Kuyankhulana kwa fiber, monga chimodzi mwa mizati yayikulu ya kulankhulana kwamakono, kumagwira ntchito yofunika kwambiri pamagulu amakono a telecommunication.
Kachitidwe ka chitukuko cha optical fiber communication itha kuyembekezera kuchokera kuzinthu zotsatirazi.
1.Kuti muzindikire kuchuluka kwa chidziwitso ndi kufalitsa mtunda wautali, ulusi wamtundu umodzi wokhala ndi kutayika kochepa komanso kufalikira kochepa uyenera kugwiritsidwa ntchito. Pakali pano, G.652 ochiritsira single-mode kuwala CHIKWANGWANI chimagwiritsidwa ntchito kulankhulana maukonde kuwala chingwe mizere. Ngakhale ulusi uwu umakhala ndi kutayika kochepa kwa 1.55 μm, uli ndi mtengo wobalalika kwambiri pafupifupi 18 ps / (nm.km). Zimanenedwa kuti pamene fiber yamtundu umodzi imagwiritsidwa ntchito pamtunda wa 1.55 μm, ntchito yopatsirana si yabwino.
Ngati zero-dispersion wavelength imasinthidwa kuchoka ku 1.31 μm kupita ku 1.55 μm, imatchedwa dispersion-shifted fiber (DSF), koma pamene fiber iyi ndi erbium-doped fiber amplifier (EDFA) imagwiritsidwa ntchito mu wavelength division multiplexing system (WDM) , idzakhala Chifukwa cha kusagwirizana kwa fiber, kusakanikirana kwa mafunde anayi kumachitika, zomwe zimalepheretsa kugwiritsa ntchito WDM mwachizolowezi, zomwe zikutanthauza kuti kufalikira kwa zero sikuli bwino kwa WDM.
Kuti ukadaulo wolumikizirana ndi fiber fiber ugwiritsidwe bwino pa dongosolo la WDM, kufalikira kwa fiber kuyenera kuchepetsedwa, koma sikuloledwa kukhala zero. Chifukwa chake, ulusi watsopano wamtundu umodzi wopangidwa umatchedwa non-zero dispersion fiber (NZDF), womwe umachokera ku 1.54 ~ Mtengo wobalalika mumtundu wa 1.56μm ukhoza kusungidwa pa 1.0 ~ 4.0ps / (nm.km), womwe umapewa malo obalalitsa ziro, koma amasunga mtengo wobalalika pang'ono.
Zitsanzo zambiri zanenedwa poyera pogwiritsa ntchito NZDF's EDFA / WDM transmission system.
Zipangizo za 2.Photonic zomwe zimagwiritsidwa ntchito mu optical fiber communication systems zapanganso kwambiri m'zaka zaposachedwapa. Pofuna kukwaniritsa zosowa zamakina a WDM, zida zamtundu wa multi-wavelength light source (MLS) zapangidwa zaka zaposachedwa. Imakonza machubu angapo a laser motsatizana ndikupanga hybrid integrated Optical component ndi star coupler.
Pakulandira mapeto a njira yolumikizirana ndi fiber optical, photodetector yake ndi preamplifier imapangidwa makamaka potengera kuyankha kothamanga kwambiri kapena kwamagulu ambiri. PIN photodiodes imatha kukwaniritsa zofunikira pambuyo pa kukonza. Kwa ma photodetectors a Broadband omwe amagwiritsidwa ntchito mu bandi ya kutalika kwa 1.55μm, chubu chachitsulo cha semiconductor-metal photodetection chubu (MSM) chapangidwa zaka zaposachedwa. Oyendayenda yoweyula anagawira photodetector. Malinga ndi malipoti, MSM iyi imatha kuzindikira 78dB ya 3dB frequency bandwidth kwa mafunde a kuwala kwa 1.55μm.
FET's preamplifier ikhoza kusinthidwa ndi high electron mobility transistor (HEMT). Akuti 1.55μm optoelectronic receiver pogwiritsa ntchito chowunikira cha MSM ndi HEMT pre-amplified optoelectronic integration (OEIC) ili ndi ma frequency band a 38GHz ndipo ikuyembekezeka kufika 60GHz.
3. Dongosolo la PDH la point-to-point transmission mu optical fiber communication system silinathe kugwirizanitsa ndi chitukuko cha ma telecommunication networks. Chifukwa chake, kukulitsa kulumikizana kwa fiber optical kupita ku network kwakhala njira yosapeŵeka.
SDH ndi njira yatsopano yolumikizira netiweki yokhala ndi zoyambira pamaneti. Ndi makina azidziwitso athunthu omwe amaphatikiza ma multiplexing, kutumiza mizere ndikusintha ntchito ndipo ali ndi mphamvu zowongolera maukonde. Panopa akugwiritsidwa ntchito kwambiri.