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27 个结果
  • 简介:本刊讯移动多媒体业务要求高容量,高带宽,高质量的传输方式,而目前移动通信系统效率低、费用高,容量受限,难以满足移动多媒体巨量信息的传输需求。相关国际标准均存在高昂的专利许可费。为打破国外技术垄断,依托华中科技大学、武汉汉网高技术有限公司,由朱光喜、喻莉、刘文予、邱锦波、吴伟民、冯镔等人完成的“基于IP的宽带移动多媒体通信新技术”项目提出一种“基于统计复用的全IP包交换方式”,将独占信道变为多用户动态统计复用,并通过QoS机制和资源管理,有效提高传输效率和系统容量,获得2008年湖北省技术发明一等奖。

  • 标签: 通信技术 国家实验室 动态统计复用 移动多媒体 优势 3G
  • 简介:Morethan6Waveragepowerultravioletradiationat355nmwasgeneratedinLiB3O5(LBO)crystalthroughthefrequencymixingofthefundamentalandsecondharmonicradiationofaNd:YAGlaser.Thisperformancewasachievedwith38%optical-to-opticalconversionefficiency(532nmto355nm).

  • 标签: 固体激光器 二极管泵浦 LiB3O5晶体
  • 简介:Weprovidethefirstdemonstrationofpureredemissioninthevisiblelightregionviathree-photonexcitationinmonodisperseNa_3ZrF_7:Ernanoparticles(NPs)byusingalaseroperatinginthetelecommunicationband.NPsof~22nmindiameteraresynthesizedat260°Cbythethermaldecompositionmethod.TheexperimentalresultsrevealthattheNa_3ZrF_7:ErNPsexhibitpureredemissioninthevisibleregionunder1480nmlaserexcitation,andtheemissionintensityissignificantlyinfluencedbytheEr~(3+)ionconcentration.Thedecaytimesofthe~4S_(3∕2)→~4F_(15∕2)and~4F_(9∕2)→~4F_(15∕2)transitionsoftheEr~(3+)ionsat540and655nm,respectively,arereducedbyincreasingtheEr~(3+)ionconcentrationintheNa_3ZrF_7:ErNPs.Thesuppressedemissionintensityresultfromthedefect-relatedquenchingeffect:whentrivalentEr~(3+)ionsreplactetravalentZr~(4+)ions,extraNationsandFvacanciesareformedtore-balancethechargeintheNa_3ZrF_7matrix.TheemissioncoloroftheNa_3ZrF_7:ErNPsisrelatedtothecrossrelaxationbetweenEr~(3+)ions.Theseresultsprovideanimportantsteptowardmoreeffectivebiologicalimagingandphotodynamictherapybyminimizingthescatteringoftheexcitationlightandincreasingthepenetrationdepth.

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  • 简介:Wedemonstrateadiode-pumpTm3+t-dopedall-fiberlaseroperatingat1908nmbasedonamasteroscillatorpoweramplifier(MOPA)configuration.Inourwork,152Woflaseroutputpowerisgeneratedbyatotalincidentpumppowerof434Wat790nm,correspondingtothetotalopticalefficiencyof35%.Thelaserwavelengthis1908.29nm.Tothebestofourknowledge,itisthehighestoutputpowerreachedaround1908nmwithsuchanarrowlinewidthof0.18nmbasedonaMOPAconfiguration.

  • 标签: 全光纤激光器 功率放大器 主振荡器 配置 光谱线宽 TM
  • 简介:Wereportonthecontinuous-wave(CW)andpassiveQ-switchingperformanceofaminiatureYb:Y3Ga5O12crystallaserendpumpedbya935-nmdiodelaser.AmaximumCWoutputpowerof12.03Wisproducedwithanoptical-to-opticalefficiencyof54.4%,whiletheslopeefficiencyis63%.InthepassivelyQ-switchedoperationachievedwithaCr4+:YAGsaturableabsorber,anaverageoutputpowerof2.12Wat1025.2nmisgeneratedwithaslopeefficiencyof46%atapulserepetitionrateof5.0kHz.Thepulse’senergy,duration,andpeakpowerare424μJ,2.3ns,and184.3kW,respectively.

  • 标签: 高功率连续波 晶体激光器 被动调Q 微型 最大输出功率 激光二极管抽运
  • 简介:Adiode-end-pumpedelectro-optic(EO)Q-switchedNd:YVO4laseroperatingatrepetitionrateof10kpps(pulsespersecond)wasreported.AblockofLa3Ga5SiO14(LGS)singlecrystalwasusedasaQ-switchandthedriverwasametaloxidesemiconductorfieldeffecttransistor(MOS-FET)pulserofhighrepetitionrateandhighvoltage.Atcontinuouswave(CW)operation,theslopeefficiencyofthelaserwas46%,andmaximumoptical-to-opticalefficiencywas38.5%.Usinganoutputcouplerwithtransmissionof70%,a10-kppsQ-switchedpulsetrainwith0.4-mJmonopulseenergyand8.2-nspulsewidthwasachieved,theopticalconversionefficiencywasaround15%,andthebeamqualityM2factorwaslessthan1.2.

  • 标签: Q调制Nd:YVO4激光器 La3Ga5SiO14单晶电光调制器 金属氧化物半导体 激光技术