简介：TheCa_2SiO_4:Dy~(3+)phosphorwassynthesizedbythehightemperaturesolid-statereactionmethodinair.TheemissionspectrumofCa_2SiO_4:Dy~(3+)phosphorshowsseveralbandsat486,575,and665nmunderthe365-nmexcitation.TheeffectsofLi~+,Na~+,andK~+ontheemissionspectrumofCa_2SiO_4:Dy~(3+)phosphorwerestudied,TheresultsshowthattheemissionspectrumintensityisgreatlyinfluencedbyLi~+,Na~+,andK~+.Thechargecompensationconcentrationcorrespondingtothemaximumemissionintensityisdifferentwithdifferentchargecompensations.

简介：Weexperimentallydemonstratea4-Gb/sradio-over-fiber(RoF)systemwith40-kmfiberand2-mwirelessdistancedownstreamat100-GHzcarrier.Tothebestofourknowledge,thisisforthefirsttimeinChinatorealizeopticalwirelesslinkat100GHz.Inthisletter,simpleintensitymodulatorwithdirectdetector(IM-DD)modulationisemployedandopticalpowerpenaltyafter40-kmsinglemodefiber(SMF)-28and2-mairlinkis3.2dBwithbit-error-rate(BER)at1×109.

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简介：Theeffectofλ/2SiO2overcoatonthelaserdamagecharacteristicsofHfO2/SiO2high-reflector(HR)coatingsisinvestigatedwith1-on-1andN-on-1laserdamagetestmethods.Thelaserdamagesurfaceof1-on-1isanalyzedbyastepanalyzer.ThesurfacemorphologiesshowthatlaserdamagemakesthecoatingdamagedareaprotrudentandroughforHRcoatingwithoutλ/2silicaovercoat,butconcaveandsmoothforHRcoatingwithλ/2silicaovercoat.Theresultof10-on-1multi-pulseirradiationonthesamepointofthecoatingshowsthatthereisanenergydensitystageonthedamagecurve.Ifthelaserenergydensityiswithintherangeofthestage,HfO2/SiO2HRcoatingswithλ/2silicaovercoatwillnotbedamagedmorethan2timesformulti-shots,andthesurfacedamagesareveryslightsothatthereisnoimpactonthecoatingperformance.Anotherinterestingresultisthattheenergydensitystageextendsfromthedamagethresholdtothepointofabout3timesofthreshold,whichissimilartotheeffectofthelaserconditiononcoating.

简介：Thenonlinearswitchingcharacteristicsoffusedfiberdirectionalcouplerswerestudiedexperimentally.Byusingfemtosecondlaserpulseswithpulsewidthof100fsandwavelengthofabout1550nmfromasystemofTi:sapphirelaserandopticalparametricamplifier(OPA),thenonlinearswitchingpropertiesofanullcoupleranda100%couplerweremeasured.Theexperimentalresultswerecoincidentwiththesimulationsbasedonnonlinearpropagationequationsinfiberbyusingsuper-modetheory.Nonlinearlossinfiberwasalsomeasuredtogettheinjectedpoweratthecoupler.Afterdeductingthenonlinearlossandinputefficiency,thenonlinearswitchingcriticalpeakpowersfora100%andanullfusedcouplerswerecalculatedtobe9410and9440W,respectively.ThenonlinearlossparameterPNinanexpressionofαNL=αP/PNwasobtainedtobePN=0.23W.

简介：在LD端面抽运的Nd：YVO4激光器中插入Cr^4＋：YAG晶体，获得了稳定的1．06μm波长的高重复率被动调Q脉冲激光输出。实验研究了抽运功率、腔长、输出镜透过率对输出功率的影响，以及不同抽运功率下脉冲重复频率和脉冲宽度的变化，并对结果进行了理论分析。当腔长为8cm，抽运功率为27W时，得到重复率37．8kHz、平均功率3．5W的调Q脉冲序列；单个脉冲能量为93μJ、脉宽为24ns、峰值功率为3．9kW。

