Kev xa cov ntaub ntawv kho qhov muag ua haujlwm los ntawm lub teeb pulses

 

Kev xa cov ntaub ntawv kho qhov muag hloov cov ntaub ntawv digital rau hauv lub teeb pulses uas taug kev los ntawm fiber ntau optic cables lossis qhov chaw dawb. Lub transmitter encodes binary cov ntaub ntawv (ib tug thiab xoom) raws li flashes sai ntawm lub teeb, feem ntau yog siv lasers los yog LEDs, uas ces propagate los ntawm ultra-thin iav fibers ntawm tag nrho cov sab hauv xav txog. Thaum kawg tau txais, photodetectors hloov cov teeb pulses rov qab rau hauv hluav taws xob teeb liab uas cov cuab yeej siv tau ua tiav.

 

 

Binary lus ntawm lub teeb

 

Ntawm nws qhov tseem ceeb, kev xa cov ntaub ntawv kho qhov muag ua haujlwm ntawm tib lub hauv paus ntsiab lus raws li Morse code: cov ntaub ntawv encoded raws li cov qauv ntawm kev muaj thiab tsis tuaj. Qhov txawv yog nyob rau hauv nplai thiab ceev. Thaum Morse code siv cov cim ntev thiab luv luv ntawm tib neeg- pom kev nrawm, cov tshuab kho qhov muag xa ntau lab lub teeb pulses ib ob, nrog rau txhua tus mem tes sawv cev rau tus lej binary.

Thaum koj xa email lossis kwj ib vis dis aus, koj lub cuab yeej ua ntej hloov cov ntaub ntawv ntawd rau hauv binary code-tsis muaj qhov kawg ntawm 1s thiab 0s. Ib tug optical transmitter ces txhais no binary kwj mus rau hauv lub teeb. Lub pulse ntawm lub teeb sawv cev rau "1," thaum qhov tsis muaj lub teeb (los yog cov mem tes dimmer) sawv cev rau "0." Txoj kev encoding ncaj nraim no, hu ua kev hloov kho kev siv zog nrog kev tshawb pom ncaj qha, ua tiav cov ntaub ntawv tus nqi uas cov tshuab hluav taws xob tsis tuaj yeem sib xws.

Qhov kom zoo dua qhov ceev yog los ntawm lub teeb lub hauv paus khoom. Electromagnetic nthwv dej nyob rau hauv lub optical spectrum oscillate ntawm frequencies ntsuas nyob rau hauv pua pua ntawm terahertz- kev txiav txim ntawm magnitude sai tshaj lub xov tooj cua zaus siv nyob rau hauv ib txwm wireless kev sib txuas lus. Qhov ntau zaus no txhais ncaj qha rau hauv cov ntaub ntawv ntau dua - nqa peev xwm.

Cov tshuab kho qhov muag niaj hnub tau thawb cov peev txheej no mus rau qib txawv txawv. Hauv xyoo 2024, cov kws tshawb fawb ntawm Nyij Pooj Lub Tsev Haujlwm Saib Xyuas Kev Tshawb Fawb thiab Kev Sib Txuas Lus tau ua tiav cov ntaub ntawv - tawg 402 terabits ib thib ob uas siv cov qauv fiber ntau. Txhawm rau muab qhov ntawd tso rau hauv qhov kev xav, qhov ntawd yog qhov bandwidth txaus los rub tawm kwv yees li 50,000 siab -txhais tsos hauv ib pliag.

 

Lub teeb nyob li cas hauv Fiber

 

Lub physics ua kom cov ntaub ntawv kho qhov muag kis tau los ntawm qhov tshwm sim hu ua tag nrho cov kev xav sab hauv. Nkag siab txog cov ntsiab cai no yuav tsum tau tshuaj xyuas cov qauv ntawm fiber ntau optic cables thiab seb lub teeb coj li cas ntawm cov khoom ciam teb.

Ib qho fiber ntau optical muaj ob txheej iav thawj: lub hauv paus tseem ceeb uas lub teeb mus, thiab ib puag ncig cladding nrog cov khoom sib txawv. Cov tub ntxhais feem ntau muaj txoj kab uas hla ntawm 8 thiab 50 microns (thinner dua li tib neeg cov plaub hau), thaum lub cladding txuas mus txog 125 microns. Ob qho khoom siv yog cov iav ntshiab txawv txawv, tab sis lawv txawv ntawm lawv qhov ntsuas qhov ntsuas tsis pom tseeb - qhov tseem ceeb, lawv "khoov" lub teeb ntau npaum li cas.

