Txog xyoo 1960, tus kws tshawb fawb Asmeskas Maiman tau tsim thawj lub laser hauv ntiaj teb, uas muab lub teeb pom kev zoo rau kev sib txuas lus kho qhov muag. Tshaj li 20 xyoo tom ntej no, tib neeg tau ua tiav hauv kev tshaj tawm xov xwm kho qhov muag thiab thaum kawg ua kom tsis tshua muaj cov khoom siv kho qhov muag, uas tau tsim 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.
Fiber optic kis tau tus mob muaj ntau yam zoo:
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 dav dua qhov zaus band uas tuaj yeem xa cov teeb liab. Hauv VHF zaus band, tus cab kuj zaus yog 48.5MHz txog 300Mhz. Lub bandwidth yog hais txog 250MHz, thiab tsuas yog 27 teev ntawm TV thiab kaum ob ntawm FM tshaj tawm tuaj yeem kis tau. Qhov zaus ntawm lub teeb pom kev nce mus txog 100000 GHz, uas yog ntau tshaj li ib lab lub sij hawm siab dua VHF zaus band. Txawm hais tias fiber ntau optic fibers muaj qhov poob sib txawv ntawm lub teeb ntawm ntau zaus, uas cuam tshuam rau bandwidth, bandwidth hauv thaj tsam poob qis tshaj kuj tuaj yeem ncav cuag 30000 GHz. Lub bandwidth ntawm ib lub teeb pom kev tsuas yog suav rau ib feem me me ntawm nws (qhov zaus band ntawm multimode fibers yog li ob peb puas megahertz, thiab ib hom fibers zoo tuaj yeem ncav cuag tshaj 10GHz). Siv cov kev sib txuas lus kho qhov muag zoo tshaj plaws, 2000 optical carriers tuaj yeem npaj nyob rau hauv 30000 GHz ntau yam rau wavelength division multiplexing, uas tuaj yeem ua rau ntau lab ntawm cov channel.
Kev poob qis
Nyob rau hauv ib lub kaw lus tsim los ntawm coaxial cables, qhov zoo tshaj plaws cable tau poob ntau dua 40dB ib kilometer thaum xa 800MHz signals. Hauv qhov sib piv, qhov poob ntawm optical fiber ntau me dua. Thaum xa tawm 1.31um lub teeb, qhov poob ib km tsawg dua 0.35dB. Yog tias kis tau 1.55um lub teeb, qhov poob ib km me dua, txog li 0.2dB. Qhov no yog 100 lab lub sij hawm tsawg dua lub zog poob ntawm coaxial cables, tso cai rau lawv xa mus rau qhov ntev ntev.
Tsis tas li ntawd, muaj ob yam ntxwv ntawm fiber ntau optic kis tau tus mob,
Ib qho yog kom muaj qhov poob zoo ib yam thoob plaws txhua lub xov tooj cua hauv TV, thiab tsis tas yuav ua kom paub qhov sib npaug rau kev sib npaug zoo li hauv cov kab hluav taws xob;
Qhov thib ob, nws qhov poob tsis tshua hloov nrog qhov kub thiab txias, yog li tsis tas yuav txhawj xeeb txog kev hloov pauv hauv cov kab tseem ceeb los ntawm kev hloov pauv ntawm qhov kub thiab txias.
Lub teeb
Vim hais tias cov fiber ntau optical nyias nyias, txoj kab uas hla ntawm ib leeg-hom optical fiber core feem ntau yog 4um rau 10um, thiab sab nraud tsuas yog 125um. Nrog rau qhov sib ntxiv ntawm cov txheej txheem dej tsis sib haum, kev txhawb zog, thiab cov ntaub qhwv, txoj kab uas hla ntawm cov kab hluav taws xob kho qhov muag muaj li ntawm 4-48 fibers optical tsawg dua 13 hli, uas yog me dua li txoj kab uas hla ntawm tus qauv coaxial cable ntawm 47 hli. Tsis tas li ntawd, cov khoom siv kho qhov muag yog ua los ntawm cov iav fiber ntau thiab muaj qhov sib nqus tshwj xeeb, ua rau nws muaj lub ntsej muag me me thiab lub teeb yuag, ua rau kev teeb tsa yooj yim heev.
