Kev sib kis zoo
Txog xyoo 1960, tus kws tshawb fawb Asmeskas Maiman tau tsim lub ntiaj teb' thawj lub laser, uas muab lub teeb pom kev zoo rau kev sib txuas lus kho qhov muag. Tom qab ntau tshaj li ob xyoo lawm, tib neeg tau ua kev tshawb fawb ntawm optical transmission media thiab thaum kawg ua cov khoom siv kho qhov muag qis, yog li tso lub hauv paus ntawm kev sib txuas lus kho qhov muag. Txij thaum ntawd los, kev sib txuas lus kho qhov muag tau nkag mus rau theem ntawm kev loj hlob sai.
Optical fiber ntau kis tau tus mob muaj ntau yam zoo:
Ntau zaus bandwidth
Qhov dav ntawm cov zaus band sawv cev rau qhov loj ntawm lub peev xwm kis tau tus mob. Qhov siab dua ntawm cov cab kuj, qhov bandwidth ntau dua ntawm cov teeb liab uas tuaj yeem kis tau. Hauv VHF zaus band, tus cab kuj zaus yog 48.5MHz ~ 300Mhz. Nrog lub bandwidth ntawm 250MHz, nws tsuas yog xa tau 27 TV teeb thiab kaum tawm FM tshaj tawm. Qhov zaus ntawm lub teeb pom kev mus txog 100,000 GHz, uas yog ntau tshaj li ib lab lub sij hawm siab dua VHF zaus band. Txawm hais tias cov khoom siv kho qhov muag muaj qhov sib txawv ntawm qhov sib txawv ntawm lub teeb, qhov bandwidth cuam tshuam, tab sis qhov bandwidth hauv thaj tsam poob qis tshaj kuj tuaj yeem ncav cuag 30,000 GHz. Tam sim no, lub bandwidth ntawm ib lub teeb pom kev tsuas yog nyob ib feem me me ntawm nws (qhov ntau zaus ntawm ntau hom fiber ntau yog li ob peb puas MHz, thiab ib hom fiber ntau zoo tuaj yeem ncav cuag ntau dua 10 GHz). Kev siv cov kev sib txuas lus kho qhov muag tau zoo tuaj yeem npaj 2,000 teeb nyob rau hauv thaj tsam ntawm 30,000 GHz. Carrier, wavelength division multiplexing, tuaj yeem ua rau ntau lab channels.
Kev poob qis
Nyob rau hauv ib lub kaw lus tsim los ntawm coaxial cables, qhov zoo tshaj plaws cable muaj ib tug poob ntawm ntau tshaj 40dB ib kilometer thaum xa 800MHz signals. Nyob rau hauv sib piv, qhov poob ntawm optical fiber ntau me me, kis tau tus mob ntawm 1.31um ntawm lub teeb, qhov poob ib kilometer yog qis dua 0.35dB, yog hais tias tus kis tau tus mob ntawm 1.55um ntawm lub teeb, qhov poob ib kilometer me me, mus txog 0.2dB los yog tsawg. Qhov no yog 100 lab lub sij hawm me dua lub zog poob ntawm ib coaxial cable, ua rau nws muaj peev xwm mus kis tau tus mob ntawm ib tug ntev npaum li cas. Tsis tas li ntawd, optical fiber ntau kis tsis tau muaj ob yam ntxwv. Ib qho yog tias nws muaj qhov poob zoo ib yam hauv txhua qhov cable TV raws, thiab tsis tas yuav ua kom paub qhov sib npaug rau kev sib npaug zoo li lub cev cable; Lwm qhov yog tias nws qhov poob tsis tshua hloov nrog qhov kub thiab txias, yog li koj tsis tas yuav txhawj txog nws. Kev hloov pauv ntawm qhov kub thiab txias ua rau lub hauv paus hloov pauv.