Cov tub ntxhais muaj qhov ntsuas siab dua me ntsis dua li cov cladding. Qhov sib txawv no ua rau lub kaum ntse ntse uas lub teeb tsoo lub ciam teb ntawm cov tub ntxhais thiab cladding tsis khiav mus rau hauv lub cladding. Hloov chaw, nws cuam tshuam tag nrho rov qab rau hauv lub hauv paus. Cov txheej txheem no rov ua tsis tu ncua thaum lub teeb mem tes mus rau hauv cov fiber ntau, thaws tawm ntawm cov tub ntxhais - cladding ciam teb ntau txhiab zaus hauv ib 'meter'.

Kev zoo nkauj ntawm tag nrho cov kev xav hauv sab hauv yog nws cov kev ua tau zoo. Tsis zoo li cov iav uas nqus tau qee lub teeb nrog txhua qhov kev xav, tag nrho cov kev xav sab hauv hauv siab - zoo fiber ntau ua rau yuav luag tsis muaj lub teeb poob ntawm txhua qhov bounce. Lub teeb mem tes tuaj yeem mus txog kaum ob mais ua ntej yuav tsum tau ua kom muaj zog- qhov sib txawv ntawm cov teeb liab hluav taws xob hauv tooj liab, uas degrade ntau tshaj li ob peb puas meters.

Qhov kub thiab txias, cable dabtsi yog khoov, thiab fiber ntau zoo tag nrho cuam tshuam cov txheej txheem no. Yog tias koj khoov cov fiber ntau heev (ib qho teeb meem hu ua microbending), lub kaum sab xis ntawm lub teeb hloov pauv, thiab qee lub teeb dim. Qhov no yog vim li cas fiber optic cables tuaj nrog yam tsawg kawg nkaus khoov vojvoog specifications, thiab yog vim li cas installers yuav tsum ua raws li nruj tswj cov txheej txheem.

 

Los ntawm hluav taws xob mus rau lub teeb thiab rov qab dua

 

Kev hloov pauv ntawm hluav taws xob thiab kho qhov muag teeb liab tshwm sim ntawm cov khoom siv tshwj xeeb hu ua transceivers. Cov qauv sib cog lus no ua cov neeg txhais lus ntawm lub ntiaj teb digital ntawm cov khoos phis tawj thiab lub ntiaj teb kho qhov muag ntawm fiber ntau tes hauj lwm.

Thaum kawg, cov khoom siv semiconductor tsim lub teeb pulses. Rau qhov luv luv thiab qis dua, lub teeb -emitting diodes (LEDs) ua haujlwm txaus. Lawv ntseeg tau, pheej yig, thiab muaj lub neej ntev. Txawm li cas los xij, feem ntau niaj hnub kho qhov muag cov ntaub ntawv kis tau tus mob siv laser diodes xwb. Cov khoom siv no tsim cov teeb pom kev zoo, sib koom ua ke teeb pom kev zoo uas ob peb ua tau zoo rau hauv cov cores fiber ntau thiab ua kom muaj kev hloov pauv sai.

Laser diodes feem ntau ua haujlwm ntawm qhov tshwj xeeb wavelengths optimized rau fiber ntau kis tau tus mob: 850 nanometers luv luv-ntau hom fiber ntau sib txuas, thiab 1,310 lossis 1,550 nanometers ntev -ntaus ib qho- hom fiber ntau. Cov infrared wavelengths tsis pom rau tib neeg lub qhov muag tab sis propagate los ntawm fiber ntau nrog tsawg nqus.

Lub transmitter tsis tsuas yog flash lub laser rau thiab tawm. Cov tshuab niaj hnub no siv cov txheej txheem kev hloov kho tshiab uas siv ntau yam khoom hauv ib lub pulse los ntawm kev sib txawv ntawm lub teeb, theem, lossis polarization. Advanced hom xws li quadrature amplitude modulation tuaj yeem ua tiav spectral efficiency ntawm 6-8 ntsis ib hertz ntawm bandwidth- ua ntau tshaj li qhov yooj yim on-off keying.

Thaum kawg tau txais, photodetectors saib xyuas lub teeb tuaj thiab hloov mus rau hluav taws xob tam sim no. Cov sensors no, feem ntau yog photodiodes lossis avalanche photodiodes, teb rau ib tus neeg photons nrog rhiab heev. Cov teeb liab hluav taws xob lawv tsim tsom iav qhov qauv teeb pom kev zoo: siab tam sim no thaum lub teeb tam sim no, qis tam sim no thaum tsis tuaj. Cov teeb liab ua tiav tom qab ntawd rov tsim kho qhov qub binary cov ntaub ntawv ntws.

