1. Keeb kwm ntawmfiber ntau hom
Ntau hom fiber ntau yog thawj qhov siv tau fiber ntau, nws lub vojvoog loj dua thiab ntau dua cov lej aperture hauv xyoo 1970s nrog LED lub teeb ci tsim thawj tiam ntawm kev sib txuas lus fiber ntau, siv nyob rau hauv kev sib txuas lus ntev thiab luv luv. Nrog rau qhov tshwm sim ntawm ib hom fiber ntau, ntau hom fiber ntau tom qab raug txwv rau cov ntawv thov luv luv vim tias tus nqi qis ntawm nws qhov system tag nrho.
Tus thawj multimode fiber ntau siv ib txoj kab uas hla ntawm 50um thiab tus txheeb ze refractive index sib txawv ntawm 1%. Vim yog qhov chaw loj heev ntawm LED, qhov tsim ntau hom fiber ntau tsis tuaj yeem ntes lub teeb lub zog ntawm LED, yog li 62.5um ntau hom fiber ntau tau tsim. 62.5um multi-mode fiber ntau muaj 2% txheeb ze refractive index sib txawv, thiab nws cov lej aperture kuj nce. Ntau lub teeb los ntawm LED yog txuas nrog rau ntau hom fiber ntau. Hauv nruab nrab xyoo 1990, tus nqi qis VCSEL laser tau tsim. Vim yog cov yam ntxwv ntawm lub teeb me me thiab cov lej aperture ntawm VCSEL nws tus kheej, ntau hom fiber ntau nrog ib txoj kab uas hla ntawm 50um nrog 1% txheeb ze qhov ntsuas qhov sib txawv tau rub rov qab rau daim ntawv thov dua, thiab tau siv dav hauv luv luv- deb optical fiber kev sib txuas lus txog tam sim no.
2. Cov qauv tsim ntawm ntau hom fiber ntau
Yuav kom tau txais qhov zoo tshaj plaws hom dispersion, lub refractive index faib ntawm cov pa multimode fiber ntau txais yuav cov duab ntawm parabola los yog ze-parabola. Rau bending resistant multimode fiber ntau, sab nrauv groove tsim feem ntau yog saws.
3. Cov yam ntxwv cuam tshuam rau bandwidth ntawmmultimode fiber ntau
Lub ntsiab tseem ceeb uas cuam tshuam rau bandwidth ntawm multimode fiber ntau yog fiber ntau thiab lub teeb ci.
Cov yam ntxwv ntawm optical fiber ntau muaj xws li cov khoom dispersion thiab hom dispersion.
Vim yog cov yam ntxwv ntawm cov multimode fiber ntau nws tus kheej, muaj txog li 19 hom pab pawg uas tuaj yeem xa mus rau hauv multimode fiber ntau, thiab qhov sib txawv ntawm cov qauv tuaj yeem loj heev yog tias tsis tswj tau meej. Yog siv VCSEL, hom dispersion feem ntau cuam tshuam los ntawm EMB ntawm kev siv bandwidth zoo; Yog tias siv LED, nws yog sawv cev los ntawm OFL BW ntawm kev txhaj tshuaj bandwidth tag nrho.
Hom kev ua tau zoo bandwidth thiab cov khoom tawg ntawm cov fiber ntau tuaj yeem tau txais los ntawm cov khoom siv fiber ntau ntawm cov chaw tsim khoom fiber ntau. Lub degree ntawm kev cuam tshuam ntawm lub bandwidth, hom bandwidth thiab cov khoom dispersion tsis muaj qhov loj, nyob ntawm seb lub teeb ci. Feem ntau hais lus, LED teeb qhov chaw thiab cov khoom tawg yog qhov tseem ceeb txwv ntawm kev sib txuas bandwidth. Rau VCSEL, hom bandwidth tam sim no yog qhov tseem ceeb txwv ntawm qhov txuas bandwidth.
Cov yam ntxwv ntawm lub teeb ci VCSEL tuaj yeem raug xa mus rau nws lub nplhaib flux EF (Encircled flux). Lub ntsiab txhais ntawm VCSEL's Encircled flux yog raws li nram no. Nws yog ib qho tseem ceeb ntawm lub teeb pom kev zoo raws li lub voj voog tseem ceeb, uas sawv cev rau kev faib tawm ntawm lub teeb lub zog ntawm txhua hom hauv cov tub ntxhais.
Kev faib tawm ntawm nws cov EF yuav tsum nyob hauv ob lub thawv liab hauv daim duab hauv qab no. Yog tias EF hla lub thawv liab ntawm sab xis, qhov txuas bandwidth yuav txo qis heev.
4. Multimode fiber ntaulink bandwidth ntsuam xyuas
Nws yog ib qho tseem ceeb heev los soj ntsuam qhov txuas bandwidth ntawm ntau hom fiber ntau thaum siv ntau hom fiber ntau rau kev faib khoom network, vim tias tus neeg siv tsis tuaj yeem kuaj tag nrho VCSEL lasers thiab tag nrho cov fibers ib qho los ntawm ib qho. Raws li cov kev qhia tshwj xeeb ntawm multimode fiber ntau thiab VCSEL laser, fiber ntau txuas bandwidth kev ntsuam xyuas yog pab kom paub txog qhov tsim qhov txuas bandwidth.
5. Multimode fiber ntau dilemma
Nrog rau qhov kev thov nce siab ntawm qhov siab bandwidth, ntau hom fiber ntau yuav tsis tuaj yeem ua tau raws li qhov kev thov nce ntawm bandwidth tus nqi hauv ob peb xyoos tom ntej no vim nws tus yam ntxwv. Ntxiv mus, kev tsim cov txheej txheem ntawm ntau hom fiber ntau nws tus kheej yog qhov nyuaj thiab nws tus nqi siab, uas feem ntau yog nyob ntawm VCSEL laser nrog tus nqi qis. Yog tias ib hom VCSEL lasers ntawm tib tus nqi tau dav dav hauv ob peb xyoos tom ntej no, nws yuav ua rau muaj kev hem thawj rau kev muaj ntau hom fiber ntau.
Lub neej yav tom ntej ntawm ntau hom fiber ntau yuav tsum ua kom tag nrho siv nws cov yam ntxwv ntau hom los nthuav dav daim ntawv thov ntau yam. Yog tias qhov no tuaj yeem kov yeej yav tom ntej, tej zaum keeb kwm yuav muab kauv los ntawmmulti-mode rau ib homthiab rov qab mus rau universal daim ntawv thov ntawm ntau hom.
