Cov ntaub ntawv chaw tau dhau los ua lub cav ntawm lub neej niaj hnub; cov ntaub ntawv sib txuas ntxiv tau xa mus thiab khaws cia ntawm kev kub ceev los ntawm cov ntaub ntawv chaw. Feem ntau ntawm cov kev sib txuas hauv cov ntaub ntawv chaw yog luv luv, xws li los ntawm ob peb meters mus rau ob peb puas meters. Nyob rau hauv cov luv luv no thiab kev sib txuas lus ceev cov ntaub ntawv,Multimode fiber ntau thiab optical module nrog VCSELraws li cov tub ntxhais ntaus ntawv tau dav siv. Piv nrog rau cov phiaj xwm kev sib kis ib leeg, cov tswv yim ntau hom tau txais cov nqi qis thiab qis zog laser kom paub ceev thiab ua tau zoo sib txuas ntawm fiber ntau thiab laser. Ntau hom fiber ntau tuaj yeem ua tiav qhov sib kis tau zoo dua lossis ntev dua kev sib kis ntau dua li tooj liab cable thiab tus nqi qis dua ib hom fiber ntau. Tam sim no, qhov kev sib txuas sab hauv ntawm cov ntaub ntawv chaw yog twb100 Gbit / s, thiab 400Gbit / s yuav tsum sai sai no. Kev lag luam tau tsim tshiab multimode fiber ntau los txhim kho nws cov kev ua tau zoo, suav nrog WDM hauv ib qho fiber ntau. Ntev yoj multimode fiber ntau txhawb kev sib kis ntev dua. Tsis tas li ntawd, txhawm rau txhawm rau txhawb nqa kev sib txuas siab, kev sib txuas me me, txhim kho qhov chaw siv tus nqi, kev siv hluav taws xob ua kom sov thiab kev tswj xyuas cable ntawm cov ntaub ntawv chaw, ntau hom fiber ntau nrog khoov tsis kam tau tsim thiab xa tawm sai. Nyob rau hauv daim ntawv no, txoj kev loj hlob qauv ntawm multimode fiber txhawb kev kub ceev kho qhov muag module yog tham los ntawm combining cov kev cai ntawm multimode fiber ntau thiab evolution ntawm optical module technology.
1. Multi-mode optical fiber technology thiab daim ntawv thov scenarios
Txoj kev loj hlob ntawm huab xam tau txhawb txoj kev loj hlob ntawm super-loj cov ntaub ntawv chaw zov me nyuam, yog li tsim kom muaj kev sib txawv ntawm kev loj hlob ntawm cov chaw lag luam cov ntaub ntawv ib txwm muaj. Txawm hais tias nyob hauv lossis thoob ntiaj teb, kev hloov pauv ntawm cov chaw nres nkoj server tus nqi los ntawm cov neeg siv ntawm VLCC nrog cov kev pabcuam huab cua yog pom tseeb sai dua li cov chaw lag luam cov ntaub ntawv ib txwm muaj. Cov lag luam ib txwm yuav tsis tu ncua siv ntau hom OM4 fiber ntau, thiab ntau dua 90 feem pua ntawm cov kab ke txuas ntev yog tsawg dua 100m.
Cov neeg siv ntawm cov chaw zov me nyuam loj loj muaj feem ntau xaiv ib hom fiber ntau, thiab 70 feem pua ntawm cov kab txuas txuas ntev yog tshaj 100m. Txoj kev loj hlob ntawm super-loj cov ntaub ntawv chaw tau txhim kho qhov kev siv ntawm ib hom fiber ntau, tab sis ntau hom fiber ntau tseem muaj nws qhov tshwj xeeb zoo. Cov txiaj ntsig zoo no suav nrog kev muaj cov nqi kho qhov muag qis dua, kev siv hluav taws xob qis dua, thiab kev sib kis sib kis uas npog feem ntau ntawm cov kev sib txuas hauv cov ntaub ntawv chaw, yog li kev daws teeb meem raws li multimode fiber ntau thiab multimode optical modules tseem txaus nyiam rau cov neeg siv khoom.
2. Bandwidth ntawm 850 nm multimode fiber ntau
Qhov sib txawv ntawm ib hom kab ke, qhov sib kis nrug thiab tus nqi ntawm ntau hom kab ke raug txwv los ntawm bandwidth ntawm ntau hom fiber ntau. Lub hom bandwidth ntawm multimode fiber ntau yuav tsum tau nce ntxiv los txhawb qhov kev ncua deb ntawm kev kub ceev.
