Qhov zoo ntawm kev sib txuas lus fiber ntau optic:
● Muaj peev xwm sib txuas lus loj
● Ntev relay nrug
● Tsis muaj hluav taws xob cuam tshuam
● Cov peev txheej nplua nuj
● Lub teeb yuag thiab me me
Keeb kwm luv luv ntawm Optical Communications
Ntau tshaj 2000 xyoo dhau los, lub beacon-lights, semaphores
1880, kho qhov muag xov tooj-wireless optical kev sib txuas lus
Xyoo 1970, kev sib txuas lus fiber ntau
● Xyoo 1966, "Txiv Plig ntawm Optical Fiber", Dr. Gao Yong thawj zaug tau npaj lub tswv yim ntawm kev sib txuas lus fiber ntau.
● Xyoo 1970, Bell Yan lub koom haum Lin Yanxiong yog ib lub laser semiconductor uas tuaj yeem ua haujlwm tsis tu ncua ntawm chav tsev kub.
● Xyoo 1970, Corning's Kapron ua rau poob ntawm 20dB / km fiber ntau.
● Xyoo 1977, Chicago thawj kab lag luam ntawm 45Mb / s.
Electromagnetic spectrum
Kev sib txuas lus band faib thiab sib kis xov xwm
Refraction / reflection thiab tag nrho cov kev xav ntawm lub teeb
Vim hais tias lub teeb txawv ntawm cov khoom sib txawv, thaum lub teeb tawm ntawm ib yam khoom mus rau lwm tus, refraction thiab reflection tshwm sim ntawm qhov sib cuam tshuam ntawm ob yam khoom.Ntxiv mus, lub kaum sab xis ntawm lub teeb refracted txawv nrog lub kaum sab xis ntawm qhov teeb meem teeb.Thaum lub kaum sab xis ntawm qhov teeb meem tshwm sim los yog tshaj ib lub kaum ntse ntse, lub teeb refracted yuav ploj mus, thiab tag nrho cov teeb meem teeb meem yuav rov qab los.Qhov no yog tag nrho cov reflection ntawm lub teeb.Cov ntaub ntawv sib txawv muaj qhov sib txawv ntawm qhov sib txawv rau tib lub wavelength ntawm lub teeb (uas yog, cov ntaub ntawv sib txawv muaj qhov sib txawv refractive indices), thiab tib cov ntaub ntawv muaj qhov sib txawv ntawm qhov sib txawv rau qhov sib txawv wavelengths ntawm lub teeb.Kev sib txuas lus ntawm fiber ntau yog ua raws li cov hauv paus ntsiab lus saum toj no.
Reflectivity tis: Ib qho tseem ceeb tsis zoo rau cov khoom siv kho qhov muag yog qhov refractive index, uas yog sawv cev los ntawm N. Qhov piv ntawm qhov ceev ntawm lub teeb C hauv lub tshuab nqus tsev mus rau qhov ceev ntawm lub teeb V nyob rau hauv cov khoom yog lub refractive index ntawm cov khoom.
N = C / V
Lub refractive index ntawm quartz iav rau optical fiber kev sib txuas lus yog hais txog 1.5.
Fiber qauv
Fiber liab qab fiber ntau feem ntau muab faib ua peb txheej:
Thawj txheej: qhov chaw siab refractive index iav core (tub ntxhais txoj kab uas hla feem ntau yog 9-10μm, (ib hom) 50 lossis 62.5 (ntau hom).
Qhov thib ob txheej: nruab nrab yog qhov qis refractive index silica iav cladding (lub cheeb yog feem ntau 125μm).
Qhov thib peb txheej: sab nraud yog txheej txheej rau kev txhawb nqa.
1) core: siab refractive index, siv los xa lub teeb;
2) Cladding txheej: qis refractive index, tsim tag nrho cov kev xav ntawm lub hauv paus;
3) Lub tsho tiv thaiv: Nws muaj lub zog siab thiab tuaj yeem tiv taus qhov cuam tshuam loj los tiv thaiv cov fiber ntau optical.
