简介:Anovelfluorometerbasedonfiberopticsisbrieflyintroducedforthemeasurementofalgaconcentration.Boththeexcitinglightandthefluorescencefromalgachlorophyllaretransmittedalongafibercable.Bythisway,wecangetalgaconcentrationbymeasuringitschlorophyll-afluorescenceintensity.Theexperimentresultsshowthatthisinstrumentischaracterizedbygoodsensitivity,linearityandaccuracy.
简介:Thesecurityofcivilengineeringisanimportanttaskduetotheeconomic,socialandenvironmentalsignificance.Comparedwithconventionalsensors,theopticalfibersensorshavetheiruniquecharacteristics.Beingdurable,stableandinsensitivetoexternalperturbations,theyareparticularinterestingforthelong-termmonitoringofcivilstructures.Focusisonabsolutemeasurementopticalfibersensors,whichareemergingfromthemonitoringlargestructural,includingSOFOsystem,F-Popticalfibersensors,andfiberBragggratingsensors.Theprinciple,characteristicandapplicationofthesethreekindsofopticalfibersensorsaredescribedtogetherwiththeirfutureprospects.
简介:Atwistedfiberopticsensorbasedonintensitymodulationisdescribed.Theprincipleandstructureofthesensorandthechoiceofsteelstrandmodulesareintroduced.Thesensorisusedtodeterminethetensilestrainanddistribution.Theexperimentalresultsshowthatthechangeofthetransferringlightpowerhasanapproximatelinearrelationwiththeouterforce.Theintelligentsteelstrandswiththiskindofsensorwillhaveagoodapplicationinmonitoringtheconcretecrackanddeformationdistributioninhugestructuressuchasdamsandbridges.
简介:Themethodformeasuringthestrainofanobjectusinganopticalfiberandafrequencymodulation(FM)coupledcaritysemiconductorlaserispro-posed.ThismethodusesthecoherentFMheterodyneprincipleoftheMichelsonin-terferometerandcanavoidtheπ/2nonreciprocalphasebiasandphaseshiftingproblemexistingingeneralfiberopticinterferentialsensors,themaximumdetec-tionrangeislimitedbythecoherentlengthofthesemiconductorlaseranditsrela-tivefactor.
简介:采用1/4波浪板为阶段延迟和波浪板的眼的轴的同时的测量使用的一个简单方法被表明。测量原则的理论分析详细被介绍。在测量,在调整标准1/4以后,挥动板并且快(慢)要测量的板的轴平行到polarizer的通行证轴,要测量的板被450counterclockwisly旋转。一台步进马达被用来旋转分析器。试验性的数据被一个光电探测器收集然后送到一台计算机。根据产量数据曲线,阶段延迟和要测量的板的眼的轴能同时被获得。为了测试方法,位/2和位的可行性,/8波浪盘子被用作例子表明测量过程。阶段延迟测量精确性比0.5脳好10?2。这个方法能被用来方便地测量任意的阶段延迟。CLC数字O436.3
简介:Byaccuratelymeasuringthedisplacementbetweentherollersurfaceandtheopticalfiberproberelativetoanullposition,wecantesttherollerwear.Thewholetestingmethodandsystemwereintroduced.Eachpartofthetestingsystemwasillustrated.Andalsoanovelfiber-opticsensorwiththreeprobesinequaltransversespaceisadopted.Usingthissensor,theeffectsoffluctuationsinthelightsource,reflectivitychangingoftargetsurfaceandtheintensitylossesinthefiberlinesareautomaticallycompensated.Thismethodofferssuchadvantagesasnon-contact,noelectromagneticinterference,simplicity,lowcost,highsensitivity,goodaccuracyandstability.
简介:Anovelsystemconfigurationoffiberopticsensorbasedonopticalabsorptionisproposed.Severalcompensationmeasuresarediscussed.Asimulatedexperimentisdesignedandtheoutputcurveofsystemisgiven.Theexperimentalresultshowsthatthesecompensationmeasuresareeffectiveondynamicdisturbanceswhicharecausedbybackgroundlightandopticalfiberbend,Inaddition,thedriftsinthelightsourceintensity,fiberlosses,andphotodetectorefficiencyareaslocompensated.
简介:Parameterquantificationprincipleofthree-dimensional(3-D)fluorescentspectrumanditsrealizationtechniquearestudied.Thepotablefiberopticfluorescentmeasurerformineraloilisgiven.Threeparametersoftheexcitinglightwavelength.theeavelengthandtheintensityofthefluorescentlightexcitedbythemeasuredoilareexpressedwith3-Dcoordinatesandareprocessedsoastobesampledagainandtobecurvefitted.
简介:Thestabilityofthedrivecurrentisveryimportantforalaserdriver,whileitisdifficulttomaintainthecurrentstableatahighvalueforthelaserdriver.Ontheotherhand,therangeofthedrivecurrentisexpectedtobeaswideaspossibletobeappliedtodifferentkindsoflasers.Inthispaper,ahighcurrentlaserdriverforthesuperluminescentlightemittingdiode(SLED)ispresented,whichisusedintheopticfibergyroembeddedbya0.35mbipolarcomplementarymetal-oxide-semiconductortransistor(BiCMOS)process.Thelaserdriverprovidesautomaticpowercontrolandcertainvalueofcurrentdeterminedbytheexternalresister.Thesystemisbasedