简介：Inrecentyears,agreatdealofefforthasbeenmadetoacreateterahertz(THz)waveabsorberbasedonmetamaterials(MM).Metamaterialsabsorbershaveavarietyofpotentialapplicationsincludingthermalemitters,detector,stealthtechnology,phaseimaging,etc.Inthispaper,wefirstlyintroducethebasicstructureandworkprincipleoftheTHzMMabsorbers,andatransmissionlinemodelisdevelopedfordevicesanalysis.ToexpandtheapplicationofTHzabsorbers,dual-bandandbroadbandTHzMMabsorbersaredesigned,fabricated,andmeasured.Attheendofthisarticle,thefuturedevelopmenttrendsofMMabsorbersarediscussed.

简介：我们调查metamaterial系统的动态特征，例如在散cloaking系统，并且延长cloaking系统的工作频率范围的superlens，理想的cloaking系统上的诱发性限制，松驰进程和必要元素的时间的连贯获得。我们的学习的关键点是metamaterials的物理散性质，它内在地是著名的是强烈散。与物理分散，新物理图画能为在metamaterial内宣传的波浪被获得，例如这个组在superlens和外套，真实metamaterial系统上的诱发性限制，和为设计优化的必要元素内的波浪的延迟的时间。因此，我们相信metamaterials的动态学习将是为进一步的研究的一个重要方向。所有理论推导和结论被强大的有限差别的时间域模拟表明。

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简介：Weinvestigatethenonlinearresponseofterahertz(THz)metamaterialperfectabsorbersconsistingofelectricsplitringresonatorsonGaAsintegratedwithapolyimidespacerandgoldgroundplane.Theseperfectabsorbersonbulksemi-insulatingGaAsarecharacterizedusinghigh-fieldTHztime-domainspectroscopy.Theresonancefrequencyredshifts20GHzandtheabsorbanceisreducedby30%astheincidentpeakfieldisincreasedfrom30to300kV/cm.ThenonlinearresponsearisesfromTHzfielddriveninterbandtransitionsandintervalleyscatteringintheGaAs.ToeliminatetheFresnellossesfromtheGaAssubstrate,wedesignandfabricateaflexiblemetamaterialsaturableperfectabsorber.Theabilitytocreatenonlinearabsorbersenablesappealingapplicationssuchasopticallimitingandself-focusing.

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

简介：Aterahertzmetamaterialsensoradoptingthemetamaterial-basedelectromagneticallyinducedtransparency(EIT)effectispresentedfordeterminingthe1,4-dioxaneconcentrationinitsaqueoussolution.Themetamaterialsensor,whichconsistsofanEITelementunitwithacut-wiremetallicresonatorandtwosplit-ringmetallicresonatorsfabricatedona490-μmthicksiliconsubstrate,operatesinatransmissiongeometry.TheEITpeakwasred-shiftedanddecreasedwiththeincreaseofthewatervolume.Amaximumredshiftabout54GHzoftheEITpeakwasdetectedbetweenthe1,4-dioxaneandwater.ThepresentedlinearbehaviorandhighsensitivityoftheEITpeakdependingonthewaterconcentrationpaveanovelavenueforsensorapplications.

简介：Wepresentatheoreticalstudyofthepropagationpropertiesofpolarizedphotonspassingthroughthecavitywithananisotropicmetamaterial.Wefindthattheresonantpeaksoftransmissionappearforphotonspolarizedinacertaindirectioncorrespondingtoanegativeelementofthepermittivitytensor.Thisindicatesthepotentialforapplyingsuchcavitystructuresasfiltersforphotonswithcertainpolarizations.Theresonantpeakoftransmissionforphotonshavingagivenfrequencycanbeachievedbyadjustingthethicknessesoftheairandmetamaterial.Ifthefrequencyoftheincidentphotonsandthethicknessofthemetamaterialarefixed,thecavitystructurecanbeusedasaphotonswitchcontrolledbythethicknessoftheair.Theeffectoftheabsorptionisconsidered,andtheresultshowsthatthetransmissionpeakalwaysappears,evenformetamaterialswithlargeabsorption.Finally,thepolarizationmanipulationofsuchstructuresisexplored.

简介：Anultrasensitivemetamaterialsensorbasedondouble-slotverticalsplitringresonators(DVSRRs)isdesignedandnumericallycalculatedintheterahertzfrequency.ThisDVSRRdesignproducesafundamentLCresonancewithaqualityfactorofabout20whentheincidencemagneticfieldcomponentnormaltotheDVSRRarray.TheresonantcharacteristicsandsensingperformanceoftheDVSRRarraydesignaresystematicallyanalyzedemployingacontrastmethodamongthreesimilarverticalsplitringresonator(SRRs)structures.Theresearchresultsshowthattheeliminationofbianisotropy,inducedbythestructuralsymmetryoftheDVSRRdesign,helpstoachieveLCresonanceofahighqualityfactor.LiftingtheSRRsupfromthesubstratesharplyreducesthedielectriclossintroducedbythesubstrate.AllthesefactorsjointlyresultinsuperiorsensitivityoftheDVSRRtotheattributesofanalytes.Themaximumrefractiveindexsensitivityis788GHz/RIUor1.04×10~5nm∕RIU.Also,theDVSRRsensormaintainsitssuperiorsensingperformanceforfabricationtolerancerangingfrom-4%to4%andwiderangeincidenceanglesupto50°underbothTEandTMilluminations.

简介：Analysisofthescatteringparameters(S-parameters)ofplanarN-waymetamaterialpowerdividers/combinersmostlyusescommercialmicrowavecircuitsimulatorsduetothelargecircuitsizeinvolved.Thispaperpresentsanefficientcircuitmodelingapproach,whichisbasedonthemulti-inputandmulti-outputtransmissionmatrix(T-matrix)method,toanalyzetheS-parameterofaplanarnine-waymetamaterialpower-divider/combinerstructure.S-parametercomputationresultsareshowningoodagreementwiththesimulationresultsbyusingtheAgilentadvanceddesignsystem(ADS)andmeasurementresults.ThecomputationtimeofanN-waymetamaterialpowerdivider/combinerwithN=5,9,13,and17usingT-matrixmethodisalsocomparedwiththoseofADSandAWRMicrowaveOffice(MWO)todemonstrateitscomputationalefficiency.

简介：Forapreviouslysimulatedeight-broadbandnegative-refraction-indexchiralmetamaterial,weuseS-parameterretrievalmethodstodeterminethecomplexeffectivepermittivity,permeability,andtheimpedance.Wealsocalculatethefigureofmerit,whichisdefinedastheratiooftherealandtheimaginaryrefractioncomponents,andcompareitwiththoseoffishnetmetamaterials.Thesimulationresultsshowthatourchiralmetamaterialexhibitshightransmissionandimpedancematchingtoavacuum.Also,wedeterminethattheelectricandmagneticdipolesofthesurfaceplasmonsplayanimportantroleindeterminingthenineresonancefrequencies.Therefore,thisinvestigationprovidesanexperimentalbasisfordevelopingmetamaterialdeviceswithmultipleandbroadresonancefrequencybands.

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简介：Wedemonstrateaphotonicbandgap(PBG)fromone-dimensional(1D)periodicstructurescreatedbyadouble-layerunitcellwithanairlayerandananisotropicnonmagneticleft-handedmetamaterial(LHM)layerwhosepermittivityelementsarepartiallynegative.TherequirementsimposedonthematerialsandstructurestorealizeaPBGarederivedwhenthefrequencyisaboveorbelowthecutofffrequency,andthetransmissionpropertiesofthePBGarediscussedbyutilizing4×4transfer-matrixmethodwithdispersivesemiconductormetamaterial.

简介：Wenumericallydemonstrateanovelultra-broadbandpolarization-independentmetamaterialperfectabsorberinthevisibleandnear-infraredregioninvolvingthephase-changematerialGe2Sb2Te5（GST）.Thenovelperfectabsorberschemeconsistsofanarrayofhigh-indexstrong-absorbanceGSTsquareresonatorsseparatedfromacontinuousAusubstratebyalow-indexlosslessdielectriclayer（silica）andahigh-indexGSTplanarcavity.Threeabsorptionpeakswiththemaximalabsorbanceupto99.94%areachieved,owingtotheexcitationofplasmon-likedipolarorquadrupoleresonancesfromthehigh-indexGSTresonatorsandcavityresonancesgeneratedbytheGSTplanarcavity.Theintensitiesandpositionsoftheabsorptionpeaksshowstrongdependenceonstructuralparameters.AheattransfermodelisusedtoinvestigatethetemporalvariationoftemperaturewithintheGSTregion.TheresultsshowthatthetemperatureofamorphousGSTcanreachupto433Kofthephasetransitiontemperaturefromroomtemperatureinjust0.37nswitharelativelylowincidentlightintensityof1.11×108W∕m2,duetotheenhancedultra-broadbandlightabsorbancethroughstrongplasmonresonancesandcavityresonanceintheabsorber.Thestudysuggestsafeasiblemeanstolowerthepowerrequirementsforphotonicdevicesbasedonathermalphasechangeviaengineeringultra-broadbandlightabsorbers.