DWDM System Principple
DWDM thev naus laus zis siv cov bandwidth thiab tsis tshua muaj cov yam ntxwv ntawm ib hom fiber ntau, siv ntau lub wavelengths raws li cov neeg nqa khoom, thiab tso cai rau txhua tus neeg nqa khoom xa mus ib txhij hauv fiber ntau.
Piv nrog rau cov kab ke dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav dav, nkoj nkoj nkoj nkoj, suav nrog Tuam Tshoj Tuam Tshoj los ntawm Tuam Tshoj los ntawm Tuam Tshoj. tshwj xeeb tshaj yog nws tuaj yeem txuas ncaj qha Nkag mus rau ntau yam kev lag luam ua rau nws daim ntawv thov kev cia siab heev.
Hauv cov kab ke sib txuas lus analog, txhawm rau ua kom siv tag nrho cov peev txheej bandwidth ntawm lub cable thiab txhim kho lub peev xwm kis tau tus mob, txoj kev faib ntau zaus ntau zaus yog siv. Ntawd yog, cov teeb liab ntawm ntau txoj kev sib txuas ib txhij nyob rau hauv tib lub cable, thiab qhov kawg tau txais siv lub band-pass lim los lim tawm cov teeb liab ntawm txhua lub channel raws li cov neeg nqa khoom sib txawv.
Ib yam li ntawd, optical zaus division multiplexing txoj kev kuj yuav siv tau nyob rau hauv lub optical fiber kev sib txuas lus system los txhim kho lub peev xwm kis tau tus mob ntawm lub system. Qhov tseeb, xws li multiplexing txoj kev no zoo heev nyob rau hauv optical fiber kev sib txuas lus systems. Sib txawv ntawm qhov sib faib ntau zaus hauv kev sib txuas lus analog, hauv kev sib txuas lus fiber ntau, lub teeb nthwv dej yog siv los ua lub teeb liab, thiab qhov poob qis ntawm cov khoom siv kho qhov muag tau muab faib ua ntau yam raws li qhov zaus (los yog wavelength) ntawm txhua channel lub teeb yoj. raws, thiaj li paub txog cov multiplexed kis tau tus mob ntawm ntau yam optical signals nyob rau hauv ib tug optical fiber.
Txij li qee cov khoom siv kho qhov muag (xws li cov ntxaij lim dej uas muaj qhov nqaim heev, cov teeb pom kev sib txuas, thiab lwm yam) tseem tsis tau paub tab, nws yog ib qho nyuaj heev kom paub txog qhov sib faib ntau zaus ntawm kev sib faib (coherent optical kev sib txuas lus technology) nrog cov khoom siv kho qhov muag tuab heev. Raws li cov cuab yeej tam sim no, kev faib ntau zaus ntawm kev sib cais ntawm cov kab hluav taws xob sib cais tau pom tau. Cov neeg feem ntau hu ua multiplexing ntawm optical channels nrog qhov sib txawv loj (txawm tias nyob rau ntawm qhov sib txawv ntawm cov fibers optical fibers) optical wavelength division multiplexing (WDM), thiab ces hu rau DWDM nrog me me channel sib nrug nyob rau hauv tib lub qhov rais raws li ntom wavelength division multiplexing (DWDM). ). Nrog rau kev nce qib ntawm kev tshawb fawb thiab thev naus laus zis, cov thev naus laus zis niaj hnub no tau ua tiav kev sib tw nrog lub sijhawm wavelength ntawm nanometers, thiab txawm tias multiplexing nrog lub caij nyoog wavelength ntawm ob peb feem kaum ntawm nanometer, tab sis cov kev xav tau ntawm cov cuab yeej muaj zog dua, yog li qhov 1270nm Lub wavelength band ntawm 1610nm rau 20nm yog hu ua Coarse Wavelength Division Multiplexing (CWDM).
Schematic daim duab ntawm qhov muaj pes tsawg leeg thiab spectrum ntawm DWDM system. Lub optical transmitter ntawm qhov kawg xa tawm cov teeb liab kho qhov muag nrog cov wavelengths sib txawv tab sis nrog qee qhov tseeb thiab kev ruaj ntseg, uas yog multiplexed los ntawm optical wavelength multiplexer thiab xa mus rau erbium-doped fiber ntau lub zog amplifier (erbium-doped fiber ntau amplifier feem ntau yog siv rau compensate rau nws yuav txo tau lub hwj chim poob thiab txhim kho lub zog kis tau tus mob ntawm optical teeb liab), thiab ces xa cov amplified multi-txoj kev kho qhov muag teeb liab mus rau hauv lub optical fiber rau kis tau tus mob. Hauv nruab nrab, nws tuaj yeem txiav txim siab seb puas muaj cov kab hluav taws xob kho qhov muag lossis tsis yog raws li qhov xwm txheej, thiab nws mus txog qhov kawg tau txais los ntawm kev kho qhov muag preamplifier (tsuas yog siv los txhim kho qhov tau txais rhiab heev txhawm rau txhawm rau txuas qhov sib kis) Tom qab amplification , nws raug xa mus rau qhov kho qhov muag wavelength demultiplexer kom decompose tus thawj optical signals.