ntau no muaj qhov tsawg kawg nkaus poob ntawm 1.55 μm, nws muaj qhov loj dispersion tus nqi ntawm 18 ps / (nm.km). Nws tau hais tias thaum cov pa ib hom fiber ntau siv ntawm lub wavelength ntawm 1.55 μm, qhov kev sib kis tsis zoo.
Yog tias xoom-dispersion wavelength hloov ntawm 1.31 μm mus rau 1.55 μm, nws yog hu ua dispersion-shifted fiber (DSF), tab sis thaum no fiber ntau thiab erbium-doped fiber amplifier (EDFA) yog siv nyob rau hauv lub wavelength division multiplexing system (WDM) , nws yuav Vim qhov tsis yog-linearity ntawm fiber ntau, plaub-yoj sib tov tshwm sim, uas tiv thaiv kev siv WDM, uas txhais tau hais tias xoom fiber ntau dispersion tsis zoo rau WDM.
Txhawm rau kom qhov kev sib txuas lus kho qhov muag fiber ntau tau ua tiav rau WDM system, cov fiber ntau dispersion yuav tsum raug txo, tab sis nws tsis tso cai rau xoom. Yog li ntawd, tus tshiab ib hom fiber ntau tsim yog hu ua non-zero dispersion fiber (NZDF), uas nyob ntawm 1.54 ~ Tus nqi dispersion nyob rau hauv 1.56μm ntau npaum li cas yuav tsum tau khaws cia ntawm 1.0 ~ 4.0ps / (nm.km), uas zam. qhov zero dispersion cheeb tsam, tab sis tswj tus nqi me me dispersion.
Ntau qhov piv txwv tau tshaj tawm rau pej xeem siv NZDF's EDFA / WDM kis tau tus mob.
2.Photonic li siv nyob rau hauv optical fiber kev sib txuas lus systems kuj tau tsim loj heev nyob rau hauv xyoo tas los. Txhawm rau ua kom tau raws li qhov xav tau ntawm WDM systems, ntau lub teeb pom kev zoo (MLS) tau tsim nyob rau xyoo tas los no. Nws tsuas yog npaj ntau lub raj laser hauv ib qho array thiab ua kom muaj kev sib xyaw ua ke kho qhov muag nrog lub hnub qub coupler.
Rau qhov tau txais qhov kawg ntawm qhov kev sib txuas lus fiber ntau optical, nws cov photodetector thiab preamplifier yog tsim los ntawm cov kev taw qhia ntawm high-speed los yog dav-band teb. PIN photodiodes tseem tuaj yeem ua tau raws li qhov yuav tsum tau ua tom qab kev txhim kho. Rau broadband photodetectors siv nyob rau hauv ntev-wavelength 1.55μm band, ib tug hlau semiconductor-hlau photodetection raj (MSM) tau tsim nyob rau hauv xyoo tas los. Taug kev nthwv dej faib photodetector. Raws li cov lus ceeb toom, MSM no tuaj yeem ntes 78dB ntawm 3dB zaus bandwidth rau 1.55μm lub teeb tsis.
FET lub preamplifier zoo li yuav raug hloov los ntawm lub siab hluav taws xob hloov hluav taws xob transistor (HEMT). Nws tau tshaj tawm tias 1.55μm optoelectronic receiver siv MSM detector thiab HEMT pre-amplified optoelectronic integration (OEIC) txheej txheem muaj ib zaus band ntawm 38GHz thiab xav kom ncav cuag 60GHz.
3. Lub point-to-point kis tau tus mob PDH system nyob rau hauv lub kho qhov muag fiber kev sib txuas lus system tsis muaj peev xwm hloov mus rau txoj kev loj hlob ntawm niaj hnub kev sib txuas lus network. Yog li ntawd, txoj kev loj hlob ntawm optical fiber kev sib txuas lus ntawm kev sib txuas lus tau dhau los ua ib qho kev hloov tsis tau.
SDH yog lub hom phiaj kev sib txuas lus tshiab tshiab nrog cov yam ntxwv ntawm kev sib txuas lus. Nws yog cov ntaub ntawv xov xwm thoob ntiaj teb uas sib koom ua ke multiplexing, kab sib kis thiab kev hloov pauv thiab muaj peev xwm tswj hwm lub network muaj zog. Nws yog tam sim no tau siv dav.