Ulusi wowoneka bwino ndi ulusi wowonekera wosinthika wopangidwa ndi galasi kapena pulasitiki wotuluka, womwe ndi wokhuthala pang'ono kuposa tsitsi la munthu. Optical fiber ndi njira yomwe imagwiritsidwa ntchito kwambiri potumizira kuwala kumapeto onse awiri, ndipo imagwiritsidwa ntchito kwambiri polumikizana ndi optical fiber. Chingwe chowonekera chimakhala ndi mtunda wautali wotumizira komanso bandwidth yapamwamba kuposa chingwe chawaya. Ulusi wowoneka bwino nthawi zambiri umakhala ndi chiwongola dzanja chochepa cha refractive-index ndi zotchingira zowonekera. Optical fiber imagwira ntchito ngati kondakitala yowunikira, yomwe imapangitsa kuwala kokwanira mu fiber core.
Nthawi zambiri, pali mitundu iwiri ya ulusi wa kuwala: yomwe imathandizira njira zingapo zofalitsira kapena njira zodutsa imatchedwa multimode fibers (MMF), ndipo yomwe imathandizira mawonekedwe amodzi amatchedwa single mode fibers (SMF). Koma pali kusiyana kotani pakati pawo? Kuwerenga nkhaniyi kukuthandizani kupeza yankho.
1. Kodi single-mode fiber ndi chiyani?
Mu optical fiber communication, single-mode fiber (SMF) ndi fiber optical yomwe imatumiza mwachindunji zizindikiro za kuwala mu lateral mode. Ulusi wamtundu umodzi umayenda pamlingo wa data wa 100M / s kapena 1 G / s, ndipo mtunda wotumizira ukhoza kufika pafupifupi makilomita 5. Nthawi zambiri, fiber single-mode imagwiritsidwa ntchito potumiza ma siginecha akutali.
2. Kodi ulusi wa multimode ndi chiyani?
Multimode fiber (MMF) imagwiritsidwa ntchito makamaka polumikizana ndi ulusi wakutali, monga mnyumba kapena masukulu. Chitsanzo kufala liwiro ndi 100M / s, kufala mtunda akhoza kufika 2km (100BASE-FX), 1 G / s akhoza kufika 1000m, 10 G / s akhoza kufika 550m. Pali mitundu iwiri ya index refractive: graded index ndi step index.
3. Kodi pali kusiyana kotani pakati pa single-mode ndi multimode fiber?
1. M'mimba mwake
Kusiyana kwakukulu pakati pa ma multimode ndi single-mode fiber ndikuti choyambirira chimakhala ndi mainchesi okulirapo, nthawi zambiri chimakhala chapakati pa 50 kapena 62.5 µm, pomwe ulusi wamtundu umodzi uli ndi mainchesi a 8 ndi 10 µm, phukusi la onse awiri. Miyeso yonseyo ndi 125µm.
2. Gwero la kuwala
Kawirikawiri laser ndi LED amagwiritsidwa ntchito ngati magwero a kuwala. Magwero a kuwala kwa laser ndi okwera mtengo kwambiri kuposa kuwala kwa LED chifukwa kuwala komwe kumatulutsa kumatha kuyendetsedwa bwino komanso kumakhala ndi mphamvu zambiri. Kuwala kopangidwa ndi magwero a kuwala kwa LED kumamwazikana (mitundu yambiri ya kuwala), ndipo magwero owunikirawa amagwiritsidwa ntchito kwambiri mu ma multimode fiber jumpers. Nthawi yomweyo, gwero la kuwala kwa laser (lomwe limatulutsa kuwala pafupi ndi njira imodzi) nthawi zambiri limagwiritsidwa ntchito ngati ma jumper amtundu umodzi.
3. Bandwidth
Chifukwa ulusi wa multimode uli ndi kukula kokulirapo kuposa ulusi umodzi wamtundu umodzi, umathandizira mitundu ingapo yotumizira. Kuonjezera apo, monga ulusi wa multimode, ulusi wamtundu umodzi umasonyezanso kufalikira kwa modal komwe kumayambitsidwa ndi mitundu yambiri ya malo, koma kufalikira kwa ma modal a single-mode fibers kumakhala kochepa kuposa ma multimode fibers. Pazifukwa izi, fiber ya single-mode imakhala ndi bandwidth yapamwamba kuposa fiber multimode.
4. Mtundu wa m'chimake
Mtundu wa jekete nthawi zina umagwiritsidwa ntchito kusiyanitsa ma multimode fiber jumpers kuchokera ku multimode fiber jumpers. Malinga ndi kutanthauzira kokhazikika kwa TIA-598C, pazogwiritsa ntchito zomwe si zankhondo, ulusi wamtundu umodzi wamtundu umodzi umagwiritsa ntchito jekete lakunja lachikasu, ndipo ulusi wamitundu yambiri umagwiritsa ntchito jekete lakunja lalalanje kapena la aqua-green. Malinga ndi mitundu yosiyanasiyana, opanga ena amagwiritsa ntchito chibakuwa kuti asiyanitse ulusi wa OM4 wapamwamba kwambiri ndi mitundu ina ya ulusi.
5. Modal kubalalitsidwa
Magwero a kuwala kwa LED nthawi zina amagwiritsidwa ntchito mu multimode fiber kupanga mndandanda wa mafunde omwe amafalikira pa liwiro losiyana. Izi zipangitsa kuti pakhale kubalalitsidwa kwamitundu yambiri, komwe kumachepetsa mtunda wotumizira ma multi-mode fiber jumpers. Mosiyana ndi izi, laser yomwe imagwiritsidwa ntchito poyendetsa chingwe chamtundu umodzi umatulutsa kuwala kumodzi. Chifukwa chake, kubalalitsidwa kwake modal ndikocheperako kuposa ulusi wa multimode. Chifukwa cha kubalalitsidwa kwa ma modal, fiber multimode imakhala ndi kuchuluka kwamphamvu kwambiri kuposa ulusi umodzi wamtundu umodzi, womwe umachepetsa mphamvu yotumizira uthenga wa fiber multimode.
6. Mtengo
Pakuti multimode CHIKWANGWANI angathe kuthandizira angapo kuwala modes, mtengo wake ndi apamwamba kuposa single mode CHIKWANGWANI. Koma pankhani ya zida, popeza fiber ya single-mode nthawi zambiri imagwiritsa ntchito ma laser diode olimba, zida za single-mode fiber ndizokwera mtengo kuposa zida za multimode fiber. Choncho, mtengo wogwiritsa ntchito multimode fiber ndi wochepa kwambiri kuposa mtengo wogwiritsira ntchito singlemode fiber.
4. Ndi fiber yamtundu wanji yomwe iyenera kusankhidwa?
Ganizirani za mtunda wotumizira komanso bajeti yonse. Ngati mtunda uli wochepera makilomita angapo, fiber multimode idzagwira ntchito bwino, ndipo mtengo wa njira yotumizira (transmitter ndi receiver) idzachokera ku 3300 yuan mpaka 5300 yuan. Ngati mtunda wophimbidwa ukuposa makilomita 6-10, ulusi wamtundu umodzi uyenera kusankhidwa, koma chifukwa cha kukwera mtengo kwa ma diode a laser, mtengo wamakina opatsirana nthawi zambiri umapitilira 6700 yuan.