Lub teeb nyhav
Vim hais tias cov fiber ntau optical nyias nyias, txoj kab uas hla ntawm ib hom fiber ntau core hlau feem ntau yog 4um ~ 10um, thiab sab nraud tsuas yog 125um. Nrog cov txheej txheem dej tsis muaj dej, txhawb nqa cov tav, sheath, thiab lwm yam, txoj kab uas hla ntawm ib qho khoom siv kho qhov muag muaj li ntawm 4 txog 48 fibers optical tsawg dua 13 hli. Nws yog ntau me dua li tus qauv coaxial cable nrog txoj kab uas hla ntawm 47mm. Tsis tas li ntawd, cov khoom siv kho qhov muag yog cov iav fiber ntau nrog lub ntiajteb txawj nqus me me, uas ua rau nws muaj cov yam ntxwv ntawm txoj kab uas hla me me thiab lub teeb yuag, thiab nws yooj yim heev rau nruab.
Muaj peev xwm tiv thaiv kev cuam tshuam
Vim hais tias lub hauv paus ntawm optical fiber yog quartz, nws tsuas yog kis lub teeb, tsis ua hluav taws xob, thiab tsis cuam tshuam los ntawm electromagnetic teb. Cov teeb liab optical kis tau nyob rau hauv nws tsis cuam tshuam los ntawm electromagnetic teb. Yog li ntawd, optical fiber kis tau tus mob muaj zog tiv thaiv electromagnetic cuam tshuam thiab muaj kev cuam tshuam. Precisely vim hais tias ntawm no, lub teeb liab kis tau nyob rau hauv lub optical fiber yog tsis yooj yim rau eavesdropped, uas yog conducive rau tsis pub leejtwg paub.
Siab ncaj ncees
Vim hais tias optical fiber ntau kis tsis tau relay amplification, nws yuav tsis qhia tshiab nonlinear distortions vim amplification. Ntev npaum li qhov linearity ntawm lub laser yog zoo, lub teeb liab TV yuav kis tau nrog siab fidelity. Qhov kev sim tiag tiag qhia tau hais tias cov cab kuj sib xyaw ua ke triple tuav piv C / CTB ntawm qhov zoo AM fiber ntau yog ntau dua 70dB, thiab qhov ntsuas qhov nruab nrab cM kuj yog ntau dua 60dB, uas yog ntau dua li qhov ntsuas qhov tsis sib xws ntawm cov kab hluav taws xob dav dav. qhov system.
Txhim khu kev ua haujlwm zoo
Peb paub tias qhov kev ntseeg siab ntawm ib qho system muaj feem xyuam nrog cov xov tooj ntawm cov khoom siv uas tsim cov kab ke. Cov khoom siv ntau dua, qhov ntau dua qhov ua tsis tiav. Vim tias tus naj npawb ntawm cov cuab yeej muaj nyob rau hauv qhov kho qhov muag fiber ntau yog me me (tsis zoo li lub kaw lus cable uas yuav tsum muaj ntau lub amplifiers), qhov kev ntseeg siab yog siab heev. Tsis tas li ntawd, lub neej ntawm cov khoom siv fiber ntau siv tau ntev heev, thiab lub sijhawm ua haujlwm tsis muaj teeb meem yog 500,000 txog 750,000 teev. Ntawm lawv, lub neej luv tshaj plaws yog lub laser hauv optical transmitter, thiab lub neej qis tshaj yog ntau tshaj 100,000 teev. Yog li ntawd, kev ua haujlwm ntawm kev tsim qauv zoo, raug teeb tsa thiab debugged optical fiber ntau yog qhov txhim khu kev qha.
Tus nqi tseem poob qis
Tam sim no, qee cov neeg tau thov tsab cai tshiab Moore' txoj cai, kuj hu ua txoj cai kho qhov muag (Optical Law). Txoj cai lij choj hais tias bandwidth ntawm optical fiber kis tau tus mob ntawm cov ntaub ntawv ob zaug txhua txhua 6 lub hlis, thaum tus nqi yog ob npaug. Txoj kev loj hlob ntawm kev sib txuas lus kho qhov muag tau tsim lub hauv paus zoo heev rau kev txhim kho Internet broadband technology. Qhov no tau tshem tawm qhov teeb meem kawg rau cov kab hluav taws xob loj hauv xov tooj cua los txais yuav txoj kev xa xov fiber ntau. Txij li thaum lub hauv paus ntawm cov khoom siv (quartz) rau optical fiber ntau ntau, nrog rau kev nce qib ntawm kev siv tshuab, tus nqi yuav raug txo ntxiv; thaum cov khoom siv tooj liab uas yuav tsum tau siv rau cable yog txwv, tus nqi yuav siab dua thiab siab dua. Obviously, optical fiber ntau kis tau tus mob yuav muaj qhov zoo tshaj plaws nyob rau hauv lub neej yav tom ntej, thiab nws yuav dhau los ua txoj kev sib kis tseem ceeb tshaj plaws rau kev tsim cov cable TV hauv tag nrho lub xeev thiab txawm tias tag nrho lub tebchaws.
