简介：Weinvestigatedtheeffectofphotodynamictherapy(PDT)withhematoporphyrinmonomethylether(HMME)ontheviabilityofStreptococcusmutans(S.mutans)cellsonbiofilmsinvitro.Streptococcusmutansistheprimaryetiologicalagentofhumandentalcaries.Sincedentalcariesarelocalizedinfections,suchplaque-relateddiseaseswouldbewellsuitedtoPDT.Thediodelaserusedinthisstudyhadthewavelengthof635nm,whoseoutputpowerwas10mWandtheenergydensitywas12.74J/cm~2.HMMEwasusedasphotosensitizer.Sampleswerepreparedanddividedintofivegroups:(1)HMME;(2)Laser;(3)HMME+Laser;(4)Controlgroup(+)withchlorhexidine;and(5)Controlgroup(-)withsterilephysiologicalsaline.InoculumofS.mutansincubatedwithHMMEalsoexaminedwithfluorescencemicroscopy.PDTexhibitedasignificantly(P<0.05)increasedantimicrobialpotentialcomparedwith20μm/mLHMMEonly,laseronly,0.05%chlorhexidine,and0.9%sterilephysiologicalsaline,whichreducedtheS.mutansofthebiofilmmosteffectively.Laserand0.05%chlorhexidinewerecausedreductionintheviablecountsofS.mutanssignificantlydifferent(P<0.05)also,butthesetwotesttreatmentsdidnotstatisticallydifferfromeachother.HMMEgroupdidnotstatisticallydifferwithnegativecontrolgroup.FluorescencemicroscopyindicatedthatHMMElocalizedprimarilyintheS.mutansofthebiofilm.ItwasdemonstratedthatHMME-mediatedPDTwasefficientatkillingS.mutansofbiofilmsandausefulapproachinthetreatmentofdentalplaque-relateddiseases.

简介：Whenasilicaopticalfiberisusedfortransmittingultraviolet(UV)light,theproblemsassociatedwiththedamageandtransmissiondeteriorationofsilicafiberintheUVregionneedtobesolvedinthefabricationprocess.Inthispaper,animprovedsilicafiberfabricationprocesswaspresentedtoenhanceUVtransmission,whichcombinedtheUVpre-irradiationonhigh-OHconcentrationpreformwithheattreatmentwhiledrawingfiber.Theimpactofthestructuraldefectsandcolorcenterswasdiminishedgreatlybythenewmethodoffabrication.Theexperimentalresultsaccordedwiththetheoreticalanalysis,andtransmissionwasimprovedabout0.4-0.7dB/mforwavelengthfrom350to400nm.

简介：Atheoreticalmodelofanonlinearhyperbolicmetamaterialispresentedintheformofastackofsubwavelengthlayersoflinearplasmonicandnonlineardielectricmaterials.Abroadpictureofthepropertiesofevanescentwaves(high-kmodes)inthisstackisinvestigatedbyplottingglobaltransmissiondiagrams.Thepresenceofnonlinearitystronglymodifiesthesediagrams.Theemergenceandmodificationofnonlinearevanescentwavesisobserved.Somesignaturesofnonlinearphenomenonsuchasformationoforbitsandtrajectoriesaroundfixedpointsarealsoseeninourwork.

简介：Anovelbroadbandtransmissionmethodtodeterminepolymerfilmthicknessduringmanufacturingisproposed,andameasurementsystemisdevelopedbasedonthismethod.TherelationshipbetweenbroadbandopticalpowerandfilmthicknessisdeducedaccordingtotheLambert-Beerlaw.Thesystemiscomposedofahalogenlightandanopticalpowermeter.Resultsshowthatthemeasurementerrorofthismethodisapproximately1μm,andtheresolutionofthesystemisbelow0.4μmforpolymerfilmswithlessthan100-μmthickness.

