1. Multimode fiber ntau
Thaum qhov loj me ntawm cov fiber (feem ntau yog lub hauv paus txoj kab uas hla d1) loj dua li qhov wavelength ntawm lub teeb (kwv yees li 1 µm), yuav muaj ntau kaum lossis ntau pua hom kev nthuav dav hauv cov fiber. Cov hom kev nthuav dav sib txawv muaj qhov ceev thiab theem sib txawv, ua rau lub sijhawm qeeb thiab ua kom nrov ntawm cov teeb pom kev zoo tom qab kev sib kis ntev. Qhov xwm txheej no hu ua modal dispersion (tseem hu ua intermodal dispersion). cov fiber optics.
Modal dispersion yuav ua rau cov bandwidth ntawm multimode fiber nqaim dua thiab txo nws lub peev xwm kis tau, yog li multimode fiber tsuas yog tsim rau kev sib txuas lus fiber optic me me.
Qhov kev faib tawm ntawm cov fiber ntau multimode yog parabolic, uas txhais tau tias nws muaj qib refractive index. Nws lub hauv paus txoj kab uas hla yog kwv yees li 50 µm.
2. Ib hom fiber ntau
Thaum qhov loj me ntawm cov fiber (feem ntau yog lub hauv paus txoj kab uas hla) tuaj yeem ze rau qhov ntev ntawm lub teeb, piv txwv li, lub hauv paus txoj kab uas hla d1 yog nyob rau hauv qhov ntau ntawm 5-10 µm, lub fiber tsuas yog tso cai rau ib hom (hom tseem ceeb HE11) kom nthuav dav hauv nws, thiab lwm cov hom kev txiav txim siab dua raug txiav tawm; cov fibers no hu ua cov fibers ib hom.
Vim tias nws tsuas muaj ib hom kev nthuav dav thiab zam qhov teeb meem ntawm hom kev faib tawm, ib hom fiber muaj bandwidth dav heev thiab tshwj xeeb tshaj yog tsim rau kev sib txuas lus fiber optic muaj peev xwm siab. Yog li ntawd, kom ua tiav ib hom kev sib kis, cov qauv fiber yuav tsum ua tau raws li qee yam mob. Nws yog xam siv cov mis uas rau ib lub fiber nrog NA = 0.12, kom ua tiav ib hom kev sib kis saum toj no λ = 1.3 µm, lub vojvoog ntawm lub fiber core yuav tsum yog ≤4.2 µm, uas yog, nws lub hauv paus txoj kab uas hla d1 ≤ 8.4 µm.
Vim tias lub hauv paus ntawm cov fiber ntau ib hom yog me heev, cov kev cai nruj dua raug yuam rau nws cov txheej txheem tsim khoom.
Lub sijhawm tshaj tawm: Lub Ib Hlis-10-2023
