Silica iav tsis sib npaug pob tshab ntawm txhua lub wavelength. Attenuation thiab chromatic dispersion sib txawv nyob rau hauv ze ntawm -infrared spectrum, thiab lub wavelength ranges uas poob mus txog qhov ua tau minima hu ua optical transmission windows.
Lub physics qab qhov no yog to taub zoo. Rayleigh scattering poob li 1/λ⁴, lub ntsiab lus ntev wavelengths tawg tsawg dua. Infrared molecular absorption, ntawm qhov tod tes, nce siab tshaj li ntawm 1600 nm. Lub attenuation yam tsawg kawg yog zaum qhov twg ob lub tshuab hla - ze 1550 nm. Qhov kev hla ntawd yog vim li cas C-band nyob ntawm qhov chaw spectral nws ua. Cais, qhov seem ntawm OH⁻ ion nqus cov ncov nyob ze 1383 nm keeb kwm tsim ib qho chaw tuag hauv cov spectrum, uas yog vim li cas O-band thiab S-band tsis sib txuas.
Xya ITU-T Standardized Bands
| Band | Wavelength Range | Lub npe |
|---|---|---|
| 850nm ua | 810-890 nm | 850nm wb |
| O | 1260-1360 nm | Original Band |
| E | 1360–1460 nm | Extended Band |
| S | 1460–1530 nm | Luv Wavelength Band |
| C | 1530–1565 nm | Pauv Band |
| L | 1565–1625 nm | Ntev Wavelength Band |
| U | 1625–1675 nm | Ultra-Long Wavelength Band |
Plaub ntawm cov no nqa cov khoom lag luam ntau: 850 nm, O-band, C-band, thiab L-band. Qhov peb seem ua haujlwm nqaim dua.
C-Band (1530–1565 nm)
C-band yog lub hauv paus ntawm kev sib txuas kho qhov muag niaj hnub. Nws zaum hauv qab ntawm silica attenuation nkhaus, nyob ib ncig ntawm 0.19–0.20 dB/km, thiab nws qhov rais nce mus raws li Erbium-Doped Fiber Amplifiers. Qhov kev sib raug zoo no yog qhov sib txawv ntawm physics - emission spectrum ntawm erbium ions hauv silica iav tshwm sim los sib tshooj nrog cov fiber ntau poob yam tsawg kawg nkaus - tab sis tag nrho ntev - kev thauj mus los hauv kev lag luam nyob ntawm nws.
| Parameter | Tus nqi |
|---|---|
| Fiber hom | G.652, G.654 ib leeg-mos |
| Attenuation | ~ 0.20 dB/km |
| Amplification | EDFA |
| DWDM channel muaj peev xwm | Mus txog 96 raws ntawm 50 GHz qhov sib nrug |
Kev xa tawm ib txwm muaj xws li DWDM ntev-haul thiab ultra-ntev- lub hauv paus caj dab sib txuas, submarine cable systems, 100G / 200G / 400G / 800G coherent transport, thiab data center interconnect over 80+ km spans. Ib khub fiber ntau hauv C-band DWDM tuaj yeem nqa 40-96 raws ntawm 100G lossis siab dua - aggregate peev xwm hauv kaum tawm terabits ib ob.
Spectral efficiency ntawm ntau C-band txoj kev yog tam sim no mus rau Shannon txwv raws li coherent DSP thawb mus rau 800G thiab 1.6T ib lub wavelength. Thaum tus lej tsis ua haujlwm raws li koj qhov kev pom zoo, cov lus teb siv tau ua kom muaj peev xwm L-band muaj peev xwm ntawm tib lub fiber ntau es tsis txhob sim nyem ntau cov khoom tawm ntawm txhua qhov channel.