简介：Thepotentialenergycurves(PECs)ofBOmolecule,includingΣ+andΠsymmetrieswithdoubletspinmultiplicities,areobtainedemployingmulti-referenceconfigurationinteraction(MRCI)methodandDunning'scorrelationconsistentbasissets.Theanalyticalpotentialenergyfunctions(APEFs)arefittedusingtheMurrell-Sorbie(MS)functionandtheleastsquaremethod.BasedonthePECs,thespectroscopicconstantsofthestateshavebeendeterminedandcomparedwiththetheoreticalandexperimentalresultsavailabletoaffirmtheaccuracyandliabilityofthecalculations.Theroot-mean-square(RMS)errorsbetweenthefittedresultsandtheabinitiovaluesaretoolittleincomparisonwiththechemicalaccuracy(349.755cm-1).ItisshownthatthepresentAPEFsareaccurateandcandisplaytheinteractionbetweentheatomswell.ThepresentAPEFscanbeusedtoconstructmorecomplicatedAPEFordosomedynamicinvestigations.

简介：Usingamicrowavegenerator,chlorinedilutedbyheliumwasdissociatedtochlorineatomsthatsubse-quentlyreactedwithhydrogenazidetoproducetheexcitedstatesofNCl(a1△).Meanwhile,moleculariodinewithcarriergasofheliumreactedwithatomicchlorinetoproduceatomiciodinewhichthenwaspumpedtoexcitedstateofI(2P1/2)byanenergytransferreactionfromNCl(a1△).Inthispaper,thechangesofNCl(a1△)andNCl(bi∑)emissionintensityispresentedwhenI2/HeisintroducedintothestreamofCl/Cl2/He/HN3/NCl(a1△)/NCl(b1∑).ThedependencesofatomiciodineI(2P1/2)onflowratesofgaseswerealsoinvestigated.TheoptimumparametersforI(2P1/2)productionaregiven.

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简介：FourkindsofY2O3stabilizedZrO2(YSZ)thinfilmswithdifferentY2O3contents(from0to12mol%)aredepositedonBK7glasssubstratesbyelectron-beamevaporationmethod.TheeffectsofdifferentY2O3dopantcontentsonresidualstress,structure,andopticalpropertiesofZrO2thinfilmsareinvestigated.TheresultsshowthatresidualstressinYSZthinfilmsvariesfromtensiletocompressivewiththeincreaseofY2O3molarcontent.TheadditionofY2O3isbeneficialtothecrystallizationofYSZthinfilmandtransformationfromamorphoustohightemperaturephase,andtherefractiveindexdecreaseswiththeincreaseofY2O3molarcontent.Moreover,thevariationsofresidualstressandtheshiftsofrefractiveindexcorrespondtotheevolutionofstructuresinducedbytheadditionofY2O3.

简介：在比较不同探月任务取得的月表三维影像数据的基础上，选择中国嫦娥一号全月分幅数字高程模型（DEM）数据作为构建月表地形模型的数据源，并利用ArcGIS、Cass和AutoCAD等软件的功能及其之间的连接关系，研究了基于月球探测数据构建月表三维模型的技术和方法。以月表撞击坑Lichtenberg为例，建立了撞击坑的三维地形模型，并对其精度和影响精度的因素进行了分析。分析结果表明，对于500m分辨率的原始数据，模型误差较小，产生误差的原因主要包括生成等高线的密度、采点间距等因素。

简介：ACe3+tion-dopedα-NaYF4singlecrystalofhighqualityisgrownsuccessfullybyanimprovedfluxBridgmanmethodundertheconditionsoftakingthechemicalrawcompositionofNaF:KF:YF3:CeF3inthemolarratioof30∶18∶48∶4,wheretheKFisshowntobeaneffectiveassistantflux.Thexraydiffraction,absorptionspectra,excitationspectra,andemissionspectraoftheCe3+t-dopedα-NaYF4singlecrystalaremeasuredtoinvestigatethephaseandopticalpropertiesofthesinglecrystals.TheabsorptionspectrumoftheCe3+t:α-NaYF4showsastrongbandthatpeaksatthewavelengthof300nm.TheemissionspectrumoftheCe3+t:α-NaYF4emitsanintenseultraviolet（UV）bandatthewavelengthof332nmundertheexcitationof300nmlight.Twoseparatedluminousbandsof330and350nm,whichcorrespondtothetransitions5d→2F25∕2and5d→F7∕2,canbeobtainedbyGaussfitting.ThestrongemissionintensityattheUVbandandtheexcellentopticaltransmissionintherangeofUVwavelengthsindicatethatCe3+t:α-NaYF4singlecrystalscanbeconsideredasapromisingmaterialforUVlasers.

