Kev faib tawm ntawm fiber ntau optic systems

Muaj ntau yam kev faib tawm ntawm fiber ntau opticalkev sib txuas lustshuab. Feem ntau, lawv raug cais raws li hauv qab no:

Yuav muab faib ua optical fiber analog kev sib txuas lus systems thiab optical fiber digital kev sib txuas lus systems.

Optical fiber ntau cov kev sib txuas lus digital muaj qhov zoo dua li qhov kho qhov muag fiber ntau analog kev sib txuas lus thiab tuaj yeem ua tau raws li qhov xav tau ntawm kev sib txuas lus muaj peev xwm thiab kev sib txuas lus zoo tshaj li yav dhau los. Qhov zoo ntawm optical fiber ntau digital kev sib txuas lus yog raws li hauv qab no:

Muaj zog tiv thaiv- muaj peev xwm cuam tshuam, kev sib kis tau zoo. Hauv kev sib txuas lus analog, suab nrov sib sau ua ke ntawm txoj kev teeb liab, thiab ob qho tib si sib cais tsis tau. Raws li lub sij hawm kis tau tus mob thiab kev ncua deb nce, nws yog tsis yooj yim sua kom cais lub suab nrov ntawm lub teeb liab los kho qhov qub teeb liab. Optical fiber ntau cov tshuab kev sib txuas lus siv cov khoom siv rov ua dua tshiab, uas tsis suav nrog kev ua kom nrov nrov. Ntev npaum li lub teeb liab -rau- suab nrov piv yog siab txaus, lub suab nrov tuaj yeem raug tshem tawm los ntawm ib qho chaw pib, thiab cov teeb liab qub tuaj yeem rov tsim dua.

Yuav siv sij hawm faib multiplexing nrog kev sib kis ntev. Optical fiber ntau digital kev sib txuas lus tshuab tuaj yeem siv ntau txoj hauv kev los tsim cov teeb liab kis tau tus mob, tshem tawm cov suab nrov thaum sib kis, rov kho qhov qub teeb liab, thiab txuas ntxiv qhov sib kis.

Haum rau kev sib kis ntawm ntau yam kev pabcuam nrog kev hloov pauv yooj yim. Hauv optical fiber ntau cov kev sib txuas lus digital, ntau cov ntaub ntawv xws li lub suab thiab cov duab tuaj yeem hloov mus rau hauv binary digital signals, uas tuaj yeem sib txuas cov tshuab xa mus thiab hloov tshuab los pab txhawb kev ua tiav ntawm kev pabcuam kev sib koom ua ke.

Ib qho yooj yim kom ua tiav encrypted siab -kev sib txuas lus ceev ceev. Tsuas yog cov neeg uas nkag siab txog kev sib txuas lus ntawm 密钥 (cov yuam sij) thiab cov txheej txheem kev txiav txim siab tuaj yeem ua tiav qhov kev sib txuas lus tsis pub lwm tus paub. Nws yog ib qho nyuaj rau nyiag cov ntaub ntawv tsis pub lwm tus paub uas yuav tsum tau tsim nrog cov txheej txheem encryption.

Optical fiber ntau cov kev sib txuas lus digital feem ntau yog siv cov digital circuits, uas yog ib qho yooj yim rau kev sib koom ua ke, me me, thiab cov khoom siv me me, cov qauv tsim, ua kom cov khoom muaj kev ntseeg siab thiab pab txo cov nqi.

Optical fiber ntau cov tshuab kev sib txuas lus muaj qhov tsis zoo ntawm kev ua haujlwm ntawm qhov dav dav, qhov kev siv zaus ntawm qhov system tsis siab, cov cuab yeej siv tau yooj yim, thiab tus nqi kuj tseem siab.

Dhau li ntawm qhov nqaim bandwidth, fiber optic analog kev sib txuas lus tseem muaj qhov zoo xws li kev sib txuas lus yooj yim, tsis tas yuav analog -rau- digital lossis digital- rau -analog hloov dua siab tshiab, thiab qis dua tus nqi. Fiber optic analog kev sib txuas lus tshuab feem ntau yog siv rau luv- kev sib txuas lus nyob deb, thaum fiber optic digital kev sib txuas lus feem ntau yog siv rau kev sib txuas lus ntev -.