O-Band (1260–1360 nm)
Lub O-band yog thawj lub qhov rais siv kev lag luam rau ib zaug - hom fiber ntau thiab txuas ntxiv ua tus thawj coj nruab nrab - kev sib txuas. Cov cuab yeej tseem ceeb: chromatic dispersion yog zero ntawm 1310 nm nyob rau hauv tus qauv G.652 fiber, lub ntsiab lus uas cov khoom dispersion thiab waveguide dispersion tshem tawm. Optical pulses tuav lawv cov duab nyob deb yam tsis tau them nyiaj, uas txhais tau hais tias cov transceivers tuaj yeem tso siab tau yooj yim ncaj qha -nrhiav architectures - pheej yig dua thiab qis zog dua li coherent C-band modules.
| Parameter | Tus nqi |
|---|---|
| Fiber hom | G.652 ib leeg -hom |
| Attenuation | ~ 0.35 dB/km |
| Chromatic dispersion | Zero ntawm 1310 nm |
| Hom ncav cuag | 10-40 km tsis muaj amplification |
Kev siv ntau: 10G LR, 25G LR, 100G LR4 modules; metro Ethernet; enterprise WAN thiab tsaus fiber point-rau-point; PON sab sauv (1310 nm, subscriber rau OLT); BiDi thiab CWDM transceivers.
Kev lag luam - tawm yog ncaj nraim. O-band attenuation ntawm 0.35 dB/km khiav li 75% siab dua C-band, thiab EDFAs tsis ua hauj lwm ntawm cov wavelengths. Tshaj li 40-80 km koj xav tau C-band. Nyob rau hauv metro deb, O-band yeej ntawm dispersion simplicity thiab transceiver nqi. Semiconductor optical amplifiers thiab O-Band coherent transceivers nyob rau hauv txoj kev loj hlob thiab tuaj yeem thawb qhov siv tau mus txog ntxiv, tab sis kev xa tawm ntim yuav tsis tshwm sim.
850nm wb
Hauv cov tsev thiab cov chaw zov me nyuam, 850 nm band ua ke nrog VCSEL cov chaw thiab multimode fiber ua haujlwm feem ntau ntawm luv luv - mus txog qhov txuas. Attenuation siab - nyob ib ncig ntawm 2.5–3.5 dB/km - tab sis thaum koj qhov ntev tshaj plaws cable khiav yog 300 meters, tus lej ntawd tsis cuam tshuam.
| Parameter | Tus nqi |
|---|---|
| Fiber hom | OM3, OM4, OM5 multimode |
| Attenuation | ~ 3 dB/km |
| Hom ncav cuag | Mus txog 400 m ntawm OM4 ntawm 100G |
VCSEL-raws li optics nqi tsawg dua DFB- laser modules, uas yog tag nrho cov ntsiab lus. Server-rau-hloov, sab saum toj- ntawm- khib, lub hauv paus tsev kawm ntawv, 10G/25G/40G/100G SR - tag nrho 850 nm thaj chaw.
Cov qauv tsim nyog taug qab: cov chaw zov me nyuam cov ntaub ntawv hyperscale tau nce ntxiv ib qho - hom fiber ntau hauv kev tsim tshiab los txhawb 200G thiab 400G rau ib - txoj kab. Qhov no maj mam noj rau hauv 850 nm qhov sib koom ntawm qhov siab kawg. Tab sis rau lub hauv paus loj ntawm cov khoom siv fiber ntau thiab rau tus nqi- cov kev lag luam tseem ceeb, 850 nm band yuav tsis mus qhov twg sai sai no.
L{0}}Band (1565–1625 nm)
L-band ua haujlwm raws li C-band's overflow. Nws muaj qhov thib ob - qis qis qis tshaj hauv tus qauv ib zaug - hom fiber ntau ntawm kwv yees li 0.22 dB / km thiab tuaj yeem nthuav dav nrog L-band EDFAs.
| Parameter | Tus nqi |
|---|---|
| Fiber hom | G.652 ib leeg -hom |
| Attenuation | ~ 0.22 dB/km |
| Amplification | L-band EDFA |
Ntxiv L-band EDFAs thiab C+L mux/demux ntawm cov chaw amplifier uas twb muaj lawm kwv yees li ob npaug ntawm qhov siv taufiber ntau bandwidthntawm infrastructure twb nyob rau hauv av, ntawm ib feem ntawm ib tug tshiab tsim tus nqi. Qhov no yog thawj lub peev xwm tus neeg tsav tsheb rub thaum C-band puv.
Kev xa tawm C + L tam sim no yog tus qauv ntawm cov txheej txheem submarine loj thiab muaj ntau zuj zus nyob rau hauv siab - tsheb thauj mus los hauv av. Kev sib xyaw ua ke C + L spectrum tau hloov los ntawm qhov zoo - mus rau - muaj peev xwm npaj lub hauv paus rau kev ncua ntev -haul infrastructure, tshwj xeeb tshaj yog raws li ib tug - wavelength tus nqi nce mus rau 800G.
The Secondary Bands
S{0}}Band (1460–1530 nm)
Niaj hnub no S-band cov kev lag luam tseem ceeb siv yog PON: GPON thiab XG-PON siv 1490 nm rau cov tsheb khiav qis los ntawm OLT rau cov neeg siv khoom. Ntxiv mus, S-band yog lub hom phiaj tshawb fawb rau tom ntej - tiam S + C + L wideband DWDM. Thulium-doped fiber amplifiers thiab Raman amplification yog cov neeg sib tw tau txais kev daws teeb meem, tab sis tsis yog ze rau qhov sib piv C/L-band EDFA tus nqi lossis kev ntseeg siab ntawm kev tsim khoom. Lab ua qauv qhia muaj nyob; loj -scale coj mus muag S-band DWDM tsis.
E-Band (1360–1460 nm)
Lub OH⁻ dej ncov ze 1383 nm keeb kwm ua rau cov qhab no siv tsis tau. G.652.D xoom dej ncov fiber ntau tshem tawm qhov nqus, thiab E-band attenuation ntawm ZWP fiber ntau poob qis dua O-band qib. Qhov teeb meem yog ntsia hauv paus: feem ntau fiber ntau hauv av thoob ntiaj teb yog legacy G.652.A lossis G.652.B nrog cov dej ncov tsis zoo. Kev lag luam E-band transceivers thiab amplifiers tseem tsis tshua muaj. Qhov tseeb tiag, E-band tsuas yog qhov tseem ceeb hauv greenfield tsim ntawm ZWP fiber ntau qhov twg txhua qhov muaj CWDM qhov xav tau.
U-Band (1625–1675 nm)
U-band tsis muaj cov ntaub ntawv khiav. Nws ib leeg muaj nuj nqi yog tawm - ntawm -band fiber saib xyuas. OTDR cov cuab yeej ntawm U-band wavelengths txhaj tshuaj pulses mus rau hauv fiber ntau, ntsuas qhov kev xav, kev poob qis, cov khoom sib txuas zoo, thiab tawg yam tsis muaj kev cuam tshuam cov kev pabcuam nquag ntawm lwm cov qhab.
Xaiv Txoj Cai Hloov Qhov rai
| Kev xav tau | Pom zoo Band | Yog vim li cas |
|---|---|---|
| Txuas hauv qab 400 m, multimode fiber ntau | 850nm ua | Tus nqi qis tshaj nrog VCSEL optics; ncav cuag txaus |
| Txuas 1–40 km, ib leeg - hom, tsis muaj kev nthuav dav | O-band (1310 nm) | Zero -zero dispersion; yooj yim transceiver tsim |
| FTTH nqes hav (PON / GPON) | S{0}}band (1490 nm) | PON tus qauv rau OLT-rau- tus neeg siv khoom qis |
| Txuas tshaj 40 km, lossis DWDM xav tau | C{0}}band (1550 nm) | Kev poob qis tshaj; EDFA tau tshaj; siab tshaj channel ceev |
| C-band ntawm lub peev xwm, xav tau ntau cov channel ntawm fiber ntau uas twb muaj lawm | L-pab | Nyob ze - siv tau ob npaug ntawm cov spectrum nrog kev hloov pauv me me |
| Fiber saib xyuas kev noj qab haus huv tsis muaj kev cuam tshuam kev tsheb | U-pab | Tawm - ntawm -band OTDR kev kuaj mob |
| Ntau wavelengths, metro, tsis muaj amplification | CWDM hla O + E + S + C + L | 20nm sib nrug; mus txog 18 channels; tus nqi qis dua DWDM |
Cov Kev Txiav Txim Tseem Ceeb
Nruab Fiber Hom
Multimode fiber ntau (OM3/OM4) confines siab - ceev txuas mus rau 850 nm. Txoj Cai G.652.A/B ib leeg -mode txwv tsis pub E-band vim qhov dej siab tshaj. Cov fiber ntau twb nyob hauv av yog thawj qhov txwv - txhua yam ua raws li nws.
