Ndi mitundu yanji ya ma SDM air-division multiplexing fibers?

Pakafukufuku ndi chitukuko cha umisiri watsopano wa optical fiber, SDM space division multiplexing yakopa chidwi chachikulu. Pali njira ziwiri zazikulu zogwiritsira ntchito SDM mu optical fibers: core division multiplexing (CDM), momwe kupatsirana kumachitika kudzera pakatikati pa multi-core optical fiber. Kapena Mode Division Multiplexing (MDM), yomwe imafalikira kudzera munjira zofalitsa zamitundu yochepa kapena yamitundu yambiri.

Chingwe cha Core Division Multiplexing (CDM) chimakhala chokhazikika pakugwiritsa ntchito njira ziwiri zazikulu.

Yoyamba imachokera pakugwiritsa ntchito ma single-core fiber bundles (ma riboni a ulusi), momwe ulusi wamtundu umodzi umalumikizidwa pamodzi kuti apange mitolo ya ulusi kapena nthiti zomwe zimatha kupereka maulalo mazana ambiri ofanana.

Njira yachiwiri idakhazikika pakutumiza deta pachinthu chimodzi (mode imodzi pachimake) chophatikizidwa mu ulusi womwewo, mwachitsanzo mu MCF multicore fiber. Chigawo chilichonse chimatengedwa ngati njira imodzi yokha.

Fiber ya MDM (Module Division Multiplexing) imatanthawuza kutumiza kwa deta pamitundu yosiyanasiyana ya ulusi wa kuwala, iliyonse yomwe ingaganizidwe ngati njira yosiyana.

Mitundu iwiri yodziwika bwino ya MDM ndi fiber multimode (MMF) ndi fractional mode fiber (FMF). Kusiyana kwakukulu pakati pa ziwirizi ndi chiwerengero cha modes (njira zomwe zilipo). Popeza ma MMF amatha kuthandizira mitundu yambiri (makumi amitundu), intermodal crosstalk ndi differential mode group delay (DMGD) imakhala yofunika.

Palinso photonic crystal fiber (PCF) yomwe tinganene kuti ndi yamtunduwu. Zimachokera ku zinthu za photonic crystals, zomwe zimagwirizanitsa kuwala kupyolera muzitsulo za bandgap ndikuzitumiza pogwiritsa ntchito mabowo a mpweya mu gawo lake.PCF imapangidwa makamaka ndi zinthu monga SiO2, As2S3, etc., ndi mabowo a mpweya amayambitsidwa m'dera lozungulira pachimake kuti asinthe kusiyana kwa chiwerengero cha refractive pakati pa pachimake ndi chovala.

Ulusi wa CDM ukhoza kufotokozedwa ngati kuwonjezereka kwazitsulo zamtundu umodzi wamtundu umodzi wonyamula zidziwitso, zomwe zimayikidwa muzitsulo zomwezo (multi-core fiber MCF kapena single-core fiber bundle) .