Single-mode fiber (SingleModeFiber) ndi chingwe cha kuwala chomwe chimatha kufalitsa mawonekedwe amodzi pa utali wotchulidwa. Pakatikati pagalasi pachimake ndi woonda kwambiri (pakati m'mimba mwake nthawi zambiri ndi 9 kapena 10μm).
Choncho, kubalalitsidwa kwake kwapakati-mode kumakhala kochepa kwambiri, koyenera kulankhulana kwakutali Komabe, palinso kubalalitsidwa kwakuthupi ndi kufalikira kwa waveguide, kotero kuti ulusi wamtundu umodzi uli ndi zofunikira zapamwamba pamtundu wa spectral ndi kukhazikika kwa gwero la kuwala, ndiko kuti, m'lifupi spectral ayenera kukhala yopapatiza ndi bata ndi bwino.
Pambuyo pake, zinapezeka kuti pa 1.31μm wavelength, kufalikira kwa zinthu za fiber single-mode optical fiber ndi kufalikira kwa waveguide ndi zabwino ndi zoipa, ndipo kukula kwake kuli chimodzimodzi. Mwanjira imeneyi, dera la 1.31μm wavelength lakhala zenera loyenera logwirira ntchito pazolumikizana ndi ma fiber optical, ndipo tsopano ndilo gulu lalikulu la machitidwe ogwiritsira ntchito optical fiber communication. Magawo akuluakulu a 1.31μm wamba wamtundu umodzi amalimbikitsidwa ndi International Telecommunication Union ITU-T ku G652 Certain, kotero kuti fiber iyi imatchedwanso G652 fiber. Ulusi wamtundu umodzi ukhoza kugawidwa mu 652 single-mode fiber, 653 single-mode fiber ndi 655 single-mode fiber.
Kufotokozera kwa "single-mode fiber" m'mabuku a maphunziro: nthawi zambiri, pamene v ili pansi pa 2.405, nsonga imodzi yokha ya fiber imadutsa, choncho imatchedwa fiber-mode fiber. Pakatikati pake ndi woonda kwambiri, pafupifupi ma microns 8-10, ndipo kubalalitsidwa kwamachitidwe ndikochepa kwambiri. Chinthu chachikulu chomwe chimakhudza kukula kwa gulu la fiber transmission ndikusiyana kosiyana, ndipo kubalalitsidwa kwamachitidwe ndikofunikira kwambiri. Kubalalika kwa fiber ya single-mode ndi yaying'ono, kotero imatha kufalitsa kuwala mu gulu lafupipafupi kwa mtunda wautali.
Ulusi wamtundu umodzi uli ndi mainchesi apakati a 10 micron, omwe amalola kufalitsa kwamtundu umodzi, komwe kumatha kuchepetsa bandwidth ndi Modal Dispersion. Komabe, chifukwa single-mode fiber core diameter ndi yaying'ono kwambiri, ndizovuta kuwongolera kufalikira kwa mtengo, chifukwa chake ndikofunikira kuti ma lasers okwera mtengo amagwiritsidwa ntchito ngati gwero la kuwala, ndipo cholepheretsa chachikulu cha zingwe zamtundu umodzi ndikubalalika kwazinthu. . Zingwe za single-mode Optical zimagwiritsa ntchito ma lasers kuti apeze bandwidth yothamanga kwambiri. Popeza ma LED amatulutsa kuwala kochulukirapo kokhala ndi ma bandwidths osiyanasiyana, zofunikira zobalalika zakuthupi ndizofunikira kwambiri. Ulusi wamtundu umodzi ukhoza kuthandizira mtunda wautali wotumizira kuposa ulusi wamitundu yambiri. Mu 100Mbps Efaneti kapena 1G Gigabit netiweki, single-mode CHIKWANGWANI angathandizire kufala mtunda woposa 5000m kuchokera mtengo amaonera. Kuchokera pakuwona mtengo, popeza transceiver optical ndi okwera mtengo kwambiri, mtengo wogwiritsira ntchito single-mode optical fiber udzakhala wapamwamba kusiyana ndi mtengo wa multi-mode optical fiber cable.
Kugawa kwa index ya refractive ndikofanana ndi ulusi wowoneka bwino, mainchesi ake ndi 8 ~ 10μm, ndipo kuwala kumafalikira mumzere wozungulira mozungulira pakatikati. Chifukwa fiber iyi imatha kutumiza njira imodzi yokha (zigawo ziwiri za polarization ndizochepa), zimatchedwa fiber-mode fiber ndipo kupotoza kwake kumakhala kochepa kwambiri.