Hauv kev nrhiav kom muaj peev xwm ntau dua thiab ntev dua qhov kev sib kis hauv cov kab ke sib txuas lus niaj hnub no, suab nrov, ua qhov kev txwv tseem ceeb ntawm lub cev, yeej ib txwm txwv tsis pub txhim kho kev ua tau zoo.
Hauv ib qho kev coj uaEDFAerbium-doped fiber amplifier system, txhua qhov optical transmission spontaneous transmission spontaneous emission noise (ASE) tsim kwv yees li 0.1dB, uas yog rooted hauv quantum random xwm ntawm lub teeb/electron sib cuam tshuam thaum lub sijhawm amplification.
Hom suab nrov no qhia tau tias yog picosecond theem jitter hauv lub sijhawm sau. Raws li qhov kev kwv yees ntawm tus qauv jitter, nyob rau hauv qhov xwm txheej ntawm tus lej dispersion ntawm 30ps / (nm · km), tus jitter nce ntxiv los ntawm 12ps thaum xa 1000km. Hauv qhov zaus sau, nws ua rau muaj kev txo qis ntawm qhov sib piv ntawm lub teeb liab rau lub suab nrov (OSNR), ua rau muaj kev poob qis ntawm 3.2dB (@ BER = 1e-9) hauv 40Gbps NRZ system.
Qhov kev sib tw hnyav dua los ntawm kev sib txuas ntawm cov teebmeem nonlinear fiber thiab kev tawg - qhov coefficient dispersion ntawm cov fiber ib hom (G.652) hauv lub qhov rais 1550nm yog 17ps / (nm · km), ua ke nrog kev hloov pauv theem nonlinear los ntawm kev hloov kho theem tus kheej (SPM). Thaum lub zog nkag siab tshaj 6dBm, qhov cuam tshuam SPM yuav cuam tshuam qhov pulse waveform.
Hauv lub kaw lus 960Gbps PDM-16QAM uas tau qhia hauv daim duab saum toj no, qhov qhib qhov muag tom qab 200km kis tau yog 82% ntawm tus nqi pib, thiab qhov Q factor tseem nyob ntawm 14dB (sib raug rau BER ≈ 3e-5); Thaum qhov deb txuas ntxiv mus txog 400km, qhov cuam tshuam ua ke ntawm kev hloov kho theem hla (XPM) thiab plaub nthwv dej sib xyaw (FWM) ua rau qib qhib qhov muag poob qis mus rau 63%, thiab qhov yuam kev ntawm lub kaw lus tshaj qhov kev txiav txim siab nyuaj FEC qhov yuam kev kho qhov txwv ntawm 10 ^ -12.
Nws yog ib qho tsim nyog sau tseg tias qhov zaus chirp nyhuv ntawm direct modulation laser (DML) yuav zuj zus tuaj - qhov alpha parameter (linewidth enhancement factor) tus nqi ntawm ib qho DFB laser yog nyob rau hauv qhov ntau ntawm 3-6, thiab nws qhov kev hloov pauv zaus tam sim ntawd tuaj yeem ncav cuag ± 2.5GHz (sib raug rau chirp parameter C = 2.5GHz / mA) ntawm qhov tam sim no modulation ntawm 1mA, ua rau muaj tus nqi pulse broadening ntawm 38% (cumulative dispersion D · L = 1360ps / nm) tom qab kis tau los ntawm 80km G.652 fiber.
Kev sib txuas ntawm cov channel hauv wavelength division multiplexing (WDM) systems ua rau muaj kev cuam tshuam tob dua. Piv txwv li, qhov sib nrug ntawm 50GHz channel, lub zog cuam tshuam los ntawm plaub lub nthwv dej sib xyaw (FWM) muaj qhov ntev Leff zoo li 22km hauv cov fibers optical ib txwm muaj.
Kev sib txuas ntawm cov channel hauv wavelength division multiplexing (WDM) systems ua rau muaj kev cuam tshuam tob dua. Piv txwv li, siv qhov sib nrug ntawm 50GHz channel, qhov ntev ntawm lub zog cuam tshuam uas tsim los ntawm plaub nthwv dej sib xyaw (FWM) yog Leff = 22km (sib raug rau fiber attenuation coefficient α = 0.22 dB / km).
Thaum lub zog nkag mus rau + 15dBm, qib crosstalk ntawm cov channel sib ze nce ntxiv 7dB (piv rau -30dB baseline), yuam kom lub kaw lus nce qhov kev kho qhov yuam kev pem hauv ntej (FEC) redundancy ntawm 7% mus rau 20%. Cov nyhuv hloov pauv fais fab los ntawm kev txhawb nqa Raman scattering (SRS) ua rau poob kwv yees li 0.02dB ib mais hauv cov channel wavelength ntev, ua rau lub zog poob txog li 3.5dB hauv C + L band (1530-1625nm) system. Kev them nyiaj rau lub sijhawm tiag tiag yog qhov yuav tsum tau ua los ntawm dynamic gain equalizer (DGE).
Qhov kev txwv ntawm kev ua haujlwm ntawm lub cev ntawm cov teebmeem no ua ke tuaj yeem ntsuas los ntawm cov khoom siv bandwidth nrug (B · L): B · L ntawm lub kaw lus NRZ modulation ib txwm muaj hauv G.655 fiber (dispersion compensated fiber) yog kwv yees li 18000 (Gb / s) · km, thaum nrog PDM-QPSK modulation thiab coherent detection technology, qhov ntsuas no tuaj yeem txhim kho mus rau 280000 (Gb / s) · km (@ SD-FEC nce 9.5dB).
Lub fiber ntau 7-core x 3-mode space division multiplexing fiber (SDM) uas siv tau ntev heev tau ua tiav qhov muaj peev xwm xa tau 15.6Pb/s km (qhov muaj peev xwm xa tau ib lub fiber ntau 1.53Pb/sx ntawm 10.2km) hauv chaw kuaj mob los ntawm kev tswj tsis muaj zog ntawm kev sib txuas ntawm cov tub ntxhais sib txuas (<-40dB/km).
Yuav kom mus txog qhov txwv Shannon, cov txheej txheem niaj hnub no yuav tsum tau ua ke txais yuav qhov probability shaping (PS-256QAM, ua tiav 0.8dB shaping gain), neural network equalization (NL compensation efficiency zoo dua 37%), thiab distributed Raman amplification (DRA, gain slope accuracy ± 0.5dB) technologies los nce Q factor ntawm ib tus neeg nqa khoom 400G PDM-64QAM kis los ntawm 2dB (los ntawm 12dB txog 14dB), thiab so qhov OSNR kam rau siab rau 17.5dB/0.1nm (@ BER=2e-2).
Lub sijhawm tshaj tawm: Lub Rau Hli-12-2025