Kho qhov muag attenuationtseem yog ib qho ntawm qhov tsis tshua zoo nkauj tab sis tseem ceeb heev ua haujlwm hauv fiber ntau optic systems. Thaum cov neeg tau txais kev nkag siab zoo yuav ua rau muaj kev pheej hmoo siab tshaj - lossis thaum txuas cov peev nyiaj siv hluav taws xob xav tau kev ntsuas qhov tseeb -attenuators nkag mus. Cov kev sib cais tseem ceeb ntawm kev sib txawv ntawm qhov tsis zoo thiab kev ua haujlwm muaj kev cuam tshuam txog kev lag luam sib sib zog nqus- tawm ntawm qhov tsim cov kev txiav txim siab tsim network thoob plaws hauv xov tooj, datacenter, thiab cov chaw sim.
Txoj Kev Passive: Simplicity li Strength
Passive attenuators ua haujlwm yam tsis muaj hluav taws xob. Tag nrho nres. Qhov no ib tug yam ntxwv cascades mus rau hauv yuav luag txhua lwm yam txog lawv.
Lub physics ntawm no yog ncaj nraim. Koj nyob nraum absorbing photons (doped iav los yog hlau- ion lim), tsim kom muaj qhov sib txawv ntawm cov fiber ntau endfaces, los yog txhob txwm misaligning txoj kev kho qhov muag. Gap- hom attenuators qhia tau qhov kev sib cais tswj hwm- lub teeb diverges hla qhov chaw ntawd, thiab tsuas yog ib feem ntawm cov khub niam txiv rov qab mus rau qhov tau txais fiber ntau. Doped variants ua haujlwm sib txawv; ions embedded nyob rau hauv lub iav matrix hloov kho qhov muag lub zog rau cua sov. Tsis yog ob txoj hauv kev yuav tsum muaj kev cuam tshuam sab nraud ib zaug ntsia.
Tsau attenuators dominate qhov chaw xa tawm. Tus nqi 10dB inline attenuator tej zaum kaum tsib duas las, txhim kho hauv vib nas this, thiab yuav ua rau cov khoom siv nws txuas. Cov txiaj ntsig zoo sib xws-3dB, 5dB, 7dB, 10dB, 15dB, 20dB-npog cov xwm txheej feem ntau. Connector styles tsom rau kev lag luam dav dav: LC thiab SC rau kev teeb tsa niaj hnub, FC rau cov cuab yeej cuab tam thiab kev sim teeb tsa, qee zaus APC hloov pauv thaum rov qab poob teeb meem.
Hloov kho qhov muag attenuators (VOAs) nyob rau hauv daim ntawv passive siv kho qhov muag. Tig lub dial, hloov qhov nruab nrab- lim lim, hloov qhov sib txawv. Cov no khiav nyob qhov twg los ntawm $ 50 mus rau ob peb puas duas las nyob ntawm attenuation ntau thiab precision. Qhov zoo tuav ± 0.5dB qhov tseeb. Cov pheej yig... tsis txhob.
Kub stability txawv wildly ntawm manufacturers. Cov ntawv tshwj xeeb yuav thov 0.02dB / degree, tab sis kuv tau pom cov chav nyob drift ntau dua nyob rau sab nraum zoov cov ntaub ntawv thaum lub caij ntuj sov. Qhov sib txawv- hom qauv tsim muaj qhov kub thiab txias ntau dua - ruaj khov dua li kev nqus- raws li qhov no, txawm tias qhov no tsis muaj tseeb.
Rov qab poob tau raug saib xyuas kom txog thaum nws ua teeb meem. Standard UPC tiav muab rau koj tej zaum 50dB rov poob. APC thawb dhau 60dB. Rau DWDM systems lossis analog video txuas, qhov sib txawv no tseem ceeb heev. Rau qhov yooj yim ethernet kev twb kev txuas, tej zaum tsis.
