Koj yuav tsum nkag siab txog qhov txawv ntawm ib hom fiber thiab multimode fiber. Niaj hnub no, cia peb tham txog fiber optics uas siv los xa cov ntaub ntawv ua cov teeb liab optical. Muaj ob hom: ib hom thiab multimode. Tsab xov xwm no yuav npog ib hom thiab multimode pawg thiab kev ua tau zoo hauv kev nthuav dav, yog li txuas ntxiv kawm txog qhov txawv ntawm ib hom thiab multimode.

Ua ntej, tej zaum kuv yuav tsum xav txog qhov loj ntawm lub hauv paus. Kuv xav tias ib hom muaj lub hauv paus me dua, zoo li 9 microns, thaum multimode loj dua, tej zaum 50 lossis 62.5 microns. Qhov loj ntawm lub hauv paus yuav cuam tshuam rau qhov uas lub teeb mus ncig. Hauv ib hom, txij li thaum lub hauv paus me dua, tej zaum tsuas yog ib hom ntawm lub teeb tuaj yeem nthuav dav, yog li ntawd lub npe. Multimode yuav tso cai rau ntau hom. Tab sis "hom" txhais li cas ntawm no? Kuv xav tias hom yog txoj hauv kev uas lub teeb tuaj yeem hla lub fiber. Yog li hauv multimode, lub teeb tuaj yeem siv ntau txoj hauv kev, uas yuav ua rau muaj kev sib kis modal. Ntawd yog thaum ntau hom tuaj txog ntawm lub sijhawm sib txawv, ua rau muaj kev cuam tshuam ntawm lub teeb liab. Yog li ib hom, muaj tsuas yog ib txoj hauv kev, zam qhov no. Qhov ntawd yuav tsum txhais tau tias ib hom tuaj yeem tswj tau bandwidth siab dua ntawm qhov deb ntev dua.

Tiam sis tom qab ntawd, ua li cas txog lub teeb ci? Kuv xav tias ib hom siv lasers, uas yog qhov tseeb dua thiab tuaj yeem tsom lub teeb rau hauv lub hauv paus me dua. Multimode tej zaum yuav siv LEDs lossis lasers pheej yig dua vim tias lub hauv paus loj dua thiab yooj yim dua rau kev sib txuas lub teeb rau hauv. Lasers kim dua, yog li cov transceivers ib hom yuav kim dua li cov multimode.

Qhov deb yog lwm yam. Yog tias ib hom muaj tsawg dua qhov kev tawg, nws tuaj yeem mus deb dua yam tsis muaj teeb liab puas tsuaj. Multimode, nrog rau kev tawg modal, yuav muaj qhov deb luv dua. Tej zaum zoo li kilometers rau ib hom thiab ntau pua meters rau multimode? Tab sis kuv yuav tsum xyuas cov lej tseeb. Kuv tau hnov ​​​​​​cov lus zoo li OM3 thiab OM4 rau cov fibers multimode, uas cuam tshuam nrog lawv cov kev ua tau zoo. Cov ntawd yog tej zaum cov qauv rau ntau qib ntawm multimode, optimized rau qhov ceev dua ntawm qee qhov deb.

Bandwidth—ib hom yuav tsum muaj bandwidth siab dua vim tias tsis muaj modal dispersion. Yog li ntawd, rau kev sib txuas lus ceev ceev, ntev xws li ntawm cov nroog lossis hauv cov chaw sib txuas lus hauv telecom, ib hom zoo dua. Multimode siv rau hauv cov chaw khaws ntaub ntawv lossis cov tes hauj lwm hauv zos uas qhov deb luv dua, thiab tus nqi yog qhov txhawj xeeb loj dua.

Tus nqi ntawm cov fiber nws tus kheej: ib hom yuav zoo sib xws hauv tus nqi, tab sis cov transceivers (zoo li SFP modules) kim dua vim yog cov lasers. Multimode transceivers pheej yig dua, tab sis cov fiber yuav kim dua me ntsis? Tos, tsis yog, kuv xav tias ib hom fiber yeej pheej yig dua hauv qee kis vim nws yooj yim dua? Lossis tej zaum tus nqi teeb tsa txawv. Tos, kev teeb tsa yuav nyuaj dua rau ib hom vim tias lub hauv paus me dua, xav tau cov khoom sib txuas thiab kev sib dhos meej dua. Qhov ntawd tuaj yeem ua rau kev teeb tsa kim dua, txawm tias cov fiber nws tus kheej tsis yog.

Cov ntawv thov: ib hom rau kev deb, telecom, ISPs. Multimode rau LANs, data centers, campus networks. Tsis tas li ntawd, tej zaum nyob rau hauv cov xwm txheej uas xav tau bandwidth siab tab sis dhau qhov kev khiav luv dua. Zoo li txuas cov servers hauv lub chaw khaws ntaub ntawv.

Cov Wavelengths siv: Ib hom feem ntau siv 1310 nm thiab 1550 nm, thaum multimode yuav siv 850 nm thiab 1300 nm. Cov wavelengths ntev dua hauv ib hom yuav muaj qhov attenuation qis dua, pab txhawb kom ncav cuag ntev dua.