Tag nrho cov txheej txheem hloov dua siab tshiab- hluav taws xob mus rau qhov muag pom, kis tau los ntawm fiber ntau, kho qhov muag rov qab mus rau hluav taws xob- tshwm sim nrog cov nqi yuam kev tsawg heev. Zoo-tsim kho qhov muag tshuab ua tiav qhov yuam kev me ntsis hauv qab ib qho kev ua yuam kev ntawm plaub npaug ntawm cov khoom xa mus, zoo dua li cov tshuab hluav taws xob feem ntau.

 

Tib-Mod vs. Multi-Mode Kis

 

Tsis yog txhua lub tshuab fiber ntau optic ua haujlwm zoo ib yam. Kev lag luam siv ob hom fiber ntau sib txawv, txhua qhov ua tau zoo rau cov kev siv tshwj xeeb thiab kev ncua deb.

Multi- hom fiber ntau muaj qhov loj me me ntawm 50 lossis 62.5 microns. Qhov loj me no tso cai rau lub teeb mus los ntawm ntau txoj hauv kev (hom) ib txhij los ntawm fiber ntau. Txhua txoj kev muaj qhov ntev sib txawv me ntsis, yog li lub teeb pulses mus txawv tebchaws tuaj txog ntawm lub sijhawm sib txawv me ntsis -ib qho teebmeem hu ua modal dispersion. Qhov kev sib kis ntawm cov mem tes no txwv kev sib kis deb thiab ceev. Ntau- hom fiber ntau feem ntau ua haujlwm txuas mus txog 500 meters rau siab- cov ntawv thov ceev, txawm hais tias nws tuaj yeem txuas ntxiv ntawm cov ntaub ntawv qis dua.

Qhov zoo ntawm ntau- hom fiber ntau yog nyob rau hauv nws qhov kam rau ua thiab tus nqi. Cov tub ntxhais loj dua ua kom kev sib haum xeeb yooj yim dua thaum lub sijhawm teeb tsa thiab lees txais lub teeb los ntawm qhov pheej yig dua LED qhov chaw. Nws yog qhov kev xaiv zoo tshaj plaws rau cov ntaub ntawv chaw sib cuam tshuam, kev sib txuas hauv tsev kawm ntawv, thiab tsim cov pob txha rov qab uas qhov kev ncua deb nyob nruab nrab.

Tib - hom fiber ntau nqaim lub hauv paus rau tsuas yog 8 -10 microns- me me nws tso cai rau ib txoj hauv kev xwb. Qhov no tshem tawm modal dispersion nkaus. Lub teeb pulses tuav lawv cov duab nyob rau qhov deb heev, txwv feem ntau los ntawm cov khoom siv fiber ntau nqus thiab wavelength- nyob ntawm cov teebmeem cuam tshuam. Nrog rau lub sij hawm amplification, ib hom kab ke niaj hnub ncua ntau pua mais.

Tib - hom fiber ntau xav tau qhov tseeb dua. Cov tub ntxhais me me yuav tsum muaj kev sib raug zoo thiab laser qhov chaw rau kev sib txuas zoo. Cov cuab yeej siv tau nce siab dua, tab sis rau ntev - kev sib txuas lus hauv kev sib txuas lus, cov kab hauv qab hiav txwv, thiab cov chaw hauv nroog loj, ib qho - hom fiber ntau yog tib txoj kev xaiv.

Cov kev tshawb fawb tsis ntev los no kuj tau tshawb nrhiav ob peb - hom fibers thiab ntau - cov tub ntxhais fibers kom muaj peev xwm ntxiv. Ob peb- hom fibers txhawb ntau hom sib txawv (ntau dua li ntau pua), tso cai rau ntau cov ntaub ntawv ywj pheej hauv ib qho fiber ntau. Multi- tub ntxhais fibers ntim ob peb cores rau hauv ib qho cladding. Ob txoj hauv kev tsom mus rau qhov muaj peev xwm tshaj li qhov sib faib wavelength multiplexing ib leeg tuaj yeem ua tiav.

 

Wavelength Division Multiplexing

 

Lub zog tiag tiag ntawm cov ntaub ntawv kho qhov muag kis tau tshwm sim thaum lub tshuab xa ntau lub teeb liab ib txhij los ntawm tib lub fiber ntau. Wavelength division multiplexing (WDM) ua tiav qhov no los ntawm kev siv cov xim sib txawv ntawm lub teeb raws li kev sib txuas lus ywj pheej.