Active Attenuation: Thaum Networks Yuav Tsum Xav
Active VOAs sawv cev rau lub hauv paus sib txawv engineering lub tswv yim. Cov khoom siv no hloov kho lub zog hluav taws xob hauv hluav taws xob, ua kom muaj kev tswj xyuas chaw taws teeb, cov lus qhia tsis siv neeg lub voj voog, thiab kev koom ua ke nrog kev tswj hwm lub network.
Technology toj roob hauv pes ntawm no fragments considerably:
MEMS-raws li VOAssiv cov iav microscopic-feem ntau silicon- uas qaij nyob rau hauv electrostatic quab yuam. Hloov lub kaum sab xis ntawm daim iav kho qhov teeb pom kev zoo ntawm cov tswv yim thiab cov zis fibers. Teb cov sij hawm hover ib ncig 1-10 milliseconds. Cov ntawv thov xov tooj no tseem ceeb tshaj qhov kev ntseeg siab thiab cov kev xav tau ceev tsis yog qhov kawg.
Cov kua siv lead ua kua attenuatorspolarize lub teeb los, tom qab ntawd tig lub xeev polarization los ntawm qhov sib txawv ntawm qhov sib txawv ntawm LC ntawm tes. Ib tug downstream polarizer thaiv ntau los yog tsawg lub teeb nyob ntawm kev taw qhia. qeeb dua MEMS-10 mus rau 100 milliseconds ib txwm-tab sis mechanically yooj yim dua. Tsis muaj qhov txav txav los hnav.
Thermo-optic designsexploit refractive index hloov nrog kub. Tshav kub ib ntu waveguide, hloov hom kev sib txuas, kho attenuation. Cov no sib xyaw ua ke zoo nkauj rau hauv cov phiaj xwm hluav taws xob hluav taws xob (PLCs) rau kev cog lus ntau -channel kev daws teeb meem.
Electro{0}}optic modulatorsraws li lithium niobate tuaj yeem ua tiav sub-microsecond teb. Pheej yig thiab muaj zog- tshaib plab, tab sis tsis muaj dab tsi ntxiv kov lawv kom ceev.
Kuv tau siv sijhawm ntau nrog MEMS units los ntawm ntau tus neeg muag khoom. Qhov kev ua tau zoo sib txawv ntawm 400moduleanda400moduleanda1,200 ib qho feem ntau los tswj cov khoom siv hluav taws xob ntau dua li lub tshuab kho qhov muag nws tus kheej. Zoo dua DACs, nruj dua cov tswv yim loops, ntau sophisticated kub them algorithms. Cov chav kim kim tuav ± 0.1dB qhov tseeb thoob plaws lawv cov haujlwm ua haujlwm; kev xaiv peev nyiaj yuav tswj tau ± 0.3dB rau hnub zoo.
Qhov twg qhov teeb meem no xyaum
DWDM systems nthuav tawm cov ntaub ntawv siv meej tshaj plaws rau kev ua kom muaj zog. Plaub caug, yim caum, cuaj caum- rau lub wavelength channel propagating ib txhij-txhua tus yuav tsum tau mus txog ntawm lub receiver nrog roughly sib npaug zog. Kev tsim cov kev kam rau siab hauv cov khoom siv laser, me ntsis kev hloov pauv hauv fiber ntau poob hla lub wavelengths, nce qaij hauv EDFAs... txhua yam sib koom ua ke rau channel - mus rau -channel zog sib txawv. VOAs ntawm ROADM nodes dynamically sib npaug qhov no.
Cov txheej txheem tswj tau sophisticated. Optical channel saib ntsuas ib -wavelength hwj chim theem; uas cov ntaub ntawv pub rau hauv algorithms txiav txim siab VOA setpoints; lub kaw lus tsis tu ncua kho raws li cov qauv tsheb hloov pauv lossis cov khoom muaj hnub nyoog. Tsis muaj leej twg ua qhov no manually.
Cov ntawv thov Datacenter feem ntau ua rau kev siv yooj yim dua. Kev ncav cuag luv txhais tau hais tias tsis tshua muaj kev sib cais thiab poob kev hloov pauv. Tab sis kev tiv thaiv transceiver tseem cuam tshuam txog - ntsaws siab - lub zog ib zaug - hom optic mus rau hauv ib qho multimode receiver los ntawm ib qho tsis raug yuav ua rau lub tshuab ntes tsis tsim nyog attenuation.