Nrog rau kev tsim fiber ntau tsim thiab tsim, bandwidth ntawm multimode fiber ntau tau txhim kho zoo heev. Lub 62.5μm multimode fiber ntau muaj cov lej aperture siab thiab cov tub ntxhais fiber ntau, uas tuaj yeem ua ob lub teeb-emitting diode (LED) lub teeb ci rau hauv fiber ntau thiab txhawb nqa cov ntaub ntawv xa mus ntawm 2km ntawm tus nqi ntawm 10 Mbit / s lossis txawm tias 100 Mbit / s. Nrog rau kev txhim kho ntawm Ethernet tus qauv thiab tus nqi qis 850nm VCSEL, ntau hom fiber ntau nrog cov tub ntxhais txoj kab uas hla ntawm 50 micron fiber ntau yog nrov nyob rau hauv kev ua lag luam. Cov fiber ntau muaj qis hom dispersion thiab siab dua bandwidth, thiab VCSEL qhov chaw loj thiab cov lej aperture yog me dua li LED's, tso cai rau lub laser tau yooj yim txuas rau hauv 50 micron fiber. Los ntawm kev ua kom zoo ntawm cov txheej txheem kho qhov muag fiber ntau thiab siv cov thev naus laus zis thev naus laus zis thev naus laus zis, 50μm multimode optical fiber ntau tsim los ntawm OM2 (500 MHz * Km) rau OM3 (2 000 MHz * Km), thiab tam sim no tau tsim rau OM4 ({ {17}} MHz * Km).
Rau ntau hom kab ke siv 850 nm VCSEL, ntxiv kev nce bandwidth ntawm OM4 multi-mode fiber ntau tsis tuaj yeem ua rau cov khoom siv kho qhov muag xa mus deb ntxiv, vim tias lub kaw lus bandwidth nyob ntawm kev sib xyaw ua ke ntawm cov txiaj ntsig bandwidth ntawm cov fiber ntau thiab cov dispersion ( uas muaj feem xyuam rau txoj kab dav dav ntawm VCSEL laser thiab wavelength ntawm fiber ntau). Yog hais tias lub kaw lus bandwidth yuav tsum tau nce, ntxiv rau qhov zoo hom bandwidth ntawm fiber ntau, tus nqi dispersion yuav tsum tau optimized. Qhov no tuaj yeem ua tiav los ntawm kev siv hom sib txawv ncua sij hawm (DMD) multimode fiber ntau los them nyiaj rau ib nrab dispersion, lossis los ntawm kev siv txoj kab nqaim dav ntawm 850nm VCSEL lossis ua haujlwm hauv thaj tsam yoj ntev dua nrog qis qis.
Qhov siab tshaj plaws txheeb ze refractive index ntawm cov tub ntxhais fiber ntau kuj cuam tshuam rau qhov siab tshaj plaws bandwidth. Thaum cov tub ntxhais poob los ntawm 1 feem pua rau 0.75 feem pua, bandwidth doubles. Txawm li cas los xij, kev txo cov tub ntxhais fiber ntau yuav ua rau muaj qhov khoov poob, yog li nws yog qhov yuav tsum tau ua kom zoo dua cov qauv fiber ntau los txhim kho nws txoj kev khoov.
3. Khoov-insensitive multimode fiber ntau
Nyob rau hauv cov ntaub ntawv chaw siv, khoov-insensitive multimode fiber ntau thiab ntau lug siv, uas yuav optimize tus tsim ntawm optical fiber, kho vajtse thiab khoom siv kom txuag tau ntau qhov chaw, muaj cua txias efficiency thiab ntau yooj yim kev twb kev txuas thiab cable tswj. Lub hauv paus yog graded index, thiab cov cladding muaj ib tug qis index groove. Qhov zawj txo cov hluav taws xob kho qhov muag hauv cov cladding thiab tuaj yeem tiv thaiv cov xau ntawm cov teeb liab kho qhov muag, yog li txhim kho qhov kev ua tau zoo ntawm cov fiber ntau. Fiber tsim optimizes cov tub ntxhais thiab zawj qhov loj ntawm cov fiber ntau, thiab ua tiav qhov sib npaug ntawm kev khoov kev ua haujlwm thiab kev sib raug zoo nrog cov qauv multimode fiber ntau. Los ntawm kev tsim tsim nyog ntawm cov tub ntxhais fiber ntau thiab zawj, multimode fiber ntau tuaj yeem ua tiav OM4 qib siab bandwidth thiab qis khoov poob. Qhov macro bending poob ntawm dabtsi yog khoov-insensitive multimode fiber ntau yog ntau tshaj 10 npaug qis dua li cov qauv multimode fiber ntau.