Xav txog WDM li tsim ntau txoj kev pom tsis pom hauv ib lub fiber ntau. Txhua lub wavelength (xim) nqa nws tus kheej cov ntaub ntawv kwj, thiab vim hais tias sib txawv wavelengths tsis cuam tshuam rau ib leeg, ntau los yog ntau pua tuaj yeem nyob hauv tib lub fiber ntau. Lub kaw lus WDM tuaj yeem sib kis ntawm 1,530 nanometers, 1,531 nanometers, 1,532 nanometers, thiab lwm yam -txhua lub wavelength sib cais los ntawm ib feem ntawm ib nanometer tseem ua haujlwm raws li kev ywj pheej channel.

Dense wavelength division multiplexing (DWDM) thawb lub tswvyim no mus rau qhov kawg. Niaj hnub nimno DWDM systems ntim cov channel nrog qhov nrug nqaim li 25 GHz (kwv yees li 0.2 nanometers). Cov ntaub ntawv- teeb tsa 402 Tb/s kis tau tus mob ua tiav xyoo 2024 tau siv 1,097 cov kab sib cais wavelength sib nrug los ntawm 1,410 txog 1,623 nanometers-qhov tseem ceeb ntawm tag nrho qis- poob qhov rais ntawm tus qauv silica fiber.

Kev ua haujlwm WDM yuav tsum muaj cov khoom siv meej. Wavelength multiplexers muab sib txawv laser outputs rau hauv cov teeb liab sib txuas rau kev sib kis. Thaum qhov kawg tau txais, demultiplexers cais cov teeb liab sib xyaw rov qab rau hauv ib tus neeg wavelengths. Thoob plaws hauv lub network, optical amplifiers txhawb tag nrho cov wavelengths ib txhij tsis hloov lub teeb rau hluav taws xob.

Kev lag luam hauv kev sib txuas lus faib cov khoom siv kho qhov muag rau hauv cov qauv qauv: C-band (1,530-}1,565 nm) pom kev siv ntau tshaj plaws vim kev ua haujlwm zoo tshaj plaws, thaum cov tshuab tshiab tau nce ntxiv rau L-band (1,565-}1,625 nm-60) thiab txawm tias E-band (1,360-1,460 nm) kom nthuav dav.

 

 

Overcoming Distance Limitations

 

Lub teeb pulses tsis taug kev mus ib txhis tsis hloov pauv. Txawm tias nyob rau hauv ultra- iav ntshiab, photons qee zaus tau nqus los ntawm silicon- cov pa oxygen bonds los yog tawg los ntawm microscopic imperfections. Lub zog hluav taws xob poob qis tshaj tawm nrog kev ncua deb -ib qho tshwm sim hu ua attenuation ntsuas hauv decibels ib mais.

Tus qauv ib zaug - hom fiber ntau nthuav tawm nws qhov qis tshaj plaws attenuation nyob ib ncig ntawm 1,550 nanometers: kwv yees li 0.2 dB ib kilometer. Qhov no txhais tau tias tom qab 100 kilometers, lub teeb liab poob 95% ntawm nws lub zog. Tom qab 300 km, tsawg dua 0.1% tseem nyob. Yog tsis muaj kev cuam tshuam, lub teeb liab dhau los ua tsis muaj zog rau cov neeg txais kev pom zoo kom ntseeg tau.

Tau ntau xyoo lawm, qhov no yuav tsum tau regenerators: cov khoom siv uas hloov cov teeb liab kho qhov muag rau hauv daim ntawv hluav taws xob, ua kom nrov nrov thiab kho lawv, tom qab ntawd hloov mus rau lub teeb. Cov opto-kev hloov pauv hluav taws xob no tau tsim muaj kev tsis sib haum xeeb thiab ntxiv qhov nyuaj. Lub invention ntawm erbium-doped fiber amplifiers nyob rau hauv lub xyoo 1980s tau hloov mus ntev -kev sib txuas lus kho qhov muag.

Erbium-doped fiber ntau amplifiers (EDFAs) ncaj qha ua kom pom cov teeb liab tsis muaj hluav taws xob hloov pauv. Ib ntu luv ntawm fiber ntau doped nrog erbium atoms tau "tso" nrog lub teeb laser hnyav ntawm ib lub wavelength tshwj xeeb. Qhov no ua rau lub zog ntawm erbium atoms, uas tom qab ntawd nthuav tawm cov teeb liab wavelengths los ntawm kev txhawb nqa emission-tseem ceeb yog fiber ntau-raws li laser uas txhawb nqa cov ntaub ntawv- nqa cov teeb liab thaum tseem pob tshab rau cov ntaub ntawv lawv muaj.

