Lub hauv paus qauv ntawm optical fiber
Qhov liab qab fiber ntau ntawm optical fiber feem ntau muab faib ua peb txheej: core, cladding thiab txheej.
Cov tub ntxhais fiber ntau thiab cladding yog tsim los ntawm iav nrog sib txawv refractive indexes, qhov chaw yog ib tug siab refractive index iav core (germanium-doped silica), thiab nruab nrab yog ib tug tsawg refractive index silica iav cladding (ntshiab silica).Lub teeb nkag mus rau hauv cov fiber ntau ntawm ib lub kaum ntse ntse ntawm qhov xwm txheej, thiab tag nrho cov emission tshwm sim ntawm fiber ntau thiab cladding (vim qhov refractive index ntawm cladding yog me ntsis qis dua cov tub ntxhais), yog li nws muaj peev xwm propagate nyob rau hauv fiber.
Lub luag haujlwm tseem ceeb ntawm cov txheej yog los tiv thaiv cov fiber ntau optical los ntawm kev puas tsuaj rau sab nraud, thaum ua kom yooj yim ntawm cov fiber ntau optical.Raws li tau hais ua ntej, cov tub ntxhais thiab cladding yog ua los ntawm iav thiab tsis tuaj yeem khoov thiab tawg.Kev siv cov txheej txheej tiv thaiv thiab ua kom lub neej ntev ntawm cov fiber ntau.
Ib txheej ntawm txheej sheath yog ntxiv rau cov uas tsis yog liab qab.Ntxiv nrog rau kev tiv thaiv nws, cov ntaub qhwv sab nrauv ntawm cov xim sib txawv kuj tuaj yeem siv los paub qhov txawv ntawm ntau yam fibers.
Optical fiber tau muab faib ua ib hom fiber ntau (Single Mode Fiber) thiab multimode fiber (Multi Mode Fiber) raws li hom kev sib kis.Lub teeb nkag mus rau hauv fiber ntau ntawm lub kaum sab xis ntawm qhov xwm txheej, thiab tag nrho emission tshwm sim ntawm fiber ntau thiab cladding.Thaum txoj kab uas hla me me, tsuas yog ib qho kev taw qhia ntawm lub teeb raug tso cai hla dhau, uas yog, ib hom fiber ntau;thaum lub fiber ntau txoj kab uas hla loj, lub teeb tuaj yeem tso cai.Txhaj thiab nthuav tawm ntawm ntau qhov xwm txheej, lub sijhawm no nws yog hu ua multimode fiber.
Optical fiber kis tau tus mob
Optical fiber ntau muaj ob yam tseem ceeb kis tau tus mob: poob thiab dispersion.Qhov poob ntawm ib qho fiber ntau yog hais txog qhov attenuation ib chav tsev ntev ntawm qhov kho qhov muag fiber, hauv dB / km.Cov qib ntawm optical fiber ntau poob ncaj qha cuam tshuam qhov kev ncua deb ntawm qhov kev sib txuas lus fiber ntau optical lossis qhov kev ncua deb ntawm qhov chaw relay.Fiber dispersion yog hais txog qhov tseeb tias cov teeb liab kis tau los ntawm fiber ntau yog nqa los ntawm cov khoom sib txawv thiab cov khoom sib txawv, thiab qhov sib kis ceev ntawm cov khoom sib txawv thiab cov khoom sib txawv ntawm cov khoom sib txawv, uas ua rau cov teeb liab distortion.
Fiber dispersion yog muab faib ua cov khoom dispersion, waveguide dispersion thiab modal dispersion.Thawj ob hom dispersion yog tshwm sim los ntawm lub teeb liab tsis yog ib zaus, thiab tom kawg ntawm dispersion yog tshwm sim los ntawm lub teeb liab tsis yog ib hom.Lub teeb liab tsis yog ib hom yuav ua rau hom dispersion.
Ib hom fiber ntau muaj tsuas yog ib qho tseem ceeb hom, yog li tsuas yog cov khoom dispersion thiab waveguide dispersion, thiab tsis muaj modal dispersion.Lub multimode fiber muaj inter-mode dispersion.Lub dispersion ntawm optical fiber tsis tsuas yog cuam tshuam lub peev xwm kis tau tus mob ntawm optical fiber, tab sis kuj txwv qhov kev ncua deb ntawm lub optical fiber kev sib txuas lus system.