Muaj peev xwm tiv thaiv kev cuam tshuam
Vim hais tias cov khoom tseem ceeb ntawm optical fiber yog quartz, uas tsuas yog xa tawm lub teeb thiab tsis yog conductive, thiab tsis cuam tshuam los ntawm electromagnetic teb, cov teeb liab optical kis tau rau hauv nws tsis cuam tshuam los ntawm electromagnetic teb. Yog li, optical fiber kis tau tus mob muaj zog tiv thaiv electromagnetic cuam tshuam thiab muaj kev cuam tshuam. Vim li no, cov teeb liab kis tau nyob rau hauv optical fibers tsis yooj yim eavesdropped, yog li yooj yim tsis pub lwm tus paub.
Siab ncaj ncees
Vim hais tias fiber ntau optic kis tau tus mob feem ntau tsis xav tau relay amplification, nws yuav tsis qhia tshiab nonlinear distortion vim amplification. Ntev npaum li qhov linearity ntawm lub laser yog zoo, nws muaj peev xwm kis tau TV signals nrog siab fidelity. Cov kev sim ua tau pom tau tias qhov zoo tshaj plaws amplitude modulation fiber optic system muaj cov cab kuj sib xyaw ua ke triple tuav piv ntawm ntau dua 70dB rau C / CTB, thiab qhov ntsuas qhov ntsuas nruab nrab ntawm ntau dua 60dB rau cM, uas yog siab dua li qhov ntsuas qhov tsis sib xws ntawm cov kab hluav taws xob dav dav. tshuab.
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 cuab yeej siv ntau dua, qhov ntau dua qhov ua tsis tiav. Vim tias cov tshuab fiber ntau muaj cov khoom siv me me (tsis zoo li cov kab hluav taws xob uas xav tau ntau lub tshuab hluav taws xob), lawv qhov kev ntseeg siab yog siab heev. Tsis tas li ntawd, cov khoom siv fiber ntau muaj lub neej ntev, nrog lub sijhawm ua haujlwm tsis raug ntawm 500000 txog 750000 teev. Ntawm lawv, lub laser nyob rau hauv lub optical transmitter muaj qhov luv tshaj lifespan, nrog ib tug tsawg kawg nkaus lifespan ntawm tshaj 100000 teev. Yog li ntawd, kev ua haujlwm ntawm kev tsim qauv zoo, raug teeb tsa thiab debugged fiber ntau optic system yog txhim khu kev qha.
Cov nqi pheej yig dua
Ib tug neeg tau thov tsab cai tshiab Moore, tseem hu ua Optical Law. Txoj cai lij choj hais tias bandwidth ntawm fiber optic kis tau tus mob ntawm cov ntaub ntawv ob zaug txhua rau lub hlis, thaum tus nqi txo los ntawm ib zaug. Txoj kev loj hlob ntawm kev sib txuas lus kho qhov muag tshuab tau tso lub hauv paus zoo heev rau kev txhim kho Internet broadband technology. Qhov no tshem tawm qhov teeb meem kawg rau cov kab hluav taws xob loj hauv xov tooj cua los txais yuav kev sib kis ntawm fiber ntau optic. Vim muaj ntau qhov chaw ntawm cov ntaub ntawv (quartz) siv nyob rau hauv zus tau tej cov optical fibers, tus nqi yuav ntxiv txo nrog rau kev nce qib ntawm technology; Cov khoom siv tooj liab uas xav tau rau cov cables raug txwv, thiab cov nqi yuav nce ntxiv. Obviously, yav tom ntej, optical fiber ntau kis tau tus mob yuav ua kom zoo dua thiab ua qhov tseem ceeb tshaj plaws kis tau tus mob txhais tau tias tsim kom muaj cable TV tes hauj lwm nyob rau hauv lub xeev thiab txawm lub teb chaws.
