Lokacin yin kebul, a waɗanne yanayi ya kamata a yi amfani da fiber mai yanayi ɗaya kuma a waɗanne yanayi ya kamata a yi amfani da fiber mai yanayin multimode?

1. Zaren multimode

Idan girman zare (musamman diamita na tsakiya d1) ya fi girma fiye da tsawon haske (kusan 1 µm), za a sami hanyoyi da dama ko ma daruruwan yaɗuwa a cikin zare. Hanyoyin yaɗuwa daban-daban suna da saurin yaɗuwa da matakai daban-daban, wanda ke haifar da jinkiri na lokaci da faɗaɗa bugun gani bayan watsawa mai nisa. Wannan lamari ana kiransa yaɗuwar modal (wanda kuma aka sani da yaɗuwar intermodal). fiber optics.

Watsawar Modal zai rage girman zare mai yawa kuma ya rage ƙarfin watsa shi, don haka zare mai yawa ya dace ne kawai da sadarwa mai ƙananan ƙarfin fiber optic.

Rarraba ma'aunin refractive na zare mai yawa galibi yana da parabolic, ma'ana yana da ma'aunin refractive mai daraja. Diamita na tsakiya shine kimanin 50 µm.
2. Zaren yanayi ɗaya

Idan girman siffar zare (musamman diamita na tsakiya) zai iya kasancewa kusa da tsawon haske, misali, diamita na tsakiya d1 yana cikin kewayon 5-10 µm, zare yana ba da damar yanayi ɗaya kawai (yanayin asali HE11) ya yaɗu a ciki, kuma sauran yanayin mafi girma ana yanke su; irin waɗannan zare ana kiran su zare na yanayi ɗaya.

Tunda yana da yanayin yaɗawa ɗaya kawai kuma yana guje wa matsalar yaɗuwar yanayi, fiber mai yanayin guda ɗaya yana da faɗi sosai kuma ya dace musamman don sadarwa mai ƙarfin gaske ta fiber optic. Saboda haka, don cimma yaɗuwar yanayi ɗaya, dole ne sigogin zare su cika wasu sharuɗɗa. Ana ƙididdige shi ta amfani da dabarar cewa ga zare mai NA=0.12, don cimma yaɗuwar yanayi ɗaya sama da λ=1.3 µm, radius na tsakiyar zare dole ne ya zama ≤4.2 µm, wato, diamita na tsakiya d1≤8.4 µm.

Tunda girman tsakiyar zare mai amfani da na'urar hangen nesa guda ɗaya ƙanana ne, ana buƙatar tsauraran buƙatu kan tsarin kera shi.