Kuj tseem muaj qee yam txog kev tawg ntawm chromatic, uas cuam tshuam rau ib hom ntau dua li qhov deb heev, tab sis lawv siv cov fibers dispersion-shifted lossis compensators. Multimode qhov teeb meem tseem ceeb yog modal dispersion, uas tau txo qis los ntawm kev siv cov fibers graded-index qhov twg cov refractive index hloov maj mam, txo cov modal dispersion piv rau cov kauj ruam-index.

Auj, thiab muaj ntau hom fibers multimode, xws li OM1, OM2, OM3, OM4, OM5. Txhua tus muaj peev xwm sib txawv ntawm bandwidth thiab qhov deb. OM3 thiab OM4 tau zoo rau kev siv nrog 850 nm VCSELs (vertical-cavity surface-emitting lasers) rau qhov ceev dua xws li 10G, 40G, 100G Ethernet. OM5 yog rau wavelength division multiplexing hauv multimode.

Yog li muab qhov no ua ke: qhov loj me ntawm lub hauv paus, lub teeb ci, qhov deb, bandwidth, tus nqi, daim ntawv thov, thiab cov qauv. Ib hom rau kev mus ntev, tus nqi siab, kev ua tau zoo siab. Multimode rau qhov deb luv luv, tus nqi qis dua, yooj yim rau kev teeb tsa tab sis txwv los ntawm kev sib kis modal.

Kuv kuj yuav tsum xyuas seb puas muaj lwm qhov sib txawv, xws li khoov vojvoog lossis ua haujlwm tau ntev. Tej zaum ib hom yuav rhiab heev rau khoov vim yog lub hauv paus me dua, tab sis kuv tsis paub meej. Multimode yuav zam txim ntau dua hauv qhov ntawd. Tsis tas li ntawd, kev sib raug zoo nrog cov khoom siv uas twb muaj lawm. Yog tias lub network twb siv multimode lawm, kev txhim kho yuav xav tau hloov ob qho tib si fiber thiab transceivers.

Lwm qhov taw tes: kev tiv thaiv yav tom ntej. Ib hom kev sib txuas lus ib leeg yuav ua tau ntau dua rau kev nce ceev yav tom ntej yam tsis tau hloov cov fiber, thaum multimode yuav muaj kev txwv vim tias bandwidth xav tau ntau dua li qhov fiber tuaj yeem ua nrog modal dispersion.

Tos, tab sis nrog kev nce qib hauv multimode zoo li OM5, tej zaum lawv tuaj yeem tswj tau qhov ceev dua ntawm qhov luv luv. Yog li qhov kev xaiv nyob ntawm qhov kev siv tshwj xeeb thiab kev loj hlob uas xav tau.

Kuv yuav tsum muab cov no sib piv ua ke. Tej zaum pib nrog qhov sib txawv tseem ceeb, tom qab ntawd mus rau cov ntsiab lus xws li bandwidth, qhov deb, tus nqi, daim ntawv thov, thiab lwm yam. Tsis tas li ntawd, suav nrog cov lus qhia luv luv rau kev siv sai.

Cia kuv xyuas qee tus lej. Ib hom tub ntxhais yog 8-10 microns, multimode 50 lossis 62.5. Ib hom siv cov chaw laser (1310, 1550 nm), multimode siv LED / VCSEL (850, 1300 nm). Qhov deb tshaj plaws: ib hom tuaj yeem mus txog kaum tawm kilometers, txawm tias 100 km nrog cov khoom siv tsim nyog. Multimode rau 100M txog 550m nyob ntawm tus qauv (OM3 / OM4). Tus nqi: ib hom transceivers kim dua, tab sis tus nqi fiber sib piv lossis siab dua me ntsis? Lossis tej zaum lub fiber pheej yig dua, tab sis tag nrho cov nqi system siab dua vim yog transceivers.

Tsis tas li ntawd, bandwidth: ib hom muaj bandwidth tsis txwv rau cov hom phiaj siv tau, thaum multimode raug txwv los ntawm modal dispersion. Yog li rau 10G, 40G, 100G, multimode tuaj yeem tswj nws tab sis hla qhov luv dua. Ib hom tuaj yeem tswj cov kev ceev ntawd hla qhov ntev dua.

Hais txog cov qauv, ib hom yog them los ntawm ITU-T G.652, G.653, thiab lwm yam, thaum multimode yog TIA-492-AAAB (OM1), thiab lwm yam.

Kev teeb tsa thiab kev saib xyuas: ib hom xav tau kev ua haujlwm ntau dua, yog li tej zaum yuav muaj kev ua haujlwm txawj ntau dua, tus nqi teeb tsa thawj zaug siab dua. Multimode yooj yim dua rau kev ua haujlwm nrog, tus nqi teeb tsa qis dua.

Yog li ntawd, qhov kev sib piv tag nrho yuav npog tag nrho cov yam no. Tej zaum kuj hais txog kev hloov pauv, zoo li ib hom kev siv tau ntau dua txawm tias nyob rau hauv qhov deb luv dua vim yog tus nqi ntawm optics txo qis, tab sis multimode tseem tuav tau hauv cov nqi-rhiab, luv luv- ncav cuag scenarios.