简介：WeanalyzetherandomdisturbanceinthetransmissionoflightthroughaspinningGlan-Thompsontypeprismpolarizer.ThedisturbancemakesthedependenceofthetransmissionontherotationanglesignificantlydeviatesfromtheMaluscosine-squaredlawandseverelyspoilstheoutputlightquality.Slightvibrationofthepolarizerasitrotatescombingthemulti-beam-interferenceeffectraisesthedisturbance.Furtheranalysisrevealsthesensitivedependenceofthedisturbanceonthecomposingmaterialoftheprismgap,andtheappropriateselectionofsuchmaterialcanmakethedisturbanceminimizetoverydesirablelevels.Themodelresultsshowquitegoodagreementwithexperiments.

简介：Theeffectofannealingconditiononsputteredindiumtinoxide(ITO)filmsonquartzwiththethicknessof200nmischaracterizedtoshowenhancedopticaltransparencyandoptimizedelectricalcontactresistivity.Theas-depositedgrownITOfilmexhibitsonly65%and80%transmittanceat532and632.8nm,respectively.Afterannealingat475°Cfor15min,theITOfilmisrefinedtoshowimprovedtransmittanceatshorterwavelengthregion.Thetransmittancesof88.1%at532nmand90.4%at632.8nmcanbeobtained.The325-nmtransmittanceofthepost-annealedITOfilmisgreatlyincreasedfrom12.7%to41.9%.Optimizedelectricalpropertycanbeobtainedwhenannealingbelow450°C,leadingtoaminimumsheetresistanceof26Ω/square.SuchanITOfilmwithenhancedultraviolet(UV)transmittancehasbecomeanalternativecandidateforapplicationsincurrentUVphotonicdevices.Themorphologyandconductanceoftheas-depositedandannealedITOfilmsaredeterminedbyusinganatomicforcemicroscopy(AFM),showingagreatchangeontheuniformitydistributionwithfiniteimprovementonthesurfaceconductanceoftheITOfilmafterannealing.

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简介：WecreateaGaNphotocathodebasedongradedAlxGa1-xNbufferlayerstoovercometheinfluenceofbuffer-emissionlayerinterfaceonthephotoemissionoftransmission-modeGaNphotocathodes.Agateshapedspectralresponsewitha260-nmstartingwavelengthanda375-nmcut-offwavelengthisobtained.Averagequantumefficiencyis15%andshortwavelengthresponsesarealmostequivalenttolongwavelengthones.Thefittedinterfacerecombinationvelocityis5×104cm/s,withnegligiblemagnitude,provingthatthedesignofthegradedbufferlayersisefficientinobtaininggoodinterfacequalitybetweenthebufferandtheemissionlayer.

简介：Aquasi-cycliclow-densityparitycheck(QC-LDPC)codeisconstructedbyanimp

简介：Thetransmissionpropertiesofone-dimensionalphotoniccrystalscontainingdouble-negativeandsingle-negativematerialsarestudiedtheoretically.Aspecialkindofphotonicbandgapisfoundinthisstructure.Thisgapisinvariantwithscalingandinsensitivetothicknessfluctuation.Butwhenchangingtheratioofthethicknessoftwomedia,thewidthofthegapcouldbeenlarged.Thedefectmodesareanalyzedbyinducingalineardefectlayerinthestructure.Itisfoundthatthenumberofdefectmodeswillincreasewhenthethicknessofthedefectlayerbecomeslarger.更多还原

简介：Wedemonstrateadigitalopticalcommunicationsystembasedonminimumshiftkeying(MSK)signaltransmissionwithcoherentdetection.5-Gb/sMSKsignalcantransmitovera160-kmstandardsinglemodefiber(SSMF)withoutphasecompensation.Atthereceiver,weusedata-aidedchannelestimationandfrequencydomainequalization(FDE)techniquesinthedigitalsignalprocessing(DSP)algorithm,thenanalyzeitsperformancecharacteristicscomparedwithquadraturephaseshiftkeying(QPSK)format.ThesimulationresultsshowthattheMSKformatwillbeapotentialcandidatefornext-generationaccessnetwork.