Kev ntsuas thiab ntsuas ntsuas faib ob txoj hauv kev. Tsis siv neeg ntsuas tshuab- cov kab ntau lawm ua tus cim transceivers, piv txwv li -xav tau programmable attenuation hla ntau txhiab lub voj voog txhua hnub. Active VOAs koom ua ke ntawm GPIB, USB, lossis ethernet. Laboratory ib puag ncig yuav siv tau; nws nyob ntawm seb ib tug neeg xav cheb attenuation programmatically los yog tsuas yog xav tau los tsoo lub zog qee zaus.
Tus nab npawb neeg tiag tiag mob siab txog
Insertion poob rau passive fixed attenuators khiav negligible tshaj qhov xav attenuation -tej zaum 0.3dB tshaj. Mechanical VOAs ntxiv me ntsis ntxiv vim lawv cov kev hloov kho. Active units sib txawv; MEMS cov qauv tsim feem ntau qhia 1-3dB qhov poob ntawm qhov tsawg kawg nkaus attenuation.
Lub hwj chim tuav txwv cov khoom siv passive ntau dua li cov khoom siv, feem ntau hais lus. Feem ntau passive attenuators qhia cov tswv yim siab tshaj plaws nyob ib ncig ntawm 300-500mW. Tshaj qhov no nrog doped - hom iav thiab thermal puas tuaj yeem ua tau. Cov ntawv thov hluav taws xob siab xav tau cov chav tshwj xeeb ntsuas rau 1W lossis dhau ntawd.
Polarization-dependent poob (PDL) plagues active technologies ntau dua passive. MEMS iav tsis yog qhov txawv ntawm lub xeev polarization, tab sis ib qho me ntsis asymmetry hauv txoj kev kho qhov muag tsim PDL. Cov khoom siv ua kua siv lead ua kua-piv polarization-raws li- yuav tsum tau ua tib zoo tsim kom txo qhov no. Cov ntawv qhia tshwj xeeb yuav pom 0.1-0.3dB PDL; Cov chav nyob hauv ntiaj teb tiag nyob rau hauv qhov kub thiab txias qee zaum dhau qhov no.
Wavelength -dependent poob (WDL) tseem ceeb rau cov ntawv thov dav dav. Ib tug passive attenuator optimized rau C-band yuav ua tau tsis zoo ntawm O-band wavelengths. Cov khoom siv nquag ntsib cov kev txwv zoo sib xws, txawm hais tias cov qauv tsim qauv tswj hwm cov lus teb ncaj nraim thoob plaws 1260-1620nm.
Nqi tiag tiag
Kuv yuav ua tsis ncaj ntawm no. Passive tsau attenuators raug nqi tseem ceeb tsis muaj dab tsi ntawm qhov ntsuas. Volume pricing poob qis dua tsib duas las ib chav tsev rau cov qauv kev teeb tsa. Txawm tias "premium" versions nrog nruj kam rau ua tsis tshua muaj tshaj tsib caug duas las.
Passive mechanical VOAs nyob hauv nruab nrab: $ 100-400 rau cov chav ua haujlwm zoo nrog qhov tsim nyog attenuation ntau thiab raug.
Active VOAs pib nyob ib ncig ntawm 300forbasicmodelsandclimbrapidly.Full-featuredunitswithethernetinterfaces,extensiveattenuationrange,lowPDL,andfastresponseeasilyreach300forba sicmodelsandclimbrapidly.Full-featuredunitswithethernetinterfaces,extensiveattenuationrange,lowPDL,andfastresponseeasilyreach1,500-2,000. Kev sib koom ua ke ntau-channel kev daws teeb meem rau ROADM daim ntawv thov-peb tab tom tham cov khoom tshwj xeeb tus nqi ntawm qhov ntawd.
