Nrog txoj kev loj hlob sai ntawm kev tshawb fawb thiab thev naus laus zis, optical fiber tau nthuav dav hauv kev ua haujlwm ntawm kev sib txuas lus, hluav taws xob thiab hluav taws xob, dhau los ua cov khoom siv tshiab tseem ceeb. Lub tshuab fiber ntau txuas nrog ua ke kuj yeej cov neeg' s kev pom zoo nrog cov tshiab thiab yooj yim.
Ua tiav fais fab kis ua haujlwm
Larian Corporation ntawm Tebchaws Asmeskas siv ntse fiber ntau los ua kom tiav lub zog xa hluav taws xob muaj nuj nqi, qhib qhov kev lag luam-txoj hauv kev tshiab hauv thaj chaw fais fab. Lawv siv cov semiconductor laser diodes nyob rau ntawm qhov hloov qhov kawg hloov lub zog hluav taws xob mus rau lub teeb laser rau kev xa cov kab hluav taws xob, thiab siv cov hnub ci hlwb ua cov khoom txais kawg. Cov cuab yeej no siv 300-micron tuab gallium arsenide los ua cov txheej txheem insulating, them nrog 20-micron tuab hnub ci cell. Nws muab faib ua 6 qhov chaw ywj pheej, uas txuas nrog hauv cov txheej los ntawm huab cua kub pob zeb sib txuas. Thaum lub teeb laser kis tau los ntawm cov hluav taws xob fiber ntau ntaus lub hnub ci cell, lub teeb hluav taws xob tam sim ua hluav taws xob lub zog. Qhov voltage tsim los ntawm txhua thaj chaw muaj raws nraim li 1 volt, thiab rau thaj chaw nyob rau hauv series muaj qhov voltage ntawm 6 volts, uas yog txaus rau kev tswj Circuit Court ntawm feem ntau cov sensors.
dav siv
Yog tias lub zog ntawm lub laser diode yog txuas ntxiv nce thiab nruab nrog lub zog hloov cov kab ke, cov hluav taws xob fiber ntau kis tau los siv dav hauv kev siv tub rog, kev lag luam, kev lag luam thiab lwm yam. Fabkis' s Bogen laboratory, uas tshwj xeeb hauv cov khoos phis tawm, khoom siv hluav taws xob, teeb liab ua haujlwm thiab cov duab thev naus laus zis, siv cov khoom siv kho qhov muag (soliton) thiab cov xov paj me me kom ua tiav cov xov hluav taws xob tsis muaj kev sib kis hauv cov xov hluav taws xob. Cov thev naus laus zis no tuaj yeem daws cov teeb meem ntawm chromatic dispersion thiab non-linear effects tsis tas yuav tsum muaj ntau cov khoom siv rov ua dua tshiab raws cov kab hluav taws xob. Tsuas yog yuav tsum tsim teeb tsa tus kheej txhua 100 km lossis yog li ntawd thaum ua haujlwm. Lub cev tes dej khib nyiab tuaj yeem sib txuas yam tsis muaj kev cuam tshuam nrog lwm tus. Nws tau hais tias cov thev naus laus zis tshiab no tau siv hauv submarine lub nkoj loj hauv thaj tsam ntawm 6450-12900 km thiab tuaj yeem daws cov teeb meem kev sib txuas lus nyuaj. Cov lus tsis sib xyaw cov pa hluav taws xob kho qhov muag ua kom sib txuas lus tau tsim los ntawm Asmeskas kev sib txuas lus kev ruaj ntseg cov kws tshaj lij tau tsim tshwj xeeb rau kev ua lag luam niaj hnub no' Cov thev naus laus zis no pib hloov cov ntaub ntawv muaj txiaj ntsig xws li lub suab mus rau digital pulse Pib, thiab tom qab ntawd cim cov cim hluav taws xob digital pulse thiab hloov kho lawv ntawm cov microwave nqa khoom uas hloov tsis xwm yeem. Thaum xa, lub laser xa cov khoom xa mus rau cov neeg nqa khoom lub teeb liab nqa cov ntaub ntawv nqa mus rau lub txais ntawv los ntawm kev sib txuas lus kho qhov muag fiber ntau. Cov khoom siv laser txais tau tshwj xeeb siv tshuab tshwj xeeb los ua kom sib txuas thiab sib zog ua ke nrog kev xa cov cuab yeej laser, thiab