Lub hauv paus ntsiab lus
Optical fiber ntau yog tsim los ntawm ob txheej iav nrog sib txawv refractive indexes. Cov txheej sab hauv yog ib qho khoom siv kho qhov muag nrog lub cheeb ntawm ob peb micrometers mus rau ntau kaum micrometers, thiab txoj kab uas hla ntawm txheej txheej yog 0.1 txog 0.2 hli. Feem ntau, qhov refractive index ntawm lub iav core yog 1% loj dua li ntawm cov iav txheej. Raws li lub hauv paus ntsiab lus ntawm lub teeb refraction thiab tag nrho cov kev xav, thaum lub kaum sab xis ntawm lub teeb hits lub interface ntawm lub hauv paus ntsiab lus thiab txheej txheej yog ntau dua li lub kaum sab xis tseem ceeb rau tag nrho cov kev xav, lub teeb tsis tuaj yeem dhau los ntawm lub interface thiab muaj kev cuam tshuam tag nrho. .
Fiber ntau attenuation
Cov yam tseem ceeb uas ua rau muaj fiber ntau attenuation yog: intrinsic, khoov, nyem, impurities, unevenness thiab pob tw, thiab lwm yam.
Qhov tseeb
Nws yog qhov poob ntawm qhov muag fiber ntau, suav nrog: Rayleigh tawg, qhov nqus nqus, thiab lwm yam.
khoov
Thaum kho qhov muag fiber ntau yog khoov, ib feem ntawm lub teeb nyob rau hauv lub optical fiber yuav ploj vim tawg, ua rau poob.
extrusion
Poob tshwm sim los ntawm kev khoov me ntsis thaum lub optical fiber yog nyem.
impurity
Cov impurities nyob rau hauv optical fiber absorbs thiab tawg lub teeb propagating nyob rau hauv lub optical fiber, ua rau poob.
Tsis sib xws
Poob tshwm sim los ntawm qhov tsis sib xws refractive index ntawm cov khoom siv fiber ntau.
Docking
Qhov poob los ntawm fiber ntau pob tw, xws li: sib txawv axis (ib hom fiber ntau coaxiality yuav tsum muaj tsawg dua 0.8μm), lub ntsej muag kawg tsis yog perpendicular rau axis, lub ntsej muag kawg tsis tiaj tus, lub taub qab taub hau yog tsis phim, thiab qhov zoo ntawm splicing tsis zoo.
Artificial attenuation
Hauv kev ua haujlwm tiag tiag, qee zaum yuav tsum ua cov khoom siv kho qhov muag fiber ntau attenuation, xws li optical fiber attenuators siv hauv kev sib txuas lus kho qhov muag kom debug optical zog kev ua tau zoo, debug optical fiber ntau ntsuas ntsuas, thiab kho qhov muag fiber ntau attenuation.
txoj kev tsim khoom
Tam sim no, cov fiber ntau optical siv hauv kev sib txuas lus feem ntau yog silica optical fiber. Lub npe tshuaj ntawm quartz yog silicon dioxide (SiO2), uas muaj tib lub ntsiab lus tseem ceeb xws li cov xuab zeb peb siv los tsim tsev. Txawm li cas los xij, optical fibers ua los ntawm cov khoom siv quartz zoo tib yam tsis tuaj yeem siv rau kev sib txuas lus. Kev sib txuas lus kho qhov muag fiber ntau yuav tsum yog cov khoom siv siab heev; Txawm li cas los xij, ntxiv ib qho me me ntawm dopant rau hauv cov khoom tseem ceeb tuaj yeem ua rau qhov refractive index ntawm cov tub ntxhais thiab cladding me ntsis txawv, uas yog qhov zoo rau kev sib txuas lus.