3mm optical cable: txiv kab ntxwv, MM, ntau hom;daj, SM, ib hom
Fiber ntau
Sab nraud txoj kab uas hla yog feem ntau 125um (nruab nrab 100um ib cov plaub hau)
Sab hauv txoj kab uas hla: ib hom 9um;Multimode 50 / 62.5um
Numerical aperture
Tsis yog tag nrho cov teeb pom kev zoo ntawm lub ntsej muag kawg ntawm cov khoom siv kho qhov muag tuaj yeem kis tau los ntawm cov khoom siv kho qhov muag, tab sis tsuas yog qhov teeb meem teeb pom kev nyob rau hauv qee qhov ntawm cov ces kaum.Lub kaum sab xis no yog hu ua tus lej aperture ntawm fiber ntau.Ib tug loj tus lej aperture ntawm optical fiber ntau yog qhov zoo rau kev docking ntawm cov fiber ntau optical.Cov tuam ntxhab sib txawv muaj cov lej sib txawv.
Hom fiber ntau
Raws li kev sib kis ntawm lub teeb nyob rau hauv optical fiber, nws tuaj yeem muab faib ua:
Ntau hom (cov ntawv luv: MM);Hom Ib Leeg (Sab sauv: SM)
Multimode fiber ntau: Lub hauv paus iav core yog tuab (50 lossis 62.5μm) thiab tuaj yeem xa lub teeb hauv ntau hom.Txawm li cas los xij, nws qhov sib txawv ntawm qhov sib txawv yog qhov loj, uas txwv qhov zaus ntawm kev xa cov cim digital, thiab nws yuav dhau los ua qhov hnyav dua nrog kev nce ntxiv.Piv txwv li: 600MB / KM fiber ntau tsuas muaj 300MB bandwidth ntawm 2KM.Yog li ntawd, qhov kev ncua deb ntawm ntau hom fiber ntau yog luv luv, feem ntau tsuas yog ob peb kilometers.
Ib hom fiber ntau: Lub hauv paus iav core yog nyias nyias (txoj kab uas hla feem ntau yog 9 lossis 10μm), thiab tsuas yog kis tau lub teeb nyob rau hauv ib hom.Nyob rau hauv qhov tseeb, nws yog ib hom step-type optical fiber, tab sis cov tub ntxhais txoj kab uas hla yog me me heev.Nyob rau hauv txoj kev xav, tsuas yog lub teeb ncaj qha ntawm ib txoj kev propagation yog tso cai rau nkag mus rau lub fiber thiab propagate ncaj qha rau hauv lub fiber core.Lub fiber pulse yog NW nyuam qhuav stretched.Yog li ntawd, nws inter-mode dispersion yog me me thiab haum rau kev sib txuas lus tej thaj chaw deb, tab sis nws chromatic dispersion plays lub luag haujlwm tseem ceeb.Nyob rau hauv txoj kev no, ib hom fiber ntau muaj cov kev xav tau ntau dua rau qhov dav dav thiab kev ruaj ntseg ntawm lub teeb ci, uas yog, qhov dav spectral yog nqaim thiab kev ruaj ntseg zoo..
Classification ntawm optical fibers
Los ntawm cov khoom siv:
Cov iav fiber ntau: Cov tub ntxhais thiab cladding yog ua los ntawm iav, nrog kev poob me me, kev sib kis ntev thiab tus nqi siab;
Rubber-them silicon optical fiber: cov tub ntxhais yog iav thiab cladding yog yas, uas muaj cov yam ntxwv zoo sib xws rau iav fiber ntau thiab tus nqi qis dua;
Yas kho qhov muag fiber ntau: Ob lub hauv paus thiab cov cladding yog yas, nrog kev poob loj, kev sib kis luv luv, thiab tus nqi qis.Feem ntau yog siv rau cov khoom siv hauv tsev, suab, thiab kev xa cov duab luv luv.
Raws li qhov zoo tshaj plaws kis tau tus mob lub qhov rais: pa ib hom fiber ntau thiab dispersion-hloov ib hom fiber ntau.
Hom Pa: Lub tsev tsim kho qhov muag fiber ntau optimizes fiber ntau kis tau tus mob ntawm ib lub wavelength ntawm lub teeb, xws li 1300nm.
Dispersion-hloov hom: Cov khoom siv fiber ntau optics optimizes fiber ntau kis tau tus mob ntawm ob lub teeb ntawm lub teeb, xws li: 1300nm thiab 1550nm.
Kev hloov pauv sai: Qhov ntsuas qhov cuam tshuam ntawm cov tub ntxhais fiber ntau rau cov iav cladding yog nrawm.Nws muaj tus nqi qis thiab siab inter-hom dispersion.Haum rau kev sib txuas lus luv luv luv luv, xws li kev tswj hwm kev lag luam.Txawm li cas los xij, ib hom fiber ntau siv hom kev hloov pauv vim yog qhov sib cuam tshuam me me.