简介：研究了SOFRADIR288×4红外探测器的结构与工作原理,在此基础上提出了基于外同步的288×4红外传感器的设计方案,并着重分析了其成像电路的设计,对其中的奇偶校正电路、非均匀性校正电路进行了详细的探讨和研究.

简介：Diode-pumpedpassivelyQ-switchedNd:GdVO4/Cr4+:YAGlaserswithasimpleflat-flatcavityweredemonstrated.Themaximumaverageoutputpowerat1.06μmwas1.25W.Thehighestpeakpowerandpulseenergywere7.56kWand75μJ,respectively,withthepulserepetitionrateof11.1kHzandpulsewidthof10nsattheincidentpumppowerof8W.

简介：前不久，美国化学协会的《化学与工程新闻》杂志邀请哥伦比亚大学、加州理工学院和德州大学的14名化学专家撰文，对未来25年化学领域的发展方向进行展望。

简介：Ag-MgF2cermetfilmswithdifferentAgfractionswerepreparedbyvacuumevaporation.Themicrostruc-tureofthefilmswasexaminedbyRamanscatteringtechnique.Thesurface-enhancedRamanspectrumforMgF2moleculesinthecermetfilmstronglysuggeststheexistenceofAgnanoparticlesdispersedinMgF2matrix.TheintensitiesoftheRamanspectraofAg-MgF2cermetfilmsincreasewithAgfraction.TheenhancementofRamanscatteringdisappearswhenAgcontentreacheswt.20%.TheanalyseswiththetransmissionelectronmicroscopyshowedthatAg-MgF2cermetfilmsaremainlycomposedofamor-phousMgF2matrixwithembeddedfaced-center-cubicAgnanoparticles.Itsuggeststhatthepercolationthresholdshouldbearoundwt.20%ofAgcontent.

简介：Nitridatedβ-Ga_2O_3(100)substratewasinvestigatedasthesubstrateforGaNepitaxialgrowth.Theeffectsofnitridationtemperatureandsurfaceroughnessofβ-Ga_2O_3wafersontheformationofGaNwerestudied.Itwasfoundthatthemostoptimizednitridationtemperaturewas900°C,andhexagonalGaNwithpreferredorientationwasproducedonthewell-polishedwafer.Thenitridationmechanismwasalsodiscussed.

简介：AprototypeRamanlidarwasdesignedformonitoringtroposphericCO_2profileandotherscientificin-vestigations.ThethirdharmonicofNd:YAGlaser(354.7-nmwavelength)wasusedasstimulatedlightsourcetoprovidenighttimemeasurements.FilterwithhighrejectionratioperformancewasusedtoextractCO_2RamansignalsfromRayleigh-Miescatteringsignalseffectively.Toimprovetherealtimemonitoringfunction,atwo-channelsignalcollectionsystemwasdesignedtocollectCO_2andN_2Ramanscatteringsig-nalssimultaneously.TheN_2Ramanscatteringsignalswereusedtoretrieveaerosolextinctioncoefficient.TypicalfeaturesofCO_2concentrationprofileandaerosolextinctioncoefficientinHefeiwerepresented.ThemixingratioofatmosphericCO_2inHefeicanreachabout360-400ppmv.

简介：采用HCl与NH2·H2O分步催化制各了SiO2胶体，在同一终点pH值下可得到不同的粒度,用静电自组装法制各了PDDA／SiO2有机／无机多层复合光学增透薄膜。用TEM测试了薄膜的微观结构，用721分光光度计监测了薄膜的透射率，研究了薄膜的光学性能随薄膜层数及波长的变化。

简介：1905年爱因斯坦首次提出＂光量子＂概念,标志着＂量子光学＂诞生,并有力推动其后＂量子力学＂的创建。本文将简述＂光量子＂如何诞生,＂光子＂有何奇异特性,着重介绍＂光子＂在量子信息领域的应用,包括量子密码、量子纠缠网络、量子模拟、量子计量和量子计算等。最后研讨＂光子究竟是什么＂。