Hauv 20 xyoo dhau los, kev txhim kho ntawm kev sib txuas lus fiber ntau tau tshaj tib neeg' lub tswv yim, thiab kev sib txuas lus kho qhov muag kuj tau dhau los ua lub hauv paus ntawm kev sib txuas lus niaj hnub no. Kev sib txuas lus fiber ntau optical tau dhau los ntawm ntau theem ntawm kev txhim kho. Los ntawm PDH system nyob rau hauv lub lig 1970s, lub SDH system nyob rau hauv nruab nrab-90s, thiab lub tsis ntev los no surge DWDM system, mus rau lub neej yav tom ntej ntse optical network technology, lub optical fiber kev sib txuas lus system nws tus kheej yog sai tau hloov kho.
Wavelength division multiplexing thev naus laus zis tau tshwm sim txij li qhov tshwm sim ntawm kev sib txuas lus fiber ntau. Thaum xyoo 1980s thiab thaum ntxov 1990s, Dr. Dingyi Li (TYLee) ntawm AT& T Tswb Labs tau tawm tswv yim rau kev siv tshuab ntawm wavelength division multiplexing (DWDM), ob-wavelength WDM (1310/1550nm) Lub kaw lus tau siv. Hauv Asmeskas AT& T network hauv xyoo 1980s ntawm tus nqi ntawm 2 × 1.7Gb / s. Tab sis nyob rau hauv nruab nrab-1990s, WDM system kev loj hlob ceev tsis ceev, lub ntsiab yog vim li cas:
(1) TDM (lub sij hawm faib multiplexing) technology kev loj hlob, 155Mb/s-622Mb/s-2.5Gb/s TDM tshuab yog kuj yooj yim. Raws li kev txheeb cais, qis dua 2.5Gb / s system (xws li 2.5Gb / s system), txhua zaus lub kaw lus tau hloov kho, tus nqi xa mus ib me ntsis poob li ntawm 30%. Vim li no, hauv kev hloov kho tshiab dhau los, tib neeg tau xav txog thiab tau txais TDM thev naus laus zis.
(2) Wavelength division multiplexing devices tseem tsis tau paub meej. Wavelength division multiplexers / demultiplexers thiab optical amplifiers tsuas yog pib ua lag luam thaum xyoo 1990s.
Cov laj thawj tseem ceeb rau kev txhim kho sai ntawm DWDM yog:
(1) TDM10Gb/s tab tom ntsib kev sib tw ntawm cov khoom siv hluav taws xob, thiab kev siv TDM tau nce mus txog qhov txwv ntawm silicon thiab gallium arsenic technology. TDM tsis muaj peev xwm siv tau ntau npaum li cas, thiab tus nqi ntawm cov khoom siv kis tau tus mob kuj siab heev.
(2) Lub siab dispersion ntawm G.652 fiber ntau 1550nm qhov rais uas tau muab tso tseg tau txwv kev sib kis ntawm TDM10Gb/s system, thiab lub zog ntawm fiber chromatic dispersion thiab polarization hom dispersion yog nce. Tib neeg tab tom hloov lawv txoj kev txaus siab los ntawm hluav taws xob multiplexing mus rau optical multiplexing, uas yog, siv ntau yam multiplexing txoj hauv kev kho qhov muag los txhim kho kev sib kis tau zoo thiab nce multiplexing tus nqi. WDM thev naus laus zis tam sim no yog qhov yooj yim tshaj plaws los ua lag luam. Optical multiplexing tshuab.
(3) Kev loj hlob sai ntawm cov khoom siv optoelectronic. Xyoo 1985, University of Southampton hauv tebchaws United Kingdom thawj zaug tsim cov khoom siv hluav taws xob-doped fiber ntau. Xyoo 1990, Pirelli tau tsim thawj lub lag luam fiber ntau amplifier (EDFA). Kev loj hlob thiab kev lag luam ntawm EDFA ua rau WDM thev naus laus zis sib kis tau ntev.
Los ntawm kev pom kev thiab kev lag luam, DWDM thev naus laus zis tam sim no yog qhov kev lag luam tshaj plaws thiab muaj peev xwm ntawm kev nthuav dav.
