简介:本文用光荧光(PL)方法研究了磷离子注入具有两个不同发射波长的InGaAsP/InP双量子阱结构引起的混合.注入能量为120keV,剂量范围为1×1011-1×1014/cm2.注入后,在高纯氮保护下,样品在700℃进行快速热退火30秒.实验结果表明,小剂量注入(~1011/cm2)能较好地诱导近表面阱的混合,且两个阱保持了不同发射波长,说明离子注入诱导量子阱混合与注入深度有关.大剂量注入(>1012/cm2)时,发射波长为1.59μm量子阱混合的程度(蓝移值大于130nm)超过了1.52μm量子阱混合的程度,且两个阱的PL发射峰基本上合并成一个单峰.
简介:Theopticalparametersforthreesamplesofintrinsic,dopedSianddopedMg(AlxGa1-x)yIn1-yPpreparedbytheMOCVDonGaAssubstrateweremeasuredbyusingellipsometryandwerecalculatedbythetwo-layerabsorptionfilmmodel.Theresultsobtainedwerediscussed.Thegrownratesandthicknessofoxidiclayerontheintrinsic(AlxGa1-x)yIn1-yPsurfaceexposedintheatmospherewerestudied.Alineardependenceofoxidiclayerthicknessonthetimewasobtained.
简介:RamanscatteringspectroscopyisappliedtoinvestigatethephononmodesinGaxIn1-xP(x=0.52)and(AlxGa1-x)0.51In0.49P(x=0.29)alloys.Two-modebehaviorinGaxIn1-xPandthree-modebehaviorin(AlxGa1-x)0.51In0.49Pareobserved.InorderedGaxIn1-xP,weclearlydistinguishtheTO1(GaP-like)modeandthesplittingofLO1(GaP-like)andLO2(InP-like)modes,whichisbelievedtobetheresultofsuperlatticeeffectofordering,andtheLO1+LO2mode,whichisobservedforthefirsttime.Inadditiontotheb/aratio,it'sfoundthattherelativeintensityoftheFLAandtheLO1+LO2modesalsocorrespondstothedegreeoforder.TheTO1andthesplittingofLO1andLO2devotetogethertothereductionofthe'valleydepth'.In(AlxGa1-x)0.51In0.49P,thedoublingofFLAisobserved.DuetotheinfluenceofAlcomposition,theGaP-likeLOmodebecomesashoulderoftheInP-likeLOmode.TheunresolvedRamanspectraindicatetheexistenceoforderedstructurein(AlxGa1-x)0.51In0.49Palloys.
简介:Basedonthewhiteningpropertyofwavelettransformationfor1/fnoise,thispaperaddressestheproblemofdetectingdeterministicsignalsinthepresenceof1/ffractalnoise.Thetransferfunctionofwhiteningfilterisprovidedaswellastheconditionforwhitening.ThereceiverstructurebasedonKarhunen-Loeveexpansionandthedecisionrulearealsogiven.Finallyperformanceofthedetectorisanalyzed.