WDM yog cov txheej txheem sib kis uas siv ib qho kev xaib fiber ntau rau tib lub sij hawm xa mus rau ntau tus neeg nqa khoom ntawm cov kab hluav taws xob sib txawv ntawm cov xov hluav taws xob sib txuas. Cov kis poob hauv cov kab nrig mas nws txawv nrog nthwv dej ntawm lub teeb. Txhawm rau kom txo qhov poob kom ntau li ntau tau thiab xyuas kom meej cov kis xa mus, peb yuav tsum nrhiav qhov haum tshaj plaws rau kev xa mus. Tom qab siv sijhawm ntev los tshawb thiab sim, lub teeb nyob rau hauv qhov kawg wavelength ntawm 1260nm ~ 1625nm muaj lub teeb liab qis kawg nkaus thiab poob los ntawm kev tawg thiab yog qhov tsim nyog rau kev sib kis hauv fiber ntau.
Lub nthwv dej ntawm lub ntsej muag hluav taws xob tej zaum yuav siv tau muab faib ua ob peb pawg, thiab txhua txoj hlua siv los ua cov ywj siab channel kom xa cov cim ntawm lub teeb nrig ua ntej ntawm lub yoj yoj. ITU-T faib cov khoom zaus ntawm hom ib hom kho qhov muag fiber ntau saum 1260nm rau hauv O, E, S, C, L thiab U pawg.
O band yog dab tsi?
O-band yog tus thawj 1260-1360 nm band. O pawg yog thawj pawg sib txawv nyob hauv keeb kwm siv rau kev sib txuas lus kho qhov muag, muaj qhov teeb liab tsawg kawg nkaus (vim yog tawg).
E-band yog dab tsi?
E band (ncua ntev ntev: 1360-1460 nm) yog qhov tsawg tshaj plaws ntawm cov kab sib txuas. E band feem ntau siv raws li kev txuas ntxiv ntawm O band, tab sis nws tsis tshua siv, feem ntau vim tias ntau cov xov tooj uas twb muaj lawm qhia tau zoo siab ntawm E band thiab cov txheej txheem tsim yog cov zog siv zog, yog li lawv siv nyob rau hauv kev sib txuas lus kho qhov muag yog txwv.
S band yog dab tsi?
Optical fiber poob hauv S-band (luv-wavelength Band: 1460-1530 nm) qis dua li cov uas nyob hauv O-band, thiab S-band siv ntau PON (passive optical network) cov tshuab.
C-band yog dab tsi?
C Band (Cov Pa Kab Ke) ib puag ncig los ntawm 1530 nm txog 1565 nm thiab sawv cev rau ntawm Conventional Band. Cov hluav taws xob fiber ntau pom qhov poob qis tshaj hauv C-band thiab muaj qhov kom muaj txiaj ntsig zoo nyob rau hauv kev sib kis ntev ntev. Lawv feem ntau siv rau hauv nroog loj, qhov chaw nyob deb, ultra-ntev nrug thiab undersea kho qhov muag kis tshuab ua ke nrog WDM siv EDFA thev naus laus zis. C-band tau dhau los ua qhov tseem ceeb dua thaum kev xa mus deb. Nrog rau qhov tshwm sim ntawm DWDM (ntom ntom ntom ntaws sib faib ua ke sib txuam), uas tso cai rau ntau lub teeb liab los qhia cov fiber ntau, kev siv C-band tau nthuav dav.
Dab tsi yog L band?
Qhov L-band (ntev-wavelength Band: 1565-1625 nm) yog qhov thib ob qis dua ntawm Wavelength Band thiab feem ntau yog siv thaum C-band tsis txaus rau qhov kev xav tau bandwidth. Nrog rau kev nthuav dav ntawm B-doped fiber amplifiers (EDFA), DWDM cov tshuab tau txuas ntxiv mus rau L-band thiab tau pib siv los nthuav cov peev txheej hauv av DWDM optical network. Tam sim no nws tau qhia rau submarine cable cov tswv kom ua qhov qub - nthuav dav tag nrho cov peev txheej ntawm submarine cable.
Vim tias cov kis attenuation poob ntawm ob kis Windows, C band thiab L band, yog qhov tsawg kawg, teeb liab teeb rau hauv DWDM system feem ntau raug xaiv hauv C band thiab L band. Ntxiv rau O-band rau L-band, tseem muaj ob lwm pab pawg, yog 850 nm band thiab U band (ultra-ntev band: 1625-1675 nm). Lub 850 nm band yog lub ntsiab yoj ntawm cov kab ke sib txuas lus fiber ntau, ua ke nrog VCSEL (ntsug kab noj hniav nto emitting laser). U-band tsuas yog siv rau kev saib xyuas network.
WDM thev naus laus zis tuaj yeem muab faib ua WDM, CWDM thiab DWDM raws cov qauv sib txawv ntawm yoj yoj. Qhov ntau ntawm lub yoj yoj teem los ntawm ITU rau CWDM (ITU-T G. 694.2) yog 1271 txog 1611 nm, tab sis nyob rau hauv daim ntawv thov, xav txog qhov sib kis ntawm qhov ntau ntawm cov qhab ntawm 1270 txog 1470nm, cov kab ntau ntawm 1470 txog 1610nm feem ntau siv. DWDM cov chaw tso tawm kom pom kev zoo dua, siv C band (1530 nm-1565 nm) thiab L band (1570nm-1610nm) kis tau rau Windows. General WDM feem ntau siv 1310 thiab 1550nm wavelength.
Nrog rau kev loj hlob ntawm FTTH daim ntawv thov, cov tshuab C-band feem ntau siv thiab L-band hauv cov khoos phis tawm fiber ntau yuav ua si ntau dua thiab tseem ceeb hauv kev xa xov kho qhov muag.