Gradient fiber ntau: qhov refractive Performance index ntawm cov tub ntxhais fiber ntau rau cov iav cladding yog maj txo, tso cai rau high-mode lub teeb rau propagate nyob rau hauv ib tug sinusoidal daim ntawv, uas yuav txo tau dispersion ntawm hom, nce fiber ntau bandwidth, thiab nce kis tau tus mob, tab sis tus nqi yog. Hom fiber ntau yog feem ntau qib fiber ntau.
Common fiber specifications
Fiber ntau:
1) Ib hom tub ntxhais txoj kab uas hla: 9/125μm, 10/125 ibμm
2) Sab nrauv cladding txoj kab uas hla (2D) = 125μm
3) Cov txheej txheej sab nraud = 250μm
4) Pigtail: 300μm
5) Multimode: 50/125μm, European txheem;62.5 / 125μm, American txuj
6) Kev lag luam, kev kho mob thiab kev sib txuas qis: 100 / 140μm, 200/230 ibμm
7) Yas: 98/1000μm, siv rau kev tswj tsheb
Fiber ntau attenuation
Cov yam tseem ceeb uas ua rau muaj fiber ntau attenuation yog: intrinsic, dabtsi yog khoov, squeezing, impurities, unevenness thiab pob tw.
Intrinsic: Nws yog qhov poob ntawm cov fiber ntau optical, suav nrog: Rayleigh tawg, qhov nqus dej, thiab lwm yam.
Khoov: Thaum lub fiber yog khoov, lub teeb nyob rau hauv ib feem ntawm fiber ntau yuav ploj vim tawg, ua rau poob.
Squeezing: poob los ntawm me ntsis khoov ntawm fiber ntau thaum nws yog nyem.
Impurities: impurities nyob rau hauv ib qho optical fiber absorb thiab tawg lub teeb kis tau nyob rau hauv fiber, ua rau poob.
Non-uniform: Qhov poob los ntawm qhov tsis sib xws refractive index ntawm cov khoom fiber ntau.
Docking: Poob generated thaum fiber ntau docking, xws li: sib txawv axes (ib hom fiber ntau coaxiality yuav tsum yog tsawg dua 0.8μm), lub ntsej muag kawg tsis yog perpendicular rau lub axis, lub ntsej muag kawg yog tsis sib xws, lub taub qab ntawm lub taub hau tsis sib xws, thiab qhov zoo ntawm splicing tsis zoo.
Hom ntawm optical cable
1) Raws li cov txheej txheem nteg: tus kheej txhawb nqa nyiaj siv ua haujlwm kho qhov muag cables, pipeline optical cables, armored faus optical cables thiab submarine optical cables.
2) Raws li cov qauv ntawm cov khoom siv kho qhov muag, muaj: bundled tube kho qhov muag cable, txheej twisted kho qhov muag cable, nruj-tuav kho qhov muag cable, ribbon kho qhov muag cable, non-metal optical cable thiab branchable optical cable.
3) Raws li lub hom phiaj: optical cables rau kev sib txuas lus nyob deb, sab nraum zoov kho qhov muag cables rau luv luv, hybrid optical cables, thiab kho qhov muag cables rau cov tsev.
Kev sib txuas thiab txiav tawm ntawm cov kab hluav taws xob kho qhov muag
Kev sib txuas thiab kev txiav tawm ntawm cov kab hluav taws xob kho qhov muag yog cov kev txawj ntse uas cov neeg ua haujlwm kho qhov muag yuav tsum paub.
Classification ntawm optical fiber txuas technology:
1) Kev sib txuas thev naus laus zis ntawm optical fiber ntau thiab kev sib txuas thev naus laus zis ntawm optical cable yog ob feem.
2) Qhov kawg ntawm qhov kho qhov muag cable zoo ib yam li kev sib txuas ntawm cov khoom siv kho qhov muag, tshwj tsis yog tias kev ua haujlwm yuav tsum sib txawv vim cov khoom sib txawv ntawm cov khoom sib txuas.
Hom kev sib txuas ntawm fiber ntau
Fiber optic cable txuas feem ntau tuaj yeem muab faib ua ob pawg:
1) Tsau kev sib txuas ntawm optical fiber (feem ntau hu ua tuag connector).Feem ntau siv optical fiber fusion splicer;siv rau lub taub hau ncaj qha ntawm optical cable.
2) Lub active connector ntawm optical fiber (feem ntau hu ua tus nyob connector).Siv cov connectors tshem tau (feem ntau hu ua xoob pob qij txha).Rau fiber ntau jumper, khoom siv sib txuas, thiab lwm yam.