EDFAs ua haujlwm thoob plaws C-band thiab L-band wavelength ranges, ua rau lawv zoo tagnrho rau WDM systems. Ib qho EDFA ib txhij ua kom muaj zog ntau ntawm cov kab hluav taws xob wavelength. Muab tso rau txhua 80-100 kis lus mev raws li submarine cables thiab kev sib txuas hauv av, lawv ua kom muaj kev sib txuas lus thoob ntiaj teb cov ntaub ntawv kho qhov muag.

Tshaj li amplification, dispersion poses lwm qhov kev sib tw nyob deb. Qhov sib txawv wavelengths taug kev ntawm qhov sib txawv me ntsis los ntawm fiber ntau -chromatic dispersion- ua rau pulses sib kis thiab sib tshooj. Dispersion them nyiaj modules lossis sophisticated digital signal processing ntawm receivers tuaj yeem kho qhov teebmeem no, tab sis nws tseem yog ib qho tseem ceeb ntawm kev txiav txim siab rau siab -ceev, ntev - deb systems.

 

Tiag -Kev siv ntiaj teb thiab kev ua tau zoo

 

Optical data transmission forms invisible infrastructure of modern digital life. Nws daim ntawv thov ncua sij hawm los ntawm centimeters mus rau txhiab kilometers.

Ntawm qhov tsawg tshaj plaws, kev sib txuas kho qhov muag tau tshwm sim hauv cov chaw zov me nyuam cov ntaub ntawv thiab txawm nyob rau hauv ib tus neeg servers. Cov kab txuas luv luv hloov cov tooj liab cables ntawm racks, muab ntau dua ntom ntom thiab qis zog noj. Qee qhov kev txiav- ntug tshuab tam sim no siv silicon photonics coj qhov muag pom kev ncaj qha rau cov chips processor, txo qis latency thiab siv zog siv hauv AI kev cob qhia pawg.

Cov chaw zov me nyuam cov ntaub ntawv sawv cev rau qhov nrawm tshaj plaws - ntu ntawm kev xa khoom siv kho qhov muag. Cov chaw loj loj ua haujlwm los ntawm cov chaw muab kev pabcuam huab thiab cov tuam txhab hauv internet ua haujlwm petabytes txhua hnub los ntawm kev hloov kho qhov muag. Qhov kev xav tau ntau ntxiv ntawm kev txawj ntse txawj ntse-tshwj xeeb tshaj yog kev cob qhia cov qauv lus loj- tau nrawm rau kev siv 400 Gbps thiab 800 Gbps coherent optical links. Los ntawm 2025, 1.6 Tbps pluggable transceivers yuav tsum nkag mus rau ntau lawm.

Metropolitan thiab regional networks txuas cov nroog thiab cov lag luam nrog cov nplhaib ntawm fiber ntau. Cov tes hauj lwm no nce siv daim phiaj hloov tau yooj yim WDM uas tuaj yeem faib cov bandwidth raws li kev xav tau hloov pauv. Ib lub tuam txhab nyiaj txiag tam sim ntawd yuav xav tau 400 Gbps rau lub sijhawm luv luv, tom qab ntawd ntsuas rov qab - cov tshuab kho qhov muag tuaj yeem ua raws li qhov elasticity zoo dua li cov khoom siv hluav taws xob ruaj khov.

Ntev -kev sib txuas sib txuas txuas ntxiv mus thiab dej hiav txwv. Submarine cables nqa ntau dua 95% ntawm kev sib txuas hauv internet. Cov kab hluav taws xob niaj hnub siv tib - hom fiber ntau nrog DWDM systems ua tiav tag nrho cov peev txheej tshaj 10 Pbps ib khub fiber ntau. Cov kab hluav taws xob tshiab tshaj plaws suav nrog ntau tus khub fiber ntau-12 lossis ntau dua-kev muab rov ua dua thiab muaj peev xwm sib sau loj heev. Cable systems xws li Grace Hopper (txuas US, UK, thiab Spain) los yog Pacific Light Cable Network piv txwv li tam sim no muaj peev xwm: pua pua ntawm terabits ib ob hla ntau txhiab kilometers.

Dawb -chaw optical kev sib txuas lus muaj lwm daim ntawv thov sau npe. Tsis yog kev kaw lub teeb hauv fiber ntau, cov tshuab no kis tau los ntawm huab cua lossis lub tshuab nqus tsev. Luv-ntau yam pub dawb- qhov chaw kho qhov muag txuas tuaj yeem muab siab -kev sib txuas wireless ceev ntawm cov tsev uas tso fiber ntau tsis zoo. NASA tau ua kom pom kev sib sib zog nqus-chaw kho qhov muag qhov chaw, xa cov ntaub ntawv los ntawm lub dav hlau mus txog 200 lab mais deb- ua pov thawj kev xa xov hluav taws xob ua haujlwm txawm tias nyob hauv lub tshuab nqus tsev.