Amplification Requirement
EDFAs ua haujlwm hauv C thiab L bands nkaus xwb. Cov kev sib txuas uas yuav tsum tau kho qhov muag pom kev zoo - feem ntau tshaj li 80 km - yuav tsum siv ib qho ntawm ob pawg no. Kev nthuav dav O-band tshaj 40 km txhais tau hais tias yog hluav taws xob rov tsim dua lossis siab - lub zog tsis muaj zog sib txuas sib txuas, ob qho tib si ntxiv tus nqi.
Channel suav thiab Multiplexing Strategy
CWDM txhawb nqa txog li 18 channels nrog 20 nm sib nrug, tsis muaj kev nthuav dav, thiab qis dua rau ib tus nqi -channel. DWDM packs 40–96+ channels rau hauv C-band ib leeg (ntau dua nrog L-band), yuav tsum muaj EDFAs, thiab xa cov peev txheej ntau dua. Feem ntau metro thiab kev sib txuas ua lag luam tau txais txiaj ntsig zoo los ntawm CWDM. Cov pob txha, submarine, thiab loj - nplai DCI xav tau DWDM. Lub crossover point yog kwv yees li 8-10 channels los yog amplified spans tshaj 80 km.
Tus nqi Transceiver thiab Fais Fab Nyiaj Txiag
850nm VCSEL optics yog qhov pheej yig tshaj. O-band DFB-raws li modules (LR, LR4) zaum hauv nruab nrab. C-band coherent modules nqa tus nqi siab tshaj plaws thiab lub zog kos. Tsis muaj qhov txiaj ntsig zoo rau kev siv cov khoom siv kho qhov muag sib txuas ntawm 10 km metro txuas uas O-band LR module ua haujlwm yam tsis muaj teeb meem.
Yuav ua li cas WDM Siv Kev Sib Txuas Windows
Wavelength Division Multiplexingmuab cov wavelengths sib txawv rau cov ntaub ntawv ywj pheej thiab xa lawv ib txhij dhau ib fiber ntau. Cov qhov rais kis tau tus mob txhais tag nrhobandwidth ntawm fiber ntaumuaj rau qhov multiplexing no.
CWDM
20 nm channel sib nrug ntawm O, E, S, C, thiab L bands. Mus txog 18 channels. Tsis xav tau amplification tshaj li ib txwm metro nrug. Uncooled lasers khaws cov nqi qis. Siv nyob rau hauv metro networks, sub-80 km data center interconnect, thiab enterprise maub fiber txuas.
DWDM
100 GHz lossis 50 GHz channel sib nrug hauv C-band, xaiv tau txuas ntxiv mus rau L-band. 40 channels ntawm 100 GHz lossis 96 ntawm 50 GHz, txhua tus nqa 100G lossis ntau dua. EDFAs xav tau rau kev ncua ntev. Muab tso rau ntawm ntev-haul qaum qaum, submarine cables, thiab siab{12}}bandwidth fiber ntaukev sib txuas.
Qhov kev xaiv ntawm CWDM thiab DWDM los ntawm kev muaj peev xwm piv rau tus nqi. CWDM yog pheej yig dua rau ib channel tab sis sab saum toj ntawm 18 channels tsis muaj kev nthuav dav. DWDM raug nqi ntau dua tab sis ntsuas rau kaum tawm terabits ntawm ib khub fiber ntau.
FAQ
Q: Kuv yuav ua li cas xam cov peev nyiaj txuas los txiav txim seb kuv qhov fiber ntau xav tau kev nthuav dav li cas?
A: Cov peev nyiaj txuas ntxiv ntxiv tag nrho cov kev poob ntawm kev xa xov thiab txais: fiber ntau attenuation ib kilometer multiplied by span length, plus splice losses (feem ntau 0.05–0.1 dB txhua), connector poob (ib ncig 0.3–0.5 dB ib khub niam txiv), thiab ib qho margin reserved rau kev laus thiab kho dua tshiab). Sib piv tag nrho rau koj lub transceiver lub optical zog pob nyiaj siv - qhov sib txawv ntawm kev xa hluav taws xob thiab cov neeg txais rhiab heev. Yog tias qhov poob tag nrho ntau dua li cov peev nyiaj siv hluav taws xob, koj xav tau kev nthuav dav (EDFA hauv C / L-band) lossis hluav taws xob rov tsim dua tshiab.
