Fiber Optic Attenuation (poob), Ua rau kom txo qis thiab txhim kho

Dab tsi yog fiber optic attenuation (fiber optic poob)

Fiber optic attenuation (fiber optic poob) yog hais txog qhov tshwm sim uas qhov kev siv ntawm lub teeb maj mam txo qis vim muaj ntau yam raws li qhov sib kis tau nce ntxiv thaum lub teeb liab optical kis tau rau hauv fiber ntau optical.
Attenuation yog ib qho tseem ceeb kis tus yam ntxwv ntawm optical fiber.
Feem ntau cov ntsiab lus fiber optic attenuation thiab fiber optic poob yog siv interchangeably.

 

Attenuation (lossis) yam

Peb paub tias kom ua tiav cov txheej txheem ntawm kev sib txuas lus, ntxiv rau kev xa cov teeb liab kho qhov muag, lub teeb liab kho qhov muag ntawm qhov kawg tau txais yuav tsum muaj peev xwm txais tau zoo thiab raug demodulated.

Fiber attenuation ua rau cov teeb liab kho qhov muag maj mam poob lub zog thaum sib kis, yog li cuam tshuam rau qhov zoo thiab qhov deb ntawm lub teeb liab. Txhawm rau kom ntseeg tau tias cov teeb liab kho qhov muag kis tau zoo, qhov poob ntawm qhov muag fiber ntau yuav tsum tau txo kom ntau li ntau tau.

Peb lub hom phiaj yog kom txo qis fiber ntau optic poob, yog li qhov tsawg tsawg?

Yuav ntsuas fiber ntau attenuation (poob) li cas?

Fiber optic poob cov yam ntxwv tuaj yeem ntsuas los ntawm qhov poob (attenuation) coefficient, uas yog qhov attenuation ib chav tsev ntev ntawm fiber ntau, hauv dB / km.

= 10*log(Pin / Pout) / L

Qhov twg L yog qhov ntev ntawm fiber ntau km raws li qhov yooj yim qhov ntev chav tsev, Pin thiab Pout yog lub tswv yim thiab tso zis hluav taws xob kho qhov muag, feem.

Ib qho piv txwv.

Qhov ntev ntawm cov fiber ntau yog 100km, input optical zog ntawm cov fiber ntau yog 100mW, cov zis optical zog yog 1mW, xam cov attenuation coefficient ntawm fiber.

Nqa cov qauv: {{0}}*log(100/1) / 100, tuaj yeem tau txais fiber ntau attenuation coefficient yog: 0.2dB/km.

 

Ua rau attenuation (poob) thiab txoj hauv kev los txhim kho nws

Optical teeb liab kis tau tus mob nyob rau hauv lub optical fiber, vim yog tawg, nqus, tsis xws luag thiab lwm yam ua rau lub zog poob, ua rau attenuation.

 

Ua ntej, absorption poob

Absorption poob yog tshwm sim los ntawm fiber optic cov ntaub ntawv thiab impurities nyob rau hauv lub nqus ntawm lub teeb lub zog, lub optical zog nyob rau hauv daim ntawv ntawm tshav kub zog noj nyob rau hauv fiber, yog ib qho tseem ceeb poob nyob rau hauv lub optical fiber poob, absorption poob muaj xws li cov hauv qab no:

1, intrinsic absorption poob

Intrinsic absorption poob yog ib qho poob hauv cov khoom siv fiber ntau, yog yam tsis muaj kev zam, nws txiav txim siab qhov poob ntawm cov fiber ntau. Intrinsic absorption yog muaj nyob rau hauv cov khoom siv quartz nws tus kheej, suav nrog infrared absorption thiab ultraviolet absorption.

 

 

UV Absorption: Nyob rau hauv qhov luv wavelength ntau yam, cov electrons ntawm fiber optic cov ntaub ntawv nqus qhov teeb meem lub teeb lub zog dhia mus rau ib tug ntau zog theem, ua rau lub zog poob ntawm qhov teeb meem teeb. Kev nqus ultraviolet yog tshwm sim los ntawm electron dhia, uas muaj kev cuam tshuam rau kev sib txuas lus fiber ntau hauv thaj tsam 700 txog 1100nm wavelength.
Infrared absorption: nyob rau hauv qhov ntev wavelength ntau yam, lub teeb yoj cuam tshuam nrog fiber ntau lattice, thiab ib feem ntawm lub teeb yoj lub zog yog pauv mus rau lub lattice, uas intensifies nws vibration, yog li ua rau poob. Infrared absorption yog tshwm sim los ntawm molecular kev co, uas muaj feem xyuam rau fiber optic kev sib txuas lus nyob rau hauv lub wavelength cheeb tsam ntawm 1500-1700nm.