简介：Thisletterpresentsalowcostsolutionforwavelengthdivisionmultiplexedorthogonalfrequencydivisionmultiplexedpassiveopticalnetwork(WDM-OFDM-PON)withwidelytunableopticalfilterandlinearsmallform-factorpluggable(SFP)module.With9-nmtunablerangefrom1551to1560nm,thetunablefiltercansupportupto10-channel100-GHzspacingWDMPONsystem.Alinearavalanchephotodiode(APD)basedSFP+moduleisdesignedforopticalOFDMsignaldemodulation,whichcanprovidebetterreceiverperformancecomparedwithlimitingAPDmodule.Experimentalresultsshowthat～34dBpowerbudgetcanbeachievedin4×5-GbpsWDM-OFDM-PONsystem,whichcansatisfythetransmissionrequirementsofnextgenerationPONsystem.

简介：Anovelmethodfordistortion-freeopticalpulsetransmissionistheoreticallyproposedandsimulated,inwhichtwotimelensesformedbydispersionfibersandquadraticphasemodulationsareutilized.OneisusedasanopticalinverseFouriertransformation(OIFT)devicetotransformtheinitialtime-domaindatatofrequency-domainoneatthetransmitterandtheotherasanopticalFouriertransformation(OFT)devicetorecoverthedataatthereceiver.Byusingtheunchangedspectralenvelopeinlinearopticalfibercommunication,theinitialdatacanberecovered.Throughsimulations,a10×100Gb/sintensitymodulateddirect-detection(IM-DD)densewavelengthdivisionmultiplexing(DWDM)systemover2000kmtransmissionwithoutthecompensationforpolarizationmodedispersion(PMD)anddispersionslopeisachieved,whichcanbeusedtoupgradethecurrent10-Gb/sIM-DDsystemtoa100-Gb/sonedirectly.

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简介：Alowcost8×10-Gb/stransmissionsystemover1500kmonconventionalfiberusingchirpedfiberBragggrating(CFBG)asdispersioncompensatorisdemonstrated.Thebiterrorrate(BER)below10-10at1500kmisobtained.Thechannelspacingis0.8nmandtheopticalamplifierspacingis100km.Only16erbium-dopedfiberamplifiers(EDFAs)areused.

简介：Non-uniformstep-sizedistributionisimplementedforsplit-stepbasednonlinearcompensationinsingle-channel112-Gb/s16quadratureamplitudemodulation(QAM)transmission.Numericalsimulationsofthesystemincludinga20×80kmuncompensatedlinkareperformedusinglogarithmicstepsizedistributiontocompensatesignaldistortions.50%ofreductioninnumberofstepswithrespecttousingconstantstepsizesisobserved.Theperformanceisfurtherimprovedbyoptimizingnonlinearcalculatingposition(NLCP)incaseofusingconstantstepsizeswhileNLCPoptimizationbecomesunnecessarywhenusinglogarithmicstepsizes,whichreducesthecomputationaleffortduetouniformlydistributednonlinearphaseforallsuccessivesteps.

简介：Weexperimentallydemonstratea4-Gb/sradio-over-fiber(RoF)systemwith40-kmfiberand2-mwirelessdistancedownstreamat100-GHzcarrier.Tothebestofourknowledge,thisisforthefirsttimeinChinatorealizeopticalwirelesslinkat100GHz.Inthisletter,simpleintensitymodulatorwithdirectdetector(IM-DD)modulationisemployedandopticalpowerpenaltyafter40-kmsinglemodefiber(SMF)-28and2-mairlinkis3.2dBwithbit-error-rate(BER)at1×109.

简介：ByusingPDM-OFDM-16QAMmodulation,all-Ramanamplification,coherentdetection,and7%forwarderrorcorrection(FEC)threshold,wesuccessfullydemonstrate63-Tb/s(368×183.3-Gb/s)signalover160-kmstandardsinglemodefiber(SSMF)transmissionintheC-andL-bandswith25-GHzchannelspacing.368opticalchannelswithbandwidthspacingof25GHzaregeneratedfrom16externalcavitylasersources.After160-kmSSMFtransmission,alltestedbiterrorrate(BER)areunder3.8×10-3,whichcanberecoveredby7%FECthreshold.Withineachchannel,weachievethespectralefficiencyof6.85bit/s/HzinC/Lband.