Q: Puas muaj hnub nyoog fiber ntau degrade kev sib kis tau zoo hla ntau pawg?
A: Yog. Ntau xyoo ntawm kev pab cuam, fiber ntau attenuation tuaj yeem nce vim hydrogen ingress, microbending los ntawm cable kev nyuaj siab, thiab cumulative raug rau ya raws. Cov teebmeem no yog wavelength-dependent - wavelengths ntev dua nyob rau hauv L-band thiab U-band zoo li yuav rhiab heev rau microbending poob dua li luv wavelengths. Tsis tas li ntawd, cov khoom siv fiber ntau tau teeb tsa ua ntej G.652.D cov qauv yuav pom OH⁻ dej ncov zuj zus zuj zus mus rau lub sijhawm yog tias muaj hydrogen nkag mus. Rau cov tes hauj lwm uas tau npaj nrog 15-20 xyoo lifecycle, nws tsim nyog rau qhov kev laus ntawm 0.02-0.05 dB / km thaum tsim cov peev nyiaj txuas.
Q: Kuv puas tuaj yeem khiav C-band thiab O-band teeb liab ib txhij ntawm tib lub fiber ntau?
A: Yog. Txij li thaum C-band (1530–1565 nm) thiab O-band (1260–1360 nm) nyob tsis yog- sib tshooj wavelength ranges, lawv tuaj yeem koom ua ke ntawm ib qho fiber ntau siv dav WDM couplers lossis band splitters. Ib qho xwm txheej raug ua haujlwm DWDM ntev- tsheb thauj mus los hauv C-band thaum nqa 10G lossis 25G LR kev sib txuas hauv zos hauv O-band ntawm tib lub fiber ntau. Qhov tseem ceeb yuav tsum tau yog band kom raug- lim ntawm txhua qhov kawg kom tiv thaiv kev sib tham. Txoj hauv kev no ua rau kev siv fiber ntau yam tsis tas siv cov kab txuas ntxiv.
Q: Yuav ua li cas ambient kub cuam tshuam rau fiber ntau kis tau tus mob nyob rau hauv txawv bands?
A: Kub hloov ua rau me me hloov hauv fiber ntau attenuation thiab chromatic dispersion. Rau attenuation, cov nyhuv yog me me hauv C-band thiab O-band nyob rau hauv ib txwm ua haujlwm (–40℃rau +70 degree), feem ntau tsawg dua 0.01 dB/km variation. Kev hloov pauv hloov pauv tuaj yeem muaj teeb meem rau siab -kev sib txuas ceev ceev khiav ntawm 400G lossis siab dua - qhov xoom-dispersion wavelength ntawm G.652 fiber ntau drifts me ntsis nrog kub, uas tej zaum yuav xav tau kev hloov kho DSP. Sab nraum zoov cable nroj tsuag nrog dav kub viav vias yuav tsum suav rau qhov no nyob rau hauv cov kab ke kab ke, tshwj xeeb tshaj yog nyob rau ntev amplified spans uas me me ib -km hloov pauv.
Q: Dab tsi yog qhov ua tau zoo tshaj plaws ntawm wavelengths kuv tuaj yeem khiav ntawm ib qho fiber ntau hnub no?
A: Hauv kev sib txuas ntau lawm, C + L band DWDM system nrog 50 GHz channel spacing txhawb nqa kwv yees li 160-192 wavelengths ntawm ib qho fiber ntau. Ntawm 400G ib channel, qhov no txhais tau ntau dua 60 Tbps aggregate peev ib fiber ntau. . Rau CWDM kev xa tawm, qhov ua tau zoo tshaj plaws yog 18 raws thoob plaws txhua pawg nrog 20 nm sib nrug. Qhov tseeb siv tau yog nyob ntawm koj hom fiber ntau tau teeb tsa - legacy fiber nrog cov dej ncov txo CWDM mus rau thaj tsam 8–10 raws los ntawm kev tshem tawm E-band slots.