Muaj ntau txoj hauv kev rau kev tsim kho qhov muag fiber ntau preform los ntawm VAD txoj kev. Tam sim no, muaj ntau yam: hauv-tube CVD (cov tshuaj vapor deposition) txoj kev, hauv-qhib CVD txoj kev, PCVD (plasma tshuaj vapor deposition) txoj kev thiab VAD (axial vapor deposition) txoj kev. Tab sis tsis muaj teeb meem dab tsi yog siv, lub preform yuav tsum tau ua nyob rau hauv high kub ua ntej, thiab ces rhuab thiab softened nyob rau hauv ib tug kub-kub rauv, kos rau hauv ib tug filament, thiab ces coated thiab molded los ua ib tug optical fiber core hlau. Kev tsim cov fibers kho qhov muag xav kom txhua tus txheej txheem yuav tsum ua kom muaj tseeb thiab tswj tau los ntawm lub computer. Nyob rau hauv tus txheej txheem ntawm kev tsim fiber ntau optical, peb yuav tsum xyuam xim rau:
Optical fiber preform ua los ntawm VAD txoj kev
① Lub purity ntawm optical fiber raw khoom yuav tsum siab heev.
② Nws yog ib qho tsim nyog los tiv thaiv impurity paug thiab huab cua npuas los ntawm kev nkag mus rau cov fiber ntau optical.
③ Txhawm rau kom tswj tau qhov kev faib tawm ntawm qhov ntsuas qhov cuam tshuam;
④ Tswj qhov loj ntawm cov khoom siv kho qhov muag;
⑤ Txo qhov caws pliav puas tsuaj ntawm qhov chaw ntawm cov khoom siv kho qhov muag thiab txhim kho lub zog ntawm cov khoom siv kho qhov muag.
Tube stick method
Ntxig lub puab iav pas nrig rau hauv lub khob iav sab nrauv (kom ze li sai tau), yaj thiab kos cov hlau;
Ob chav crucible txoj kev
Nyob rau hauv ob concentric platinum crucibles, muab lub puab core thiab txheej iav frit rau hauv lub puab thiab sab crucibles feem;
Molecular filling method
Lub microporous silica iav pas nrig yog immersed nyob rau hauv cov tshuaj additives nrog siab refractive index kom tau tus ntoo khaub lig-sectional qauv ntawm qhov yuav tsum tau refractive index faib, thiab tom qab ntawd lub lag luam yog ua. Cov txheej txheem yog qhov nyuaj dua. Hauv kev sib txuas lus kho qhov muag fiber ntau, cov txheej txheem sab hauv thiab sab nrauv vapor deposition tuaj yeem siv los xyuas kom meej tias cov fibers optical uas tsis tshua muaj qhov muag tsis pom tuaj yeem tsim tau.
Qhov chaw fusion
Muab cov khoom siv fiber ntau nyob rau hauv microgravity ib puag ncig ntawm qhov chaw rub nws, thiab koj tuaj yeem tau txais lub teeb pom kev zoo ultra-ntev zoo tshaj plaws fiber ntau uas tsis muaj nyob hauv lub ntiaj teb.
Fiber classification
Raws li cov txheej txheem kev faib tawm ntawm cov qauv sib txawv ntawm cov qauv kho qhov muag fiber ntau, tib lub fiber ntau optical yuav muaj cov npe sib txawv.
Classified los ntawm cov khoom siv fiber ntau
Raws li cov khoom siv ntawm cov khoom siv kho qhov muag, cov hom fiber ntau tuaj yeem muab faib ua quartz optical fiber thiab tag nrho cov yas optical fiber.
Silica fiber feem ntau yog hais txog cov khoom siv kho qhov muag uas tsim los ntawm doped silica core thiab doped silica cladding. Cov fiber ntau no tau poob qis heev thiab nruab nrab dispersion. Tam sim no, feem ntau ntawm cov fibers kho qhov muag rau kev sib txuas lus yog quartz optical fibers.