thaum kawg ua tiav lub luag haujlwm ntawm rhuav tshem cov cim tseem ceeb ntawm cov xa khoom tsis xwm yeem. Siv cov thev naus laus zis, eavesdroppers yuav tsis muaj txiaj ntsig, lawv tsuas hnov nrov nrov yam tsis muaj kev xav. Australia Pauline nyuam qhuav tsim kho cov khoom nyhav fiber ntau uas tuaj yeem thauj cov tsheb nrog ib lub fiber ntau thiab ib lub ntsej muag laser. Hom fiber ntau no siv cov fiber ntau kho qhov muag nrog cov yam ntxwv tsis kam tshwj xeeb heev. Thaum nws tab tom mob siab lossis nro, qhov kho qhov muag yuav ua rau me ntsis pov tseg, ua rau cov yam ntxwv ntawm lub laser hloov. Lub sijhawm no, tus ntsuas yuav paub tam sim no hloov pauv thiab hloov mus rau hluav taws xob hloov teeb liab. Qhov no yog xav txog ntawm cov zaub teeb tsa ntawm lub ntsuas. Txij li cov fiber ntau ua los ntawm cov iav, nws muaj kev ya raws thiab hluav taws xob tsis kam. Tseem ceeb dua, nws yooj yim rau kev txhim kho thiab tswj. Nws yog qhov tsim nyog rau kev teeb tsa ntawm txoj kev tseem ceeb hauv cheeb tsam nroog, ib puag ncig cov chaw ua haujlwm, tshav dav hlau thiab kev khiav, tsev rau khoom, thiab chaw nres nkoj. Nruam ua haujlwm rau 24 teev. Yog li ntawd, ntxiv rau kev hnyav, nws kuj tseem tuaj yeem ua tus saib xyuas lub luag haujlwm, thiab qhov tseeb raug deb tshaj li ntawm cov khoom siv hluav taws xob uas twb muaj lawm.
Yas Optical Fiber
Raws li tsab ntawv tshaj tawm tshiab los ntawm Asmeskas phau ntawv xov xwm, cov yas kho qhov muag hluav taws xob tau tsim los ntawm Boston Optical Fiber Corporation, Massachusetts, muaj cov xov nrawm nrawm 30 zaus sai dua li cov qauv tooj liab tam sim no, thiab yog sib dua, hloov tau yooj yim, thiab tus nqi qis dua iav fiber ntau. Cov. Hom kho qhov muag no siv qhov kev txiav tawm ntawm lub teeb lossis dhia hom ntawm lub teeb hauv lub fiber ntau kom mus txog qhov kev sib kis tau ntau dua, thiab tuaj yeem xa cov ntaub ntawv ntawm qhov ceev ntawm 3 megabits ib pliag li ntawm 100 metres. Tam sim no, 370,000 kilometers ntawm submarine optical cables tau raug tso thoob plaws ntiaj teb. Qhov ntev no tuaj yeem yuav luag lub ntiaj teb 10 zaug. Ntxiv mus, vim tias lasers siv nyob rau ob qhov kawg, rov ua kom nrov dua rau cov kev ua kom tsis muaj suab tsis xav tau ntxiv thaum lub sijhawm sib kis, uas yuav txo tau cov nqi thiab hu tus nqi. Raws li cov lus ceeb toom, lub ntiaj teb' s loj tshaj plaws muaj peev txheej submarine optical cable txuas rau Tebchaws Europe thiab Tebchaws Meskas tab tom qhib. Cov submarine kev sib txuas lus fiber ntau optic cable txuas lub ntiaj teb tab tom raug nteg. Nov yog qhov haujlwm zoo tshaj plaws hauv kev ua haujlwm ntawm kev sib txuas lus nyob rau xyoo 20 thiab tau txais kev txhawb nqa los ntawm 30 lub koom haum hauv kev xa xov thoob ntiaj teb thoob ntiaj teb. Nws hla hiav txwv Atlantic, hla hiav txwv Mediterranean, hla hiav txwv liab thiab Hiav Txwv Indian, thiab hla tus Strait of Malacca mus rau hauv Dej hiav txwv Pacific. Nrog tag nrho ntev ntawm ze li ntawm 320,000 kis lus mev, nws txuas rau 175 lub teb chaws thiab thaj chaw, thiab tuaj yeem ua 2.4 lab lub xov tooj lossis xa tau ntau pua txhiab tus ntawm cov duab hauv tib lub sijhawm. Tag nrho lub phiaj xwm muaj nuj nqis 14 billion nyiaj US thiab xav tias yuav ua tiav rau xyoo 2003.