Cov nqi hauv lub neej hloov qhov kev suav no me ntsis. Cov khoom siv Passive tseem ceeb yeej tsis ua rau lub cev puas tsuaj. Cov chav ua haujlwm muaj cov khoom siv hluav taws xob, cov khoom siv hluav taws xob, cov khoom siv firmware-txhua hom kev ua tsis tiav. MTBF specifications nyob ib ncig ntawm 200,000-500,000 teev suab zoo kawg nkaus kom txog rau thaum koj nco ntsoov tias kev xa tawm kaum xyoo txuas ntxiv txog 87,000 teev. Tsis yog txhua chav muaj sia nyob.
Ob peb yam tsim nyog paub
Kev tu cov fiber ntau endfaces ua ntej txhim kho ib qho attenuator tseem yog qhov tseem ceeb thiab absurdly neglected. Cov kab mob sib kis ntawm cov khoom sib txuas ntxiv ua rau qhov poob tsis tuaj yeem thiab degrades rov qab poob. Ib qho - nyem cov tshuaj ntxuav tes raug nqi tsib las rau ib qho kev tu, kwv yees li - ntawv pov hwm pheej yig.
Traceability cov ntaub ntawv tseem ceeb yog tias koj ua dab tsi tswj. Calibrated attenuators nrog NIST- daim ntawv pov thawj traceable muaj nyob rau hauv daim ntawv thov xeem; lawv raug nqi ntau dua thiab yuav tsum tau rov ua ntawv pov thawj raws sijhawm.
Hom txias qee zaus cuam tshuam nrog cov kev xav tau attenuation. Launching ib zaug - hom mus rau hauv multimode fiber ntau qee zaum siv offset patch cords los yog hom - cov kab mob txias uas ua rau cov pab pawg tshwj xeeb. Cov teeb meem sib txawv, qee zaum tsis meej pem nrog ncaj attenuation.
Kev ua lag luam txuas ntxiv mus rau kev koom ua ke. Standalone attenuators tsis ploj mus, tab sis ntau functionality consolidates rau hauv modules -VOA ua ke nrog optical keyboards, integrated rau hauv kab ntawv, embedded nyob rau hauv transceiver assemblies. Silicon photonics platforms tam sim no suav nrog ntawm -chip attenuation ntsiab rau coherent transceiver designs.
Xaiv Ntawm Lawv
Rau cov kev sib txuas zoo li qub xav tau kev txo hwj chim tas: passive attenuators, pom tseeb. Tsis muaj laj thawj rau overcomplicate qhov no.
Rau kev sim teeb tsa nrog kev rov ua dua cov txheej txheem cheb: active VOAs them rau lawv tus kheej hauv lub sij hawm txuag.
Rau cov tes hauj lwm ntau lawm uas xav tau kev hloov pauv hloov pauv: cov kev daws teeb meem nquag, nrog cov kev xaiv thev naus laus zis tshwj xeeb nyob ntawm qhov xav tau ceev thiab peev nyiaj.
Rau kev xa tawm hauv thaj chaw nyob deb nroog yam tsis muaj lub zog ntseeg tau: passive yeej los ntawm lub neej ntawd.
Txoj kev sib xyaw ua ke-passive fixed attenuators rau bulk attenuation ntxiv rau kev ua haujlwm ntawm VOA rau kev kho kom zoo- qee zaus ua rau muaj kev lag luam. Siv tus nqi pheej yig 20dB taag attenuator kom ze, cia ib qho txwv - thaj chaw nquag tswj qhov seem 0-10dB kom meej.
Dhau ntawm cov lus qhia no, cov ntsiab lus tseem ceeb. Network architecture, lub tswv yim ntawm kev ua haujlwm, kev tswj hwm uas twb muaj lawm, kev paub txog cov neeg ua haujlwm, kev sib raug zoo ntawm cov neeg muag khoom-txhua yam cuam tshuam tiag tiag - kev txiav txim siab hauv ntiaj teb. Qhov kev xaiv zoo tshaj plaws tsis yog ib txwm ua qhov zoo tshaj plaws.
