学科分类
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5 个结果
  • 简介:Byusingasphericalwaveasthereferencewave,werecordedthein-linephase-shiftingdigitalhologramofthe25thelementofChinesestandardNo.3resolutiontestpattern,andgavethecorrespondingnumericalreconstructedresults.Someproblemsconcerningwiththedigitalhologramrecordingandreconstructionofthediffractiveobjectatashortdistancearediscussed.Theexperimentalresultshowsthattheresolutionofthereconstructedimageisbetterthan10μm,whichisthelimitbyusingthisexperimentalarrangement.

  • 标签: 球形波 衍射物体数字全息图 全息光学 非线性位相转换数字全息图 图像重建
  • 简介:Anopticalfibersensorforultrathinlayersensingbasedonshort-rangesurfaceplasmonpolariton(SRSPP)isproposed,andthesensingcharacteristicsaretheoreticallyanalyzed.Simulationresultsindicatethatevenforadetectinglayermuchthinnerthanthevacuumwavelength,aresolutionashighas3.7×10-6RIUcanbeobtained.Moreover,anaveragethickness-detectionsensitivityof6.2dB/nmisobtained,whichenablesthesensortodetectthethicknessvariationoftheultrathinlayeruptotensofnanometers.Thesensitiveregionofthicknesscouldbeadjustedbytuningthestructureparameters.

  • 标签: 光纤传感器 表面等离激元 短程 元模式 检测灵敏度 基础
  • 简介:Inaccordancewithnonperturbativequantumscatteringtheory,weinvestigatephotoelectronangulardistributions(PADs)fromabove-thresholddetachment(ATD)ofnegativeionsirradiatedbycircularlypolarizedfew-cyclelaserfields.Electronsejectedonthepolarizationplanedemonstratedistinctanisotropiesinangulardistributionswhichdistinctlyvarywiththecarrier-envelope(CE)phase.Theanisotropyiscausedbyinterferencebetweentransitionchannels;italsodependsstronglyonlaserfrequency,pulseduration,andkineticenergyofphotoelectrons.Optimalemissionofphotoelectrons,whichvarieswithCEphase,makesitpossibletocontrolphotoelectronmotion.

  • 标签: 激光场 负离子 周期 门槛 圆极化 光电子发射
  • 简介:Thebehaviorofpopulationtransferinanexcited-doubletfour-levelsystemdrivenbylinearpolarizedfew-cycleultrashortlaserpulsesisinvestigatednumerically.Itisshownthatalmostcompletepopulationtransfercanbeachievedevenwhentheadiabaticcriterionisnotfulfilled.Moreover,therobustnessofthisschemeintermsoftheRabifrequenciesandchirpratesofthepulsesisexplored.

  • 标签: 激光技术 脉冲技术 超短波周期 频率检测
  • 简介:Er~(3+)-dopedphosphor-telluriteglassforbroadbandshort-lengthEr~(3+)-dopedfiberamplifier(EDFA)isfabricatedandcharacterized.Thedifferentialvalue(△T)ofonsetcrystallinetemperature(T_x)andglasstransitiontemperature(T_g)is206°C.ThestimulatedemissioncrosssectionofEr~(a+)iscalculatedfromab-sorptionspectrumbyMcCumbertheoryandis0.87×10~(-20)cm~2at1532nm.Abroad1.5-μmfluorescencespectrumwith54-nmfull-widthathalfmaximum(FWHM)isdemonstrated.Especially,themaximumphononenergyofundopedphosphor-telluriteglassis1100cm~(-1),whichrestrictstheupconversionlumines-cence.Itispossibletopumpefficientlyat980nm.TheseresultsindicateEr~(3+)-dopedphosphor-telluriteglassissuitableforfabricatingbroadbandshort-lengthEDFA.

  • 标签: 无机发光材料 亚碲酸盐 玻璃 短距离光线放大器