models.rf.photonic crystal英文文献资料

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1、SolvedwithCOMSOLMultiphysics4.3aPhotonicCrystalPhotoniccrystaldevicesareperiodicstructuresofalternatinglayersofmaterialswithdifferentrefractiveindices.Waveguidesthatareconfinedinsideofaphotoniccrystalcanhaveverysharplow-lossbends,whichmayenableanincreaseinintegrationdensityofseveralor

2、dersofmagnitude.IntroductionThismodeldescribesthewavepropagationinaphotoniccrystalthatconsistsofGaAspillarsplacedequidistantfromeachother.Thedistancebetweenthepillarspreventslightofcertainwavelengthstopropagateintothecrystalstructure.Dependingonthedistancebetweenthepillars,waveswithin

3、aspecificfrequencyrangearereflectedinsteadofpropagatingthroughthecrystal.Thisfrequencyrangeiscalledthephotonicbandgap(Ref.1).ByremovingsomeoftheGaAspillarsinthecrystalstructureyoucancreateaguideforthefrequencieswithinthebandgap.Lightcanthenpropagatealongtheoutlinedguidegeometry.Outgoi

4、ngwavePillar(GaAs)IncomingwaveAir©2012COMSOL1

5、PHOTONICCRYSTALSolvedwithCOMSOLMultiphysics4.3aModelDefinitionThegeometryisasquareofairwithanarrayofcircularpillarsofGaAsasdescribedabove.Somepillarsareremovedtomakeawaveguidewitha90°bend.TheobjectiveofthemodelistostudyTEwavespropagatingth

6、roughthecrystal.Tomodelthese,useascalarequationforthetransverseelectricfieldcomponentEz,22–∇∇⋅E–nkE=0z0zwherenistherefractiveindexandk0isthefree-spacewavenumber.Becausetherearenophysicalboundaries,youcanusethescatteringboundaryconditionatallboundaries.SettheamplitudeEzto1ontheboundary

7、oftheincomingwave.ResultsandDiscussionFigure1containsaplotofthezcomponentoftheelectricfield.Itclearlyshowsthepropagationofthewavethroughtheguide.Figure1:Thezcomponentoftheelectricfieldshowinghowthewavepropagatesalongthepathdefinedbythepillars.2

8、PHOTONICCRYSTAL©2012COMSOLSolvedwithCOMS

9、OLMultiphysics4.3aIftheangularfrequencyoftheincomingwaveislessthanthecutofffrequencyofthewaveguide,thewavedoesnotpropagatethroughtheoutlinedguidegeometry.InFigure2thewavelengthhasbeenincreasedbyafactorof1.2.Figure2:Alongerwavelengthwillnotpropagatethroughtheguide.Thispictureshowstheno

10、rmoft