Tsa muaj pes tsawg leeg
Optical fiber thev naus laus zis feem ntau muaj peb ntu: qhov teeb liab kho qhov muag xa mus rau qhov kawg, optical fiber siv los xa cov teeb liab kho qhov muag, thiab lub teeb liab kho qhov muag tau txais qhov kawg.
Kev ua haujlwm ntawm lub teeb liab kis mus rau qhov kawg yog los hloov lub teeb liab hluav taws xob xa mus rau hauv lub teeb liab kho qhov muag los ntawm kev siv hluav taws xob hloov kho hluav taws xob. Tam sim no, qhov kev xa cov tshuab xa hluav taws xob kawg hloov hluav taws xob feem ntau siv lub teeb tsa hluav taws xob lossis lub tshuab xa hluav taws xob laser. Cov zis hluav taws xob lub zog ntawm lub teeb hluav taws xob hloov hluav taws xob muaj ntau tsawg, qhov taw qhia cov lus piav qhia tau tsawg dua, tab sis tus nqi pheej yig. Nws cov tso zis hluav taws xob lub zog thiab tsav hluav taws xob tam sim no yog cov kab ncaj qha nyob rau hauv qee qhov, uas ntau haum rau luv-nrug, qis-nrawm, thiab cov cim xa hluav taws xob; Lub zog tawm ntawm lub diode yog loj, lub teeb liab ntsuas tus nqi yog siab, tab sis tus nqi kuj siab, thiab nws tsim nyog rau kev tiv thaiv ntev, kev kub ceev, xov tooj digital kis. Kev ua haujlwm ntawm cov hluav taws xob kho qhov muag yog xa cov teeb liab kho qhov muag ntawm lub teeb liab mus rau qhov kawg tau txais ntawm lub teeb liab kho qhov muag nrog kev tawm suab thiab kev cuam tshuam tsawg li sai tau. Lub sijhawm tam sim no, cov kab hluav taws xob feem ntau siv rau hauv qhov ze infrared band.0.84& micro; m 、 1.31& micro; m 、 1.55& micro; mMulti-mode lossis ib hom quartz fiber ntau nrog transmittance zoo. Kev ua haujlwm ntawm lub teeb liab kho qhov muag tau txais qhov kawg yog kom rov kho qhov teeb liab kho qhov muag kom raug hluav taws xob teeb liab los ntawm cov khoom siv hluav taws xob photoelectric hloov dua siab tshiab. Cov cuab yeej hluav taws xob photoelectric conversion feem ntau siv lub tshuab hluav taws xob semiconductor photodiode lossis avalanche photodiode. Lub teeb hluav taws xob hloov lub teeb ci ntawm lub teeb ci sib txuas ntawm lub tshuab xa hluav taws xob fiber ntau yuav tsum sib phim ntawm cov kab hluav taws xob ntawm lub qhov poob qis ntawm lub qhov xa hluav taws xob thiab cov lus teb siab tshaj plaws ntawm cov khoom siv hluav taws xob photoelectric. Cov khoom xa tawm kawg electro-kho qhov muag hloov khoom siv nruab nrab ntawm cov pa roj teeb hluav taws xob ua ntu nruab nrab ntawm0.84& micro; mLub siab nyob ze-infrared semiconductor lub teeb ci hluav taws xob, cov kis hluav taws xob adopts multimode quartz fiber ntau, thiab tau txais qhov kawg photoelectric hloov dua siab tshiab cuab yeej adopts lub ntsiab lus teb wavelength ntawm 0.8& micro; m-0.9& micro; mSilicon photodiode. Txhua ntu yuav qhia ntxiv rau hauv qab no.
