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

简介：利用4.5MeV的氪离子（Kr^17＋）辐照（100）晶向本征未掺杂和高掺锌（P型）、（100）和（110）混合晶向的高掺硅（N型）砷化镓（GaAs）半导体材料,辐照注量为1×10^12～3×10^14cm^-2,测试辐照后材料的拉曼光谱。随着辐照注量增大,材料的纵向光学（longitudinaloptical,LO）声子峰向低频方向移动,出现了明显的非对称展宽,并且N型样品辐照后,晶体结构损伤要大于P型与本征未掺杂样品。3种类型样品的LO峰频移随辐照损伤的变化趋势一致,研究表明,掺杂元素不影响材料本身的晶体结构,可能是因为混合晶向的生长方式导致辐照后N型GaAs结构稳定性变差。

简介：TheeffectsofgrowthtimeonthestructureandmorphologyofcubicGaNnucleationlayersonGaAs(001)substratesbymetalorganicchemicalvapordeposition(MOCVD)havebeeninvestigatedusingasynchrotronX-raydiffraction(XRD).TheXRDresultsshowthattheGaN111reflectionsat54.75°inχareameasurablecomponent,howeverthe002reflectionsparalleltoGaAs(001)surfacearenotdetected.TheXRDΦscansandpolefiguresgiveaconvincingproofthattheGaNnucleationlatyersshowexactlythecubicsymmetricalstructure.Thecoherencelengthsalongtheclose-packed<111>directionestuimatedfromthe111peakarenanometerorderofmagnitude,Theoptimalphotoluminescence(PL)spectrumwasobtainedfromthecubicGaNepilayerdepositedonthenucleationlayerfor60sec.

简介：AseriesofGaAs/AlAsmultiple-quantumwellsdopedwithBeisgrownbymolecularbeamepitaxy.Thephotoluminescencespectraaremeasuredat4,20,40,80,120,and200K,respectively.Therecombinationtransitionemissionofheavy-holeandlight-holefreeexcitonsisclearlyobservedandthetransitionenergiesaremeasuredwithdifferentquantumwellwidths.Inaddition,atheoreticalmodelofexcitonicstatesinthequantumwellsisused,inwhichthesymmetryofthecomponentoftheexcitonwavefunctionrepresentingtherelativemotionisallowedtovarybetweenthetwo-andthreedimensionallimits.Then,withintheeffectivemassandenvelopefunctionapproximation,therecombinationtransitionenergiesoftheheavy-andlight-holeexcitonsinGaAs/AlAsmultiple-quantumwellsarecalculatedeachasafunctionofquantumwellwidthbytheshootingmethodandvariationalprinciplewithtwovariationalparameters.Theresultsshowthattheexcitonsareneither2Dnor3Dlike,butareinbetweenincharacterandthatthetheoreticalcalculationisingoodagreementwiththeexperimentalresults.

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简介：Thispaperpresentsafiniteelementcalculationfortheelectronicstructureandstraindistributionofself-organizedInAs/GaAsquantumrings.Thestraindistributioncalculationsarebasedonthecontinuumelastictheory.Anidealthree-dimensionalcircularquantumringmodelisadoptedinthiswork.Theelectronandheavy-holeenergylevelsoftheInAs/GaAsquantumringsarecalculatedbysolvingthethree-dimensionaleffectivemassSchro¨dingerequationincludingthedeformationpotentialandpiezoelectricpotentialuptothesecondorderinducedbythestrain.Thecalculatedresultsshowtheimportanceofstrainandpiezoelectriceffects,andtheseeffectsshouldbetakenintoconsiderationinanalysisoftheoptoelectroniccharacteristicsofstrainquantumrings.