Vim qhov ua tsis tiav ntawm lub ntsej muag kawg ntawm cov khoom siv kho qhov muag thiab qhov tsis sib xws ntawm lub siab ntawm lub ntsej muag kawg ntawm cov khoom siv kho qhov muag, qhov splice poob ntawm qhov muag fiber ntau los ntawm ib qho kev tso tawm tseem loj heev, thiab cov txheej txheem fusion thib ob. yog tam sim no siv.Ua ntej, preheat thiab tso tawm lub ntsej muag kawg ntawm cov fiber ntau, tsim lub ntsej muag kawg, tshem tawm cov plua plav thiab cov khib nyiab, thiab ua kom lub siab kawg ntawm cov fiber ntau los ntawm preheating.
Kev soj ntsuam txoj hauv kev rau kev sib txuas ntawm fiber ntau optical poob
Muaj peb txoj hauv kev los saib xyuas kev sib txuas ntawm fiber ntau:
1. Saib xyuas ntawm lub splicer.
2. Kev saib xyuas lub teeb pom kev zoo thiab lub ntsuas hluav taws xob kho qhov muag.
3.OTDR txoj kev ntsuas
Txoj kev ua haujlwm ntawm optical fiber txuas
Optical fiber txuas kev ua haujlwm feem ntau muab faib ua:
1. Kev tuav ntawm fiber ntau lub ntsej muag.
2. Kev sib txuas ntawm cov khoom siv kho qhov muag fiber ntau.
3. Splicing ntawm optical fiber.
4. Kev tiv thaiv ntawm optical fiber connectors.
5. Muaj tsib kauj ruam rau lub tais fiber ntau ntxiv.
Feem ntau, kev sib txuas ntawm tag nrho optical cable yog ua raws li cov kauj ruam hauv qab no:
Kauj Ruam 1: ntev ntev zoo heev, qhib thiab strip lub kho qhov muag cable, tshem tawm cov cable sheath
Kauj Ruam 2: Ntxuav thiab tshem tawm cov roj av filling muab tshuaj txhuam rau hauv cov khoom siv kho qhov muag.
Kauj Ruam 3: Muab cov fiber ntau.
Kauj Ruam 4: Txheeb xyuas tus naj npawb ntawm cov cores fiber ntau, ua cov fiber ntau sib txuas, thiab xyuas seb cov xim fiber ntau puas yog.
Kauj Ruam 5: Txhim kho lub plawv kev sib txuas;
Kauj Ruam 6: Ntau yam kev pabcuam kab khub, suav nrog cov kab lag luam, cov kab tswj kab, cov kab thaiv hauv av, thiab lwm yam.
Kauj Ruam 7: Txuas cov fiber ntau.
Kauj Ruam 8: Tiv thaiv cov khoom siv fiber ntau optical;
Kauj Ruam 9: khaws cov khoom seem ntawm cov fiber ntau;
Kauj Ruam 10: Ua kom tiav qhov kev sib txuas ntawm lub tsho optical cable;
Kauj Ruam 11: Kev tiv thaiv fiber ntau optic connectors
Fiber poob
1310 nm: 0.35 ~ 0.5 dB / Km
1550 nm: 0.2 ~ 0.3dB / Km
850 nm: 2.3 txog 3.4 dB / Km
Optical fiber ntau fusion point poob: 0.08dB / point
Fiber splicing point 1 point / 2km
Cov npe fiber ntau
1) Attenuation
Attenuation: lub zog poob thaum lub teeb kis tau rau hauv fiber ntau optical, ib hom fiber ntau 1310nm 0.4 ~ 0.6dB / km, 1550nm 0.2 ~ 0.3dB / km;yas multimode fiber ntau 300dB / km
2) Dispersion
Dispersion: Lub bandwidth ntawm lub teeb pulses yog nce tom qab taug kev ib qho deb ntawm fiber ntau.Nws yog lub ntsiab tseem ceeb txwv qhov kis tus nqi.
Inter-mode dispersion: tshwm sim tsuas yog nyob rau hauv multimode fibers, vim hais tias txawv hom ntawm lub teeb mus txawv tebchaws.
Material dispersion: sib txawv wavelengths ntawm lub teeb mus txawv tebchaws ntawm txawv speeds.