Fais lub teeb liab kho qhov muag
Kev tsav tsheb thiab ntsuas hluav taws xob ntawm LED siv nyob rau hauv qhov system tau qhia hauv Daim duab 2. Lub teeb liab ua qauv siv cov txheej txheem ntawm kev siv lub teeb taws, thiab lub teeb ci hloov kho potentiometer raug xa mus rau kho cov kev tsav tsheb zoo li qub ntws los ntawm LED, yog li hloov lub teeb tsa hluav taws xob ntawm lub teeb hluav taws xob ntawm LED, Qhov teeb tsa tsav zoo li qub kev hloov kho tam sim no yog 0-20 mA, coj los ntsuas cov nqi ntawm cov vaj huam sib luag lub teeb kis mus rau kev tsav tsheb pom tus nqi 0-2000 units, thaum tsav tsheb tam sim no me, lub teeb emitting diode emission lub zog thiab cov tsav tsheb tam sim no yog cov kab tawm suab, suab Lub teeb liab txuas mus rau qhov tsis zoo tawm davhlau ya nyob twg ntawm lwm qhov op amp tom qab raug rho tawm los ntawm tus capacitor, resistor network thiab op amp, thiab superimposed nrog cov tsav tsheb zoo li qub ntawm lub teeb- emitting diode ua kom lub teeb pom kev zoo xa cov cim hluav taws xob uas hloov nrog lub suab teeb liab, thiab tom qab ntawd los ntawm cov kab hluav taws xob kho qhov muag ua ke Th yog lub teeb liab kho qhov muag txuas nrog cov kis tau tus mob. Lub qes kawg ntawm lub teeb liab kis tau txais kev txiav txim siab tau txiav txim siab los ntawm lub capacitor thiab resistor network, thiab cov lus teb tsawg kawg ntawm cov kab ke tsis tshaj 20Hz
Folding lub teeb liab txais
Nws yog daim duab ua haujlwm txoj cai ntawm kev teeb tsa kho qhov muag tau txais qhov kawg. Cov kis hluav taws xob cov khub niam txiv lub teeb liab kho qhov muag ntawm qhov xa mus xaus rau qhov photoelectric hloov dua siab tshiab photodiode los ntawm cov kab hluav taws xob optical txuas. Lub photodiode hloov lub kho qhov muag teeb rau hauv lub teeb liab tam sim no sib npaug rau nws. Lub diode yuav tsum rov qab-muaj kev cuam tshuam thaum siv, thiab cov teeb liab photocurrent yog hloov mus rau hauv lub teeb liab hluav taws xob sib npaug rau nws los ntawm qhov hloov tam sim no-voltage ntawm op amp. Lub suab teeb tsa muaj nyob rau hauv lub teeb liab hluav taws xob txuas mus rau lub suab tso tawm hluav taws xob kom tsav lub suab nrov kom hnov suab los ntawm tus capacitor thiab kev tawm tsam. Qhov nquag teb ntawm lub photodiode feem ntau yog siab, thiab lub siab teb ntawm lub system feem ntau nyob ntawm lub teb cov zaus ntawm cov ua haujlwm amplifier.