 

2, impurity absorption poob
Impurity absorption poob yog cov khoom siv fiber ntau muaj cov hlau, tooj liab, chromium thiab lwm yam impurity ions, hlau ions, cov ntsiab lus ntau dua, qhov ntau dua qhov poob los ntawm lawv, lawv muaj kev cuam tshuam zoo rau lub luv wavelengths, ntev wavelengths ntawm qhov cuam tshuam. tus me.
Kev siv cov khoom siv high-purity fiber optic, kev tswj nruj ntawm cov ntsiab lus ntawm cov hlau ions, tuaj yeem ua rau lawv tshwm sim los ntawm kev poob sai sai.

Lwm qhov yog OH ions, OH ions muaj kev cuam tshuam ntau dua rau kev poob ntawm fiber ntau. Nyob rau hauv lub 950nm, 1240nm, 1390nm wavelength nyob ze ntawm lub ncov absorption, mus rau 1390nm ntawm qhov nqus ntawm qhov hnyav tshaj plaws, uas feem ntau hnov ​​​​txog "dej ncov" nqus.

 

 

Thib ob, tawg tawg

Scattering poob yog vim cov khoom siv fiber ntau qhov ntom ntom tsis sib xws lossis fiber ntau waveguide cov yam ntxwv tsis xws li optical fais fab xau tawm ntawm cov tub ntxhais los ntawm kev poob.

Intrinsic scattering yog qhov tseem ceeb tshaj plaws hauv kev tawg ntawm cov khoom tawg, lub zog poob yog linearly cuam tshuam nrog lub zog ntawm kev nthuav tawm hom. Nws yog vim cov khoom atoms los yog molecules thiab cov khoom qauv ntawm inhomogeneity ntawm lub refractive index ntawm cov khoom, ua rau cov khoom tsim microscopic inhomogeneity tshwm sim los ntawm kev tawg ntawm kis lub teeb tsis. Qhov kev tawg no muaj nyob rau hauv cov khoom siv, tsis tuaj yeem raug tshem tawm, yog qhov tsawg tshaj plaws ntawm cov fiber ntau optical poob, Rayleigh scattering uas belongs rau pawg no.

 

Peb, hluav taws xob poob

Kev tawg hluav taws xob yog vim muaj qhov sib txawv ntawm cov qauv me me ntawm qhov cuam tshuam ntawm cov tub ntxhais cladding, qhov poob los ntawm cov qauv tsis sib xws ntawm cov waveguide hauv fiber ntau.

Ib feem ntawm cov hluav taws xob xa mus yuav raug hluav taws xob tawm ntawm cov tub ntxhais fiber ntau thaum cov qauv fiber ntau tsis sib xws thiab dhau los ua ib hom hluav taws xob, kom qhov poob nce.

Qhov kev poob no tuaj yeem txo qis los ntawm kev txhim kho cov cuab yeej tsim khoom.

 

Plaub, khoov poob

Bending poob yog qhov poob los ntawm kev khoov ntawm fiber ntau optic axis.

Txhua qhov muag liab qab pom fiber ntau axis rau txoj kab ncaj nraim yog hu ua dabtsi yog khoov lossis macro-bending.

Fiber dabtsi yog khoov yuav ua rau coupling ntawm cov hom nyob rau hauv lub fiber, thaum lub propagation hom ntawm lub zog ua ke mus rau hauv lub radiation hom los yog to, bending poob yuav tshwm sim. Qhov kev poob no nce exponentially raws li lub vojvoog ntawm curvature txo.

Lwm hom kev poob yog lub fiber axis los tsim ib qho random micron-level lateral displacement state rau hauv, hu ua micro-bending poob. Yog vim li cas rau micro-bending yog qhov kho qhov muag fiber ntau hauv txheej, cable, extrusion sheath, installation thiab lwm yam txheej txheem, cov fiber ntau raug rau ntau qhov sib txawv ntawm lub siab tsis sib xws los yog longitudinal stress, los yog optical fiber manufacturing vim yog txheej txheej los yog lub tsho kub expansion. coefficient ntawm optical fiber tsis zoo ib yam, thiab lwm yam tshwm sim.

Rau kev khoov poob, cov kab fiber ntau tuaj yeem siv cov kab hluav taws xob qis qis, lossis nruj me ntsis ua raws li kev lag luam tus qauv kev qhia tshwj xeeb rau cable tso, tsim nyog tswj kev khoov lub vojvoog ntawm lub fiber optic cable, kom deb li deb tau kom txo tau qhov khoov poob.

 

Peb tau tshwj xeeb hauv optical fiber cables lag luam rau ze li ntawm 10 xyoo thiab tau txais ntau tus neeg paub zoo thoob plaws ntiaj teb nrog kev koom tes ntev. Yog tias koj txaus siab rau peb cov fibers, thov hu rau kuv.

 

 

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