Waveguide dispersion: Qhov no tshwm sim vim lub teeb lub zog mus ntawm qhov sib txawv me ntsis thaum nws mus los ntawm cov tub ntxhais thiab cladding.Nyob rau hauv ib hom fiber ntau, nws yog ib qho tseem ceeb heev los hloov cov dispersion ntawm cov fiber ntau los ntawm kev hloov cov qauv sab hauv ntawm cov fiber.
Hom Fiber
G.652 xoom dispersion point yog nyob ib ncig ntawm 1300nm
G.653 xoom dispersion point yog nyob ib ncig ntawm 1550nm
G.654 tsis zoo dispersion fiber ntau
G.655 dispersion-hloov fiber ntau
Tag nrho yoj fiber ntau
3) tawg
Vim lub teeb pom kev tsis zoo ntawm lub teeb, qhov poob ntawm lub teeb lub zog yog tshwm sim, thiab kev sib kis ntawm lub teeb nyob rau lub sijhawm no tsis muaj kev ncaj ncees zoo.
Kev paub yooj yim ntawm fiber ntau optic system
Taw qhia txog kev tsim qauv thiab kev ua haujlwm ntawm cov txheej txheem fiber ntau optic:
1. Kev xa tawm: hloov hluav taws xob teeb liab rau hauv cov teeb liab kho qhov muag;
2. Chav tsev kis tau tus mob: nruab nrab nqa cov teeb liab kho qhov muag;
3. Txais chav tsev: tau txais cov teeb liab kho qhov muag thiab hloov mus rau hauv cov teeb liab hluav taws xob;
4. Txuas lub cuab yeej: txuas cov khoom siv kho qhov muag rau lub teeb pom kev zoo, nrhiav pom lub teeb thiab lwm yam khoom siv kho qhov muag.
Hom connector hom
Connector kawg lub ntsej muag hom
Coupler
Lub luag haujlwm tseem ceeb yog faib cov teeb liab kho qhov muag.Cov ntawv thov tseem ceeb yog nyob rau hauv kev sib txuas ntawm fiber ntau optical, tshwj xeeb tshaj yog nyob rau hauv cheeb tsam hauv cheeb tsam network thiab hauv wavelength division multiplexing devices.
yooj yim qauv
Lub coupler yog ib tug bidirectional passive ntaus ntawv.Cov ntaub ntawv yooj yim yog tsob ntoo thiab hnub qub.Lub coupler sib haum mus rau lub splitter.
WDM
WDM—Wavelength Division Multiplexer xa ntau lub teeb liab kho qhov muag hauv ib qho khoom siv fiber ntau.Cov teeb liab kho qhov muag no muaj ntau zaus thiab cov xim sib txawv.Lub WDM multiplexer yog ob peb ntau lub teeb liab kho qhov muag rau hauv tib lub fiber ntau optical;lub demultiplexing multiplexer yog kom paub qhov txawv ntawm ntau qhov chaw kho qhov muag los ntawm ib qho fiber ntau optical.
Wavelength Division Multiplexer (Lus dab neeg)
Lub ntsiab lus ntawm pulses hauv digital systems:
1. Amplitude: Qhov siab ntawm cov mem tes sawv cev rau lub zog kho qhov muag hauv lub tshuab fiber ntau.
2. Lub sij hawm sawv: lub sij hawm yuav tsum tau rau lub mem tes nce ntawm 10% mus rau 90% ntawm qhov siab tshaj plaws amplitude.
3. Lub sij hawm caij nplooj ntoos zeeg: lub sij hawm yuav tsum tau rau lub mem tes poob ntawm 90% mus rau 10% ntawm lub amplitude.
4. Pulse dav: Qhov dav ntawm lub mem tes ntawm 50% amplitude txoj hauj lwm, qhia nyob rau hauv lub sij hawm.
5. Lub voj voog: lub sijhawm tshwj xeeb mem tes yog lub sijhawm ua haujlwm yuav tsum ua kom tiav ib lub voj voog.
6. Extinction ratio: Qhov piv ntawm 1 teeb liab lub teeb lub zog rau 0 teeb liab teeb lub zog.
Kev txhais ntawm cov chav nyob hauv kev sib txuas lus optical fiber ntau:
1.dB = 10 log10 (Pout / Pin)
Pout: tso zis zog;Pin: input zog
2. dBm = 10 log10 (P / 1mw), uas yog siv dav hauv kev sib txuas lus engineering;nws feem ntau sawv cev rau lub hwj chim kho qhov muag nrog 1 milliwatt raws li kev siv;
piv txwv:-10dBm txhais tau hais tias lub zog kho qhov muag sib npaug rau 100uw.
3.dBu = 10 log10 (P / 1uw)