Kis fiber ntau
Tam sim no, cov fiber ntau siv rau kev sib txuas lus kho qhov muag feem ntau siv silica fiber. Nws yog them nrog cladding txheej nrog qhov me me refractive index n1 hauv qhov tseem ceeb nrog loj refractive index n2. Lub teeb tau siab faib rau ntawm kev sib tshuam ntawm cov tub ntxhais thiab cov cladding. Qhov xav txog yog txwv tsis pub nthuav tawm hauv qhov tseem ceeb ntawm qhov fiber. Raws li pom hauv daim duab 5, qhov kho qhov muag fiber yog qhov tseeb yog hom ntawm dielectric waveguide. Lub teeb muab xauv rau hauv qhov kho qhov muag thiab tsuas yog kis tau raws kab ke kho qhov muag. Lub hauv paus loj ntawm cov khoom siv fiber ntau yog feem ntau los ntawm ob peb microns rau ntau pua microns. Raws li cov kis teeb hom, nws muaj peev xwm raug faib ua ntau hom fiber ntau thiab ntau hom fiber ntau, thiab tuaj yeem muab faib ua cov qib refractive index qib hom thiab refractive index muab fiber ntau raws li txoj kev sib txawv ntawm fiber ntau refractive index faib. Cov refractive index qib fiber ntau muaj ob daim circularly symmetrical coaxial media, ob qho tib si uas yog cov tsis zoo ib yam hauv kev ntxhib los mos, tab sis muaj cov ntsiab lus sib txawv refractive. Qhov refractive index ntawm lub txheej txheej sab nraud qis dua li ntawm txheej ntawm puab.
Ib txheej fiber ntau yog ib hom fiber ntau uas nws qhov ntsuas phom rau qhov zoo sib tshooj yog ntsuas raws ntu hla ntawm cov fiber. Lub hom phiaj ntawm kev hloov pauv ntawm qhov ntsuas rov qab yog ua kom cov pab pawg rau kev hloov ntawm ntau hom qauv zoo sib xws, thiaj li txo cov qauv kev hloov pauv thiab nce kev sib txuas lus. Multimode refractive index kauj ruam-hom fiber ntau tsim cov kev sib txuam sib txuam vim muaj kev sib txawv pab pawg sib txawv ntawm txhua hom kis, thiab cov kab xa xov kis tau raug txwv. Multimode refractive index muab fiber ntau nce cov teeb liab kis kab mob vim nws qhov tshwj xeeb refractive index faib, uas ua rau pab pawg ceev ntawm txhua hom kis tau tib yam. Ib hom fiber ntau yog cov roj carbon fiber uas kis tau ib tus kho qhov muag tau kho tib hom, thiab ib hom fiber ntau tuaj yeem xa tawm lub teeb liab ntau tshaj. Tam sim no, ib hom fiber ntau kho qhov muag feem ntau siv cov kev sib txuas lus kho qhov muag ntev.
Lub ntsiab kev ntsuas ntawm silica fiber muaj xws li attenuation yam ntxwv, zauv aperture thiab dispersion. Cov Xov Tooj Nruab Nrab: Cov Zes Zis Qhia txog cov yam ntxwv ntawm fiber ntau ua ke nrog lub teeb ci, cov ntsuas hluav taws xob thiab lwm yam khoom siv kho qhov muag. Nws qhov loj me qhia qhov muaj peev xwm ntawm cov roj carbon fiber ntau kom tau txais kev sib. Raws li pom hauv daim duab 5, qhov teeb meem tshwm sim ntawm lub ntsej muag kawg ntawm lub ntsej muag kho qhov muag tsis pub dhau lub kaum sab xis ntawm lub qhov muag 2θmax tau zoo siab ntawm qhov cuam tshuam sab hauv ntawm qhov kho qhov muag kom xa tau, thiab cov teeb meem tshwm sim ntawm lub ntsej muag kawg ntawm optical fiber sab nraum. 2θmax ntau yog Sab hauv interface ntawm lub fiber tsis ua rau tag nrho cov kev xav txog tab sis yog kis rau cov cladding thiab tam sim no attenuated. Cov lej aperture ntawm lub fiber yog txhais raws li: NA=Sinθmax, nws tus nqi yog feem ntau ntawm 0.1 thiab 0.6, thiab sib nug xov θmax yog nruab nrab ntawm 90 thiab 330, Multimode fiber muaj lub loj loj aperture, thiab cov lej aperture ntawm ib hom fiber ntau yog qhov me me, yog li feem ntau ib-hom fiber ntau xav tau LD semiconductor laser ua nws lub teeb ci.