简介：Atemperaturesensorbasedonpolarizationnon-reciprocity(PNR)infiber-opticSagnacinterferometer(FSI)wasproposed.Theexperimentalstudywasmadeprimarilyandtheresultsagreewiththeorywell.Discussionshowsthatthiskindoftemperaturesensorcanachievehighprecisionandhavegreatapplicationpotential.

简介：ThisLetterreportstheformationofperiodicsurfacestructuresonNi–Fefilmirradiatedbyasinglefemtosecondlaserpulse.Aconcavelenswithafocuslengthof-150mmisplacedinfrontofanobjective(100×,NA=0.9),whichtransformstheGaussianlaserfieldintoaringdistributionbytheFresneldiffraction.Periodicripplesformontheablationareaaftertheirradiationofasinglefemtosecondlaserpulse,whichdependsonthelaserpolarizationandlaserfluence.Weproposethattheringstructureofthelaserfieldleadstoasimilartransientdistributionofthepermittivityonthesamplesurface,whichfurtherlaunchesthesurfaceplasmonpolaritons.Theinteractionoftheincidentlaserwithsurfaceplasmonpolaritonsdominatestheformationofperiodicsurfacestructures.

简介：Thetime-of-flightmassspectrum(TOFMS)relativetotheresonanttwo-photonionizationofgasphasep-dichlorobenzenewasobtainedinthewavelengthrangeof240-250nmbyahome-madesystem.Aspecialdesignwasmadetoreducetheeffectofmemoryontheinnerwallofthesampleinletsystemsuitablefortheinvestigationofsemi-volatileorganiccompound.Inthiswavelengthrange,p-dichlorobenzenemoleculesfirstlyabsorbedonephotontobeexcitedfromthegToundstate~1A_g(S_0)tothefirstexcitedstate1B2u($1),thenabsorbedanotherphotontobeionized.Therelationshipbetweenthesignalintensityofp-dichlorobenzenemolecularionC_6H_4~(35)Cl_2~+at248-nmwavelengthandthelaserpowerwasgiven.The1.52powerindexofC_6H_4~(35)Cl_2~+wasatypicalidentificationofthe3/2powerlaw.TherelationshipbetweentheionsignalintensityofC_6H_4~(35)Cl_2~+andthesampleconcentrationwasclosetoalinearoneintheppm(V/V)range,whichledtoadetectionlimitof125ppb(V/V)forp-dichlorobenzene.

简介：温度漂移对水听器系统输出的影响是其实用化进程中的关键技术障碍。这主要表现在温度变化引起水听器探头背衬材料的胀缩和光纤折射率的变化。首先从弹性力学轴对称问题的准静态理论出发分析了背衬材料的应力特性，并用光弹理论及热应力理论分析了温度改变对光纤相位常数的影响，得出了温度影响干涉式光纤水听器光学相位输出的数学表达式。给出了温度变化对水听器光学相位输出影响的实验测量结果，得出了光学相位随温度变化的线性关系图，与理论计算结果吻合。

简介：提出了使用DSP对F-P腔滤波后的FBG反射谱进行信号处理的解调方案，DSP处理器不断地对测量支路和参考支路的信号进行采集、比较，从而解算出待测量的变化值。从光学原理上探讨了F-P腔用波长表示的干涉滤波函数，对光电探测器测得的信号进行反卷积模拟运算，得到了当光电探测器接收的光强度分布不是中心对称时，分别提高了0．0399nm和0．057nm的FBG反射谱，提高了光纤光栅传感器的解调精度。

简介：在机械压制法预置硬质合金WC/Co粉末的条形55Si2Mn弹簧钢上,用激光熔覆方法制备了化纤切断刀.调整熔覆层粉末配方中Al、TiC的加入量,结果表明加适量的Al粉能有效地抑制气孔,加TiC粉末能提高熔覆硬度.通过优化激光熔覆工艺参数,得到了无气孔缺陷、组织性能良好、硬度达到HV0.21250的激光熔覆层,达到了化纤切断刀的性能要求.

简介：在发动机活塞顶部采用热障涂层，不仅能隔热、降低腐蚀，还能进一步提高发动机热效率。运用已有的等离子喷涂技术在传统的陶瓷氧化物隔热层与铝合金之音溶合困难，氧化物杂质、缺陷及孔隙影响选到“冶金焙合”。为此对铝合金及镍合金粘结层之间的显微结构做了进一步的观测和探讨．

简介：Wereportontheamplificationofhigh-average-powerandhigh-efficiencypicosecondpulsesinaself-madeverylarge-mode-areaYb-dopedphotoniccrystalfiber(PCF).ThePCFwithacorediameterof105μmandacorenumericalapertureof0.05ispreparedbythesol-gelmethodcombinedwiththepowdersinteringtechnique.Thefiberamplificationsystemproducesthehighestaveragepowerof255Wata10MHzrepetitionratewitha21pspulsedurationcorrespondingtoapeakpowerof1.2MW.Thisresultexemplifiesthehigh-average-powerandhigh-peak-powerpotentialofthisspecificallydesignedfiber.

简介：通过分析F-P扫描干涉仪的工作原理,基于STC89C52RC单片机,采用PA93功率放大器驱动压电陶瓷,设计了1064nm平平腔结构的F-P扫描干涉仪。腔镜反射率为98%,精细度156,腔长0.1~100mm连续可调,对应自由光谱区1.5~1500GHz和分辨率9.65~9650MHz。压电陶瓷驱动电压和频率通过4×4矩阵键盘,可以在0~200V和1~30Hz连续可调,显示在1602液晶屏上。同时可以通过RS232串口与计算机通讯,在上位机使用LabVIEW软件界面方便地设置压电陶瓷驱动电压和频率。最后使用该F-P扫描干涉仪,对激光二极管泵浦Nd：YVO4激光器纵模进行了测量,验证了整个系统的工作性能。

简介：Byusingagraded-indexmultimodefiber(GI-MMF)witharelativelyflatindexprofileandhighrefractiveindexofthefibercore,amicroextrinsicfiber-opticFabryProtinterferometric(MEFPI)strainsensorisfabricatedthroughchemicaletchingandfusionsplicing.Higherreflectanceofthemicrocavityisobtainedduetotheless-curvedinnerwallinthecenterofthefibercoreafteretchingandhigherindexcontrastbetweentheGI-MMFcoreandair.Themaximumreflectionofthesensorisenhanced12dBthanthatobtainedbyetchingoftheEr-orB-dopedfibers.Highfringecontrastof22dBisobtained.ThestrainandtemperatureresponsesoftheMEFPIsensorsareinvestigatedinthisexperiment.Goodlinearityandhighsensitivityareachieved,withwavelength-strainandwavelength-temperaturesensitivitiesof7.82pm/μεand5.01pm/°C,respectively.