Ib hom fiber ntau
Tib hom fiber ntau (Single Mode Fiber), lub teeb nkag mus rau hauv fiber ntau ntawm lub kaum ntse ntse tshwj xeeb, thiab tag nrho emission tshwm sim ntawm fiber ntau thiab cladding.Thaum txoj kab uas hla luv luv, tsuas yog ib qho kev taw qhia ntawm lub teeb raug tso cai hla dhau, uas yog, ib hom fiber ntau;Lub hauv paus iav tseem ceeb ntawm hom fiber ntau yog nyias, cov kab uas hla feem ntau yog 8.5 lossis 9.5 μm, thiab nws ua haujlwm ntawm 1310 thiab 1550 nm wavelengths.
Multimode fiber ntau
Ntau hom fiber ntau (Ntau hom Fiber) yog fiber ntau uas tso cai rau ntau hom kev sib kis.Cov tub ntxhais txoj kab uas hla ntawm multimode fiber ntau yog 50μm / 62.5μm.Vim hais tias cov tub ntxhais txoj kab uas hla ntawm ib tug multimode fiber ntau kuj loj, nws muaj peev xwm cia ntau hom teeb kis tau tus mob ntawm ib fiber.Tus qauv wavelengths ntawm multimode yog 850nm thiab 1300nm feem.Kuj tseem muaj tus qauv tshiab multimode fiber ntau hu ua WBMMF (Wideband Multimode Fiber), uas siv wavelengths ntawm 850nm thiab 953nm.
Ob leeg hom fiber ntau thiab ntau hom fiber ntau muaj ib txoj kab uas hla ntawm 125 μm.
Ib hom fiber ntau lossis ntau hom fiber ntau?
Kev sib kis nrug
Qhov me me txoj kab uas hla ntawm ib hom fiber ntau ua rau qhov kev xav tau nruj dua, cia tsuas yog ib hom ntawm lub teeb mus ncig, kom cov teeb liab kho qhov muag tuaj yeem mus deb dua.Raws li lub teeb dhau los ntawm lub hauv paus, cov nyiaj ntawm lub teeb pom kev txo qis, txo qis attenuation thiab ua rau muaj teeb meem ntxiv.Vim nws tsis muaj inter-mode dispersion lossis me me inter-mode dispersion, ib hom fiber ntau tuaj yeem xa 40 mais lossis ntau dua yam tsis muaj kev cuam tshuam rau lub teeb liab.Yog li ntawd, ib hom fiber ntau feem ntau yog siv rau kev xa cov ntaub ntawv mus ntev thiab tau siv dav hauv cov tuam txhab kev sib txuas lus thiab cov chaw muab kev pabcuam cable TV thiab cov tsev kawm qib siab, thiab lwm yam.
Multimode fiber ntau muaj ib txoj kab uas hla loj dua thiab tuaj yeem xa lub teeb rau ntau hom.Hauv ntau hom kev sib kis, vim qhov loj me me, qhov sib txawv ntawm qhov sib txawv yog qhov loj dua, uas yog, cov teeb liab kho qhov muag "kis" sai dua.Lub teeb liab zoo yuav raug txo qis thaum lub sijhawm sib kis mus ntev, yog li ntau hom fiber ntau feem ntau yog siv rau luv luv, daim ntawv thov audio / video thiab cov chaw hauv cheeb tsam (LANs), thiab OM3 / OM4 / OM5 ntau hom fiber ntau tuaj yeem txhawb nqa siab. - ceev cov ntaub ntawv kis tau tus mob.
Bandwidth, muaj peev xwm
Bandwidth txhais tau tias yog lub peev xwm nqa cov ntaub ntawv.Lub ntsiab tseem ceeb uas cuam tshuam rau qhov dav ntawm optical fiber ntau kis tau tus mob yog ntau yam dispersions, ntawm uas modal dispersion yog qhov tseem ceeb tshaj plaws.Lub dispersion ntawm ib hom fiber ntau yog me me, yog li nws muaj peev xwm kis tau lub teeb nyob rau hauv ib tug dav zaus band rau ib tug ntev nyob deb.Txij li thaum ntau hom fiber ntau yuav tsim kev cuam tshuam, cuam tshuam thiab lwm yam teeb meem nyuaj, nws tsis zoo li ib hom fiber ntau hauv bandwidth thiab muaj peev xwm.Cov tiam tshiab ntawm ntau hom fiber ntau bandwidth OM5 tau teeb tsa rau 28000MHz / km, thaum ib hom fiber ntau bandwidth loj dua.