 

Qhov zoo tshaj ntawm cov txheej txheem

 

Qhov tseem ceeb ntawm cov ntaub ntawv kho qhov muag kis tau los ntawm ntau qhov zoo ntawm cov tshuab hluav taws xob.

Bandwidth muaj peev xwm tshaj ib qho kev sib tw technology. Thaum qeb 6 tooj liab Ethernet cable saum toj kawg nkaus nyob ib ncig ntawm 10 Gbps tshaj 50 meters, ib qho - hom fiber ntau niaj hnub nqa terabits ib ob ntawm qhov deb heev. Qhov no tsis yog kev txhim kho ntxiv - nws yog qhov kev txiav txim loj dua.

Electromagnetic tiv thaiv ua pov thawj tseem ceeb hauv ntau qhov chaw. Cov teeb liab hluav taws xob hauv tooj liab tsim cov chaw sib nqus thiab tuaj yeem cuam tshuam los ntawm cov motors, transformers, xov tooj cua transmitters, thiab lwm qhov chaw. Cov teeb liab kho qhov muag, ua photons ntau dua li cov hluav taws xob, nyob twj ywm tsis muaj zog tiv thaiv electromagnetic cuam tshuam. Koj tuaj yeem khiav fiber ntau nrog rau siab - cov kab hluav taws xob hluav taws xob, los ntawm cov chaw tsim hluav taws xob tsis zoo, lossis hauv cov chaw tiv thaiv hluav taws xob tsis muaj teeb liab degradation.

Kev ruaj ntseg tau txais txiaj ntsig los ntawm physics. Tapping ib qho hluav taws xob cable yog qhov yooj yim heev -koj tuaj yeem ntes hluav taws xob xaim yam tsis tau kov cov hlau. Kev nkag mus rau cov ntaub ntawv nyob rau hauv ib qho kev kho qhov muag fiber ntau yuav tsum tau tawg mus rau hauv lub cev cable, uas feem ntau ua rau lub teeb liab tsis pom. Rau kev sib txuas lus thiab kev sib txuas lus nyiaj txiag, qhov txiaj ntsig kev nyab xeeb no nqa qhov hnyav hnyav.

Qhov loj thiab qhov hnyav hnyav dua li qhov koj xav tau. Fiber cables yog qhov me me thiab sib zog dua li qhov sib npaug - muaj peev xwm tooj liab cables. Ib qho fiber ntau me dua li tib neeg cov plaub hau tuaj yeem nqa cov ntaub ntawv ntau dua li cov ntaub ntawv tuab ntawm tooj liab. Rau cov ntawv thov xws li dav hlau, dav hlau, lossis cov ntaub ntawv chaw nyob ib puag ncig, qhov sib txawv no yog qhov tseem ceeb.

Kev muaj peev xwm nyob deb tshem tawm cov repeaters. Thaum cov teeb liab hluav taws xob xav tau kev tsim dua tshiab txhua ob peb puas meters, cov teeb liab kho qhov muag mus txog kaum lossis ntau pua mais ua ntej amplification. Qhov no txo ​​cov nqi khoom siv, kev siv hluav taws xob, thiab kev saib xyuas tsis yooj yim -tshwj xeeb tshaj yog muaj txiaj ntsig rau cov cables submarine uas nkag mus rau cov cuab yeej yog qhov nyuaj thiab kim heev.

Lub neej ntev thiab kev ntseeg siab feem ntau nyiam fiber ntau. Kev txhim kho fiber ntau zoo dhau xyoo lawm nrog kev saib xyuas tsawg. Lub iav nws tus kheej tsis corrode zoo li tooj liab, thiab tiv thaiv txheej tiv thaiv nws los ntawm ib puag ncig degradation. Ntau lub tshuab fiber ntau tau teeb tsa hauv xyoo 1990s tseem ua haujlwm zoo kawg nkaus, txawm tias muaj tsheb khiav ntau dua li qhov xav tau thaum xub thawj.

 

Cov kev txwv uas siv tau

 

Txawm hais tias nws qhov zoo, kev xa cov ntaub ntawv kho qhov muag los nrog cov kev txwv tiag tiag thiab cov teeb meem.

Installation xav tau kev saib xyuas thiab kev txawj ntse. Cov iav fibers tawg yog khoov heev los yog ntxhov siab thaum lub sijhawm teeb tsa. Fusion splicing-tus txheej txheem ntawm kev koom nrog ob lub fibers mus tas li- yuav tsum tau siv cov cuab yeej kim thiab cov kws tshaj lij. Cov khoom sib txuas yuav tsum tau ceev kom huv si; cov plua plav plua plav ntawm lub ntsej muag txuas txuas tuaj yeem thaiv cov tub ntxhais microscopic thiab cuam tshuam kev sib kis.

Cov qauv nqi tsis zoo rau cov tshuab kho qhov muag hauv qee qhov xwm txheej. Thaum cov nqi fiber ntau tau poob qis, cov transceivers tseem kim, tshwj xeeb tshaj yog rau cov tshuab kho qhov muag sib txuas khiav ntawm 400 Gbps lossis siab dua. Rau kev sib txuas luv luv nqa cov ntaub ntawv me me, tooj liab tseem pheej yig dua. Qhov no yog vim li cas feem ntau cov khoos phis tawj desktop tseem txuas mus rau cov tes hauj lwm ntawm tooj liab Ethernet, txawm hais tias kev tshaj lij ntawm fiber ntau.

Lub cev fragility ua rau muaj kev pheej hmoo tiag. Fiber cables tuaj yeem muaj sia nyob faus thiab kev teeb tsa sab nraum zoov yog tias tsim tau zoo nrog kev tiv thaiv sheathing, tab sis cov iav fiber ntau nws tus kheej tawg nyob rau hauv lub zog ntau dhau los yog khoov ntse. Hauv qee qhov chaw-tshwj xeeb yog chaw tsim khoom nrog cov tshuab hnyav- xyuas kom muaj kev tiv thaiv fiber ntau yuav tsum tau ua tib zoo npaj.

Kev sim thiab daws teeb meem kho qhov muag yuav tsum muaj cov cuab yeej tshwj xeeb. Lub sij hawm kho qhov muag-domain reflectometers (OTDRs), kho qhov muag fais fab ntsuas, thiab qhov muag pom qhov tsis pom kev tsis tuaj yeem pheej yig. Cov kws tshaj lij xav tau kev cob qhia los txhais cov txiaj ntsig kev xeem thiab tshuaj xyuas cov teeb meem. Cov tshuab tooj liab, los ntawm qhov sib txawv, feem ntau tuaj yeem sim nrog cov cuab yeej yooj yim dua, tsis tshua kim.

Wavelength -nyob ntawm qhov cuam tshuam tsim kev nyuaj. Qhov sib txawv wavelengths coj txawv ntawm fiber ntau, txwv WDM system tsim. Kev hloov pauv kub cuam tshuam rau lub wavelength me ntsis, yuav tsum muaj kev tswj lub wavelength nyob rau hauv tuab WDM systems. Cov teeb meem no, thaum daws tau, ntxiv tus nqi thiab qhov nyuaj piv rau ib qho yooj yim dua - wavelength systems.

 

Tsis ntev los no kev tawg thiab kev taw qhia yav tom ntej

 

Kev ua haujlwm txuas ntxiv mus sai, tshwj xeeb tshaj yog hauv kev ua kom muaj peev xwm fiber ntau thiab txhim kho kev ua haujlwm. Ntau qhov kev txhim kho xyoo 2024 qhia txog cov qauv tam sim no.

Qhov chaw - faib multiplexing tau txais traction raws li tus pem hauv ntej rau kev scaling. Cov kws tshawb fawb tab tom tsim ntau- cov tub ntxhais fibers nrog ntau lub cores ywj siab nyob rau hauv ib qho cladding, thiab ob peb - hom fibers uas txhawb kev tswj spatial hom. Ua ke nrog wavelength multiplexing, cov txheej txheem no tuaj yeem ua kom muaj peev xwm fiber ntau los ntawm lwm qhov kev txiav txim siab.

Coherent transceivers ua kom shrinking thaum tuav ceev dua. Kev lag luam tau txav los ntawm khib- mounted coherent systems rau pluggable modules me dua ib tug USB stick, txhawb 400 Gbps los yog 800 Gbps. Qhov no miniaturization txo hwj chim noj thiab ua kom denser network architectures.

Advanced modulation formats nyem ntau cov khoom ib photon. Probabilistic constellation shaping kho cov teeb liab encoding raws li cov xwm txheej ntawm cov channel, mus txog qhov muaj peev xwm theoretical txwv. Tshuab kawm algorithms optimize kis tsis tau nyob rau hauv tiag -lub sij hawm, adapting rau hloov fiber ntau tej yam kev mob.

Silicon photonics cog lus tias yuav muab cov khoom siv kho qhov muag ncaj qha rau ntawm silicon chips siv cov txheej txheem semiconductor manufacturing. Qhov no tuaj yeem txo cov nqi rau optical transceivers thaum ua kom muaj kev sib raug zoo ntawm kev suav thiab kev sib tham kho qhov muag.

Quantum tseem ceeb faib tshaj optical fibers thaum kawg yuav ruaj ntseg kev sib txuas lus tiv thaiv tej kev hem thawj yav tom ntej, nrog rau quantum computers. Thaum tseem tab tom sim, QKD cov tshuab tau pib tshwm hauv cov ntawv tshwj xeeb siab -kev nyab xeeb.

 

Cov lus nug nquag

 

Dab tsi ua rau cov ntaub ntawv kho qhov muag kis tau sai dua li tooj liab cables?

Lub teeb mus los ntawm fiber ntau ntawm kwv yees li 200,000 kilometers ib ob -ze rau nws lub tshuab nqus tsev ceev. Qhov tseem ceeb tshaj, qhov optical spectrum qhov siab zaus tso cai rau kev nkag siab cov ntaub ntawv ntau dua li qis dua - zaus hluav taws xob teeb liab. Ib qho fiber ntau tuaj yeem nqa ntau lub wavelengths ib txhij, txhua qhov kev khiav hauj lwm ntawm ntau pua gigabits ib ob, ua tiav cov peev txheej ua tsis tau nrog cov tshuab hluav taws xob.

Puas yog optical fibers puas los ntawm electromagnetic pulses?

Tsis yog. Optical fibers xa cov ntaub ntawv raws li photons, tsis yog electrons. Electromagnetic pulses uas yuav rhuav tshem cov tooj liab-raws li cov kab ke kis tsis zoo los ntawm fiber ntau. Qhov kev tiv thaiv kab mob no ua rau fiber ntau qhov kev xaiv zoo tshaj plaws rau kev ua tub rog, cov chaw nres tsheb fais fab, thiab lwm qhov chaw uas muaj hluav taws xob hem.

Fiber optic cable kav ntev npaum li cas?

Kev txhim kho fiber ntau zoo ib txwm ua haujlwm rau 25-30 xyoo lossis ntev dua. Lub iav nws tus kheej tsis degrade ntau dhau sijhawm. Feem ntau "kev hloov kho fiber ntau" hloov cov khoom siv kawg (transmitters thiab receivers) es tsis yog fiber ntau nws tus kheej, vim tias cov thev naus laus zis tshiab tuaj yeem siv cov fiber ntau uas twb muaj lawm kom ua tiav qhov nrawm dua.

Vim li cas ho tsis muaj fiber ntau optics hloov tooj liab?

Economics thiab physics ob leeg ua lub luag haujlwm. Rau luv luv (hauv qab 100 meters) nqa cov ntaub ntawv nruab nrab, tooj liab tseem pheej yig dua. Kev teeb tsa thiab cov khoom siv raug nqi nyiam tooj liab thaum tsis xav tau qhov zoo ntawm kev ua haujlwm kho qhov muag. Tsis tas li ntawd, tooj liab muab hluav taws xob hluav taws xob nrog rau cov ntaub ntawv- muaj txiaj ntsig zoo rau cov khoom siv xws li lub koob yees duab kev ruaj ntseg thiab cov ntsiab lus nkag wireless.

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Kev xa cov ntaub ntawv kho qhov muag sawv cev yog ib qho ntawm tib neeg txoj kev vam meej tshaj plaws ntawm physics rau engineering. Los ntawm kev siv lub teeb nrawm thiab zaus los encode cov ntaub ntawv, xa nws los ntawm iav purer dua li tej yam ntuj tso siv lead ua, thiab ntes tus neeg photons nyob rau hauv qhov kawg, peb tau tsim lub ntiaj teb no paj hlwb txuas ntau lab ntawm cov khoom siv. Cov thev naus laus zis txuas ntxiv mus ntxiv - cov ntaub ntawv tsis ntev los no tshaj li 400 terabits ib ob hauv ib lub fibers - tseem cov ntsiab lus tseem ceeb tseem nyob hauv cov kev tshawb pom ntau xyoo dhau los. Raws li cov ntaub ntawv xav tau loj hlob nrog kev txawj ntse, kev tshaj tawm xov xwm, thiab kev suav huab, cov tshuab kho qhov muag tsuas yog dhau los ua qhov tseem ceeb rau cov txheej txheem niaj hnub no.