Classification of fiber optic communication systems

Yuav muab faib ua luv wavelength multimode optical fiber kev sib txuas lus systems thiab ntev wavelength optical fiber kev sib txuas lus systems.

Luv wavelength multimode optical fiber kev sib txuas lus tshuab feem ntau ua haujlwm ntawm wavelengths ib ncig ntawm 0.85μm, nrog rau kev sib txuas lus qis dua 34Mbit / s thiab repeater nrug hauv 10km.

Ntev wavelength optical fiber kev sib txuas lus tshuab tuaj yeem muab faib ua peb hom hauv qab no:

1.31μm multimode optical fiber kev sib txuas lus system: Kev khiav hauj lwm wavelength nyob ib ncig ntawm 1.31μm, kev sib txuas lus ntawm 34Mbit / s thiab 140Mbit / s, repeater nrug nyob ib ncig ntawm 20km.

1.31μm ib leeg- hom kev sib txuas lus fiber ntau optical: Kev ua haujlwm wavelength nyob ib ncig ntawm 1.31μm, kev sib txuas lus ntawm 140Mbit / s thiab 565Mbit / s, repeater nrug ntawm 30-50km (140Mbit / s).

1.55μm ib leeg- hom kev sib txuas lus fiber ntau optical: Kev khiav hauj lwm wavelength nyob ib ncig ntawm 1.55μm, kev sib txuas lus tus nqi siab tshaj 565Mbit / s, repeater nrug nyob ib ncig ntawm 70km.

Yuav muab faib ua Plesiochronous Digital Hierarchy (PDH) systems thiab Synchronous Digital Hierarchy (SDH) systems.

Loj - muaj peev xwm optical fiber ntau kis tau tus mob tam sim no siv lub sij hawm Division Multiplexing (TDM) technology. Multiplexing tau muab faib ua ob peb theem, ua rau peb txoj kev sib kis: Plesiochronous Digital Hierarchy (PDH) system thiab Synchronous Digital Hierarchy (SDH) system.

Hauv PDH systems, tus nqi me ntsis ntawm txhua qib tsis tuaj yeem ncaj qha mus rau lawv tus qauv qhov tseem ceeb thiab muaj kev zam rau, uas yog qhov txawv txav. Feem ntau, txoj kev pom zoo yog siv los ua kom tiav quasi-synchronous multiplexing, nrog rau cov nqi sib kis feem ntau qis dua 565Mbit / s.

SDH systems tsis yog tsuas yog haum rau taw tes - mus rau - taw tes kis tau tus mob tab sis kuj tsim nyog rau kev sib txuas lus network ntawm ntau lub ntsiab lus. Tam sim no, cov cuab yeej siv SDH series tuaj yeem ua tiav ib qho - wavelength kev sib txuas lus ntawm 2.5Gbit / s thiab 10Gbit / s.

Yuav muab faib ua peb hom hauv qab no:

Tsawg-kev sib txuas lus fiber ntau ceev: Hom no muaj kev sib kis ntawm 2Mbit/s thiab 8Mbit/s.

Nruab nrab-kev sib txuas lus fiber ntau ceev: Hom no muaj kev sib kis ntawm 34Mbit/s thiab 140Mbit/s.

Siab -kev sib txuas lus fiber ntau ceev: Hom no muaj cov kis tau tus mob siab dua 565Mbit/s.

Yuav muab faib ua ob hom hauv qab no:

Direct intensity modulation optical fiber kev sib txuas lus system: Cov teeb liab hluav taws xob digital kom xa mus yog ncaj qha hloov kho hauv lub teeb -emitting txheej txheem ntawm lub teeb qhov chaw, los yog hu ua internal modulation optical fiber kev sib txuas lus system. Cov txheej txheem no muaj cov cuab yeej yooj yim, tus nqi qis dua, thiab kev ua haujlwm siab dua, tab sis nws yuav nthuav dav cov spectrum thiab cuam tshuam rau kev txhim kho tus nqi.

Indirect modulation optical fiber kev sib txuas lus system: Tom qab lub teeb qhov chaw emits lub teeb, ib tug modulator yog ntxiv rau lub teeb tso zis txoj kev rau modulation, kuj hu ua lwm modulation optical fiber kev sib txuas lus system. Cov kab ke no muaj kev cuam tshuam me ntsis ntawm cov kab teeb pom kev zoo thiab tsim nyog rau kev sib txuas lus siab -.