Txhua-yas kho qhov muag fiber ntau yog ib hom tshiab ntawm optical fiber rau kev sib txuas lus, uas tseem nyob rau hauv txoj kev loj hlob thiab sim theem. Txhua-yas fiber ntau muaj cov yam ntxwv ntawm kev poob loj, cov tub ntxhais tuab (100-600μm inch), cov lej loj aperture (NA) (feem ntau yog 0.3-0.5, uas tuaj yeem ua ke nrog cov teeb pom kev zoo nrog cov teeb pom kev loj dua) thiab cov nqi tsim khoom tsawg. Tam sim no, tag nrho cov yas kho qhov muag fiber ntau yog tsim rau kev siv luv luv, xws li kev sib txuas hauv computer hauv tsev thiab kev sib txuas lus hauv nkoj.
Kev faib tawm los ntawm fiber ntau profile refractive index faib
Raws li qhov sib txawv refractive index faib ntawm fiber ntau profile, hom fibers yuav muab faib ua kauj ruam-type fibers thiab graded-type fibers.
Classified los ntawm hom kis tau tus mob
Raws li tus naj npawb ntawm optical fiber kis tau tus mob hom, hom optical fibers yuav muab faib ua multi-mode optical fibers thiab ib hom optical fibers.
Ib hom fiber ntau yog fiber ntau uas tuaj yeem kis tau ib hom nkaus xwb. Ib hom fiber ntau tsuas yog kis tau tus qauv tseem ceeb (tsawg-txiav hom), tsis muaj qhov sib txawv ntawm kev ncua sijhawm, thiab muaj qhov bandwidth loj dua li ntau hom fiber ntau, uas yog qhov tseem ceeb heev rau kev sib kis ceev. Hom teb kab ntawm ib hom fiber ntau tsuas yog ob peb microns (μm), thiab nws cov bandwidth feem ntau yog ib lossis ob qhov kev txiav txim siab ntau dua li ntawm cov qib multimode fiber ntau. Yog li ntawd, nws yog qhov tsim nyog rau kev muaj peev xwm loj, kev sib txuas lus ntev.
Kev faib tawm raws li cov qauv thoob ntiaj teb (kev faib tawm raws li ITU-T cov lus pom zoo)
Txhawm rau ua kom cov fiber ntau kho qhov muag muaj kev sib koom ua ke thoob ntiaj teb, International Telecommunication Union (ITU-T) tau tsim ib qho kev sib koom ua ke ntawm cov khoom siv kho qhov muag (G standard). Raws li ITU-T cov lus pom zoo ntawm optical fibers, hom optical fibers tuaj yeem muab faib ua:
G.651 fiber ntau (50/125μm multimode graded index fiber)
G.652 fiber ntau (non-dispersion hloov fiber ntau)
G.653 fiber ntau (dispersion hloov fiber ntau DSF)
G.654 fiber ntau (txiav tawm wavelength ua haujlwm fiber ntau)
G.655 fiber ntau (non-zero dispersion hloov fiber ntau).
Txhawm rau ua kom tau raws li qhov xav tau ntawm kev txhim kho cov thev naus laus zis tshiab, tam sim no G.652 fiber ntau tau muab faib ua peb pawg G.652A, G.652B, thiab G.652C, thiab G.655 fiber ntau tau muab faib ntxiv rau hauv G.655A thiab G.655B. Cov qeb.
Raws li IEC tus qauv kev faib tawm, IEC tus qauv faib cov hom fiber ntau rau hauv
Hom A multimode fiber ntau:
A1a Multimode fiber ntau (50/125μm hom multimode fiber)
A1b multimode fiber ntau (62.5 / 125μm hom multimode fiber)
A1d multimode fiber ntau (100/140μm hom multimode fiber)
Class B ib hom fiber ntau:
B1.1 sib raug rau G652 fiber ntau, thiab B1.3 fiber ntau ntxiv kom sib haum rau G652C fiber ntau
B1.2 sib raug rau G654 fiber ntau
B2 fiber sib raug rau G.653 fiber ntau
B4 fiber sib raug rau G.655 fiber ntau
