简介:AninitialstructuredesignofMMI1×8opticalpowersplittersisreported.ThewaveguidematerialisSi-basedSiO2Ge-dopedanddepositedbyPECVDmethod.Embeddedstripstructureisimpliedinthesectiondesign.ByusingBPM-CAD,afavorableresultisobtainedthatthisdevicehasasounduniformityandfairlylowloss.Meanwhile,simulationsofdesignswithcertainchangedparametersisalsoimplementedforabetterdesignconfiguration.
简介:Thesilicon-on-insulator(SOI)1×2Y-junctionopticalwaveguideswitchhasbeenproposedandfabricated,whichisbasedonthelargecross-sectionsingle-moderibwaveguidecondition,thewaveguide-vanishingeffectandthefree-carrierplasmadispersioneffect.Intheswitch,theSOItechniqueutilizersiliconandsilicondioxidethermalbondingandback-polishing.Theinsertionlossandextinctionratioofthedevicearemeasuredtobelessthan4.78dBand20.8dBrespectivelyatawavelengthof1.3μmandaninjectioncurrentof45mA.Responsetimeisabout160ns.
简介:Themixedl1/H2optimizationproblemforMIMO(multipleinput-multipleoutput)discrete-timesystemsisconsidered.Thisproblemisformulatedasminimizingthel1-normofaclosed-looptransfermatrixwhilemaintainingtheH2-normofanotherclosed-looptransfermatrixatprescribedlevel.ThecontinuitypropertyoftheoptimalvalueinrespecttochangesintheH2-normconstraintisstudied.Theexistenceoftheoptimalsolutionsofmixedll/H2problemisproved.Becausethesolutionofthemixedl1/H2problemisbasedonthescaled-Qmethod,itavoidsthezerointerpolationdifficulties.Theconvergentupperandlowerboundscanbeobtainedbysolvingasequenceoffinitedimensionalnonlinearprogrammingforwhichmanyefficientnumericaloptimizationalgorithmsexist.