A kokarin neman karin karfin aiki da kuma tsawon nisan watsawa a tsarin sadarwa na zamani, hayaniya, a matsayin wani muhimmin takaitaccen yanayi, koyaushe tana takaita ci gaban aiki.
A cikin wani tsari na yau da kullunEDFATsarin amplifier na fiber mai amfani da erbium, kowane zangon watsawa na gani yana samar da kusan 0.1dB na hayaniyar fitar da iska mai sauri (ASE), wanda ya samo asali ne daga yanayin bazuwar hulɗar haske/electron a lokacin aikin ƙara girma.
Wannan nau'in hayaniyar tana bayyana a matsayin jitter na matakin picosecond a cikin yankin lokaci. Dangane da hasashen samfurin jitter, a ƙarƙashin yanayin ma'aunin watsawa na 30ps/(nm · km), jitter yana ƙaruwa da 12ps lokacin watsawa 1000km. A cikin yankin mita, yana haifar da raguwa a cikin rabon siginar gani-zuwa-amo (OSNR), wanda ke haifar da asarar ji na 3.2dB (@ BER=1e-9) a cikin tsarin NRZ na 40Gbps.
Babban ƙalubalen ya fito ne daga haɗakar tasirin fiber marasa layi da kuma watsawa - ma'aunin watsawa na zare mai yanayi ɗaya na yau da kullun (G.652) a cikin taga 1550nm shine 17ps/(nm · km), tare da canjin yanayin da ba na layi ba wanda canjin yanayin yanayin kai (SPM) ke haifarwa. Lokacin da ƙarfin shigarwa ya wuce 6dBm, tasirin SPM zai ɓata yanayin bugun jini sosai.
A cikin tsarin PDM-16QAM na 960Gbps da aka nuna a cikin hoton da ke sama, buɗewar ido bayan watsawa ta kilomita 200 shine kashi 82% na ƙimar farko, kuma ana kiyaye ma'aunin Q a 14dB (wanda ya yi daidai da BER ≈ 3e-5); Lokacin da aka tsawaita nisan zuwa kilomita 400, haɗin tasirin daidaitawar lokaci-lokaci (XPM) da haɗa raƙuman ruwa huɗu (FWM) yana sa matakin buɗe ido ya ragu sosai zuwa kashi 63%, kuma ƙimar kuskuren tsarin ya wuce iyaka mai tsauri ta gyaran kuskuren FEC na 10 ^ -12.
Ya kamata a lura cewa tasirin mitar girgizar laser mai daidaitawa kai tsaye (DML) zai tabarbare - ƙimar sigar alpha (factor enhancement factor) na laser DFB na yau da kullun yana cikin kewayon 3-6, kuma canjin mitar sa nan take zai iya kaiwa ± 2.5GHz (daidai da sigar chirp C=2.5GHz/mA) a yanayin canjin wutar lantarki na 1mA, wanda ke haifar da faɗaɗa bugun jini na 38% (tarin watsawa ta tarin D · L=1360ps/nm) bayan watsawa ta hanyar zaren G.652 na 80km.
Tashar sadarwa a tsarin rarrabawa na tsawon zango (WDM) ta ƙunshi cikas masu zurfi. Idan aka ɗauki tazara ta hanyar tashar 50GHz a matsayin misali, ƙarfin tsangwama da haɗawar raƙuman ruwa huɗu (FWM) ke haifarwa yana da tsawon Leff na kusan kilomita 22 a cikin zare na gani na yau da kullun.
Takaitaccen bayani game da tashar sadarwa a tsarin rarrabawa na tsawon zango (WDM) ya ƙunshi cikas masu zurfi. Idan aka ɗauki tazara ta hanyar tashar 50GHz a matsayin misali, tsawon ƙarfin tsangwama da aka samar ta hanyar haɗa raƙuman ruwa huɗu (FWM) shine Leff = 22km (wanda ya yi daidai da ƙimar rage ƙarfin fiber α = 0.22 dB/km).
Idan aka ƙara ƙarfin shigarwa zuwa +15dBm, matakin magana tsakanin tashoshi masu maƙwabtaka yana ƙaruwa da 7dB (idan aka kwatanta da tushen -30dB), wanda hakan ke tilasta tsarin ƙara yawan aikin gyara kuskuren gaba (FEC) daga 7% zuwa 20%. Tasirin canja wurin wutar lantarki da Raman warwatsewa (SRS) ke haifarwa yana haifar da asarar kusan 0.02dB a kowace kilomita a cikin dogayen tashoshi masu tsayi, wanda ke haifar da raguwar wutar lantarki har zuwa 3.5dB a cikin tsarin C+L (1530-1625nm). Ana buƙatar diyya ta gangara ta ainihin lokaci ta hanyar daidaita ƙarfin gain (DGE).
Ana iya ƙididdige iyakar aikin tsarin na waɗannan tasirin jiki da aka haɗa ta hanyar samfurin nisan bandwidth (B · L): B · L na tsarin daidaitawa na NRZ na yau da kullun a cikin fiber G.655 (fiber mai ramawa) yana da kusan 18000 (Gb/s) · km, yayin da tare da daidaitawar PDM-QPSK da fasahar ganowa mai jituwa, ana iya inganta wannan alamar zuwa 280000 (Gb/s) · km (@ SD-FEC gain 9.5dB).
Fiber mai girman 7-core x 3-mode space division multiplexing fiber (SDM) ya sami damar watsawa na 15.6Pb/s · km (ikon fiber guda ɗaya na nisan watsawa na 1.53Pb/sx na 10.2km) a cikin yanayin dakin gwaje-gwaje ta hanyar rashin ƙarfin haɗin gwiwa tsakanin tsakiya da tsakiya (<-40dB/km).
Domin kusantar iyakar Shannon, tsarin zamani yana buƙatar haɗakar ɗaukar tsarin siffanta yiwuwar (PS-256QAM, cimma nasarar siffanta 0.8dB), daidaita hanyar sadarwa ta jijiyoyi (ingancin diyya na NL ya inganta da kashi 37%), da kuma fasahar Raman amplification (DRA, samun daidaiton gangara ± 0.5dB) don ƙara yawan Q factor na watsawa na 400G PDM-64QAM mai ɗaukar kaya guda ɗaya da 2dB (daga 12dB zuwa 14dB), da kuma sassauta juriyar OSNR zuwa 17.5dB/0.1nm (@ BER=2e-2).
Lokacin Saƙo: Yuni-12-2025