1.optical eriri isi Ọdịdị
1) Core: elu refractive index, eji na-ebunye ọkụ;
2) Cladding: obere refractive index, na-akpụ a ngụkọta echiche ọnọdụ na isi;
3) oyi akwa mkpuchi: na-echebe eriri anya.
2.Single-mode na multi-mode
Naanị otu ụdị ọkụ nwere ike ibunye.Ya mere, ya inter-mode mgbasa bụ obere na adabara ime nkwurịta okwu, ma e nwekwara ihe dispersion na waveguide dispersion.N'ụzọ dị otú a, eriri otu mode nwere ihe dị elu chọrọ maka obosara na nkwụsi ike nke ìhè ọkụ, ya bụ, obosara obosara ga-adị warara na nkwụsi ike ka mma.Otu ụdị eriri nwere efu mkpokọta mgbasa.
Nwere ike ibunye ọtụtụ ụdị ọkụ.Otú ọ dị, mgbasa ozi n'etiti ọnọdụ ya buru ibu, nke na-egbochi oge nke na-ebufe akara dijitalụ, ọ ga-adịkwa njọ site n'ịbawanye anya.Ogologo nnyefe eriri ọtụtụ ụdị dị mkpụmkpụ, n'ozuzu naanị kilomita ole na ole.
Ngwá ọrụ otu ụdị nwere ike na-agba ọsọ na eriri otu mode ma ọ bụ eriri multimode, ebe akụrụngwa na-ejedebe na-agba ọsọ na eriri multi mode.