简介：为做调整的GaAs/Al0.3量井用解决时间的magneto-Kerr旋转大小被学习的Ga0.7。电子旋转松驰时间和它的在里面飞机anisotropy作为光学地注射的电子密度的功能被学习。而且，Rashba的相对力量和联合的Dresselhausspinorbit回答，并且这样观察旋转松驰时间anisotropy，被532nm的另外的刺激进一步调节连续波浪激光，经由一个光gating方法表明有效旋转松驰操作。

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简介：Weproposedynamicterahertz(THz)emissionmicroscopy(DTEM)tovisualizetemporal–spatialdynamicsofphotoexcitedcarriersinelectronicmaterials.DTEMutilizesTHzpulsesemittedfromasamplebyprobepulsesirradiatedafterpumppulseirradiationtoperformtime-resolvedtwo-dimensionalmappingoftheTHzpulseemission,reflectingvariouscarrierdynamics.Usingthismicroscopy,weinvestigatedcarrierdynamicsinthegapregionoflow-temperature-grownGaAsandsemi-insulatingGaAsphotoconductiveswitchesoftheidentical-dipoletype.TheobservedDTEMimagesarewellexplainedbythechangeintheelectricpotentialdistributionbetweentheelectrodescausedbythescreeningeffectofthephotoexcitedelectron-holepairs.

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简介：OpticalsimulationsofGaAs/AlGaAsthin-filmwaveguideswereperformedforinvestigatingthedependenceofthemodalbehavioronwaveguidegeometryandtheresultinganalyticalsensitivity.Simulationswereperformedfortwodistinctmid-infraredwavelengths,therebydemonstratingthenecessityofindividuallydesignedwaveguidestructuresforeachspectralregimeofinterest.Hence,themodalbehavior,sensitivity,andintensityoftheevanescentfieldwereinvestigatedviamodelingstudiesat1600and1000cm-1,therebyconfirmingtheutilityofsuchsimulationsfordesigningmid-infraredsensorsbasedonthin-filmwaveguidetechnology.

简介：Usingasimpletwo-parameterwavefunction,wecalculatevariationallythebindingenergyofpositivelyandnegativelychargedexcitonsinGaAs/AlxGa1-xAsquantumwellsforwellwidthsfrom10to300A.Weconsidertheeffectofeffectivemass,dielectricconstantmismatchinthetwomaterials,andthewholecorrelationamongtheparticles.Theresultsarediscussedandcomparedindetailwithpreviousexperimentalandtheoreticalresults,whichshowfairagreementwiththem.

简介：Wereportlow-noise,high-performancesingletransversemode1.3μmInAs/GaAsquantumdotlasersmonolithicallygrownonsilicon(Si)usingmolecularbeamepitaxy.Thefabricatednarrow-ridge-waveguideFabry–Perot(FP)lasershaveachievedaroom-temperaturecontinuous-wave(CW)thresholdcurrentof12.5mAandhighCWtemperaturetoleranceupto90°C.Anultra-lowrelativeintensitynoiseoflessthan-150dB∕Hzismeasuredinthe4–16GHzrange.Usingthislow-noiseSi-basedlaser,wethendemonstrate25.6Gb/sdatatransmissionover13.5kmSMF-28.Theselow-costFPlaserdevicesarepromisingcandidatestoprovidecost-effectivesolutionsforuseinuncooledSiphotonicstransmittersininter/hyperdatacentersandmetropolitandatalinks.

简介：模式获得光谱被Fourier系列扩大方法forInAs/GaAs量点(QD)测量有在不同注射水流的QD的七栈的激光。有特殊山峰的Gainspectra在大约1210nmand1300nm的短、长的波长被观察。为有1060亩m的洞长度的QD激光，长波长的山峰获得首先慢慢地增加或甚至快速作为短波长度增加的山峰获得与注射水流减少，并且当注射水流进一步增加，最后在接近浸透的价值前快速增加。

简介：反响的刺激被用来在量井产生相片激动的搬运人由有或没有一个pn连接比较在量井之间的光致发光结果观察搬运人交通的过程。它在实验直接被观察大多数在有一个pn连接的量井的相片激动的搬运人逃离量井和形式光电流而非放松到量井的扎根的状态。多重量井的相片吸收系数被一个pn连接也提高。结果为使用低维的结构的太阳能电池和光电探测器铺平一条新奇道路。

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简介：文章采用日本产的ＣＮ１５１１８及扫描型双晶形貌测角仪直接拍摄了ＭＢＥ生长的Ｇａｌ－ｘＡＬｘＡｓ／ＧａＡｓ外延层和衬底层的形貌像，观察到面层中存在失配位错，单方向位错线晶面取向差等缺陷。并比较了生长温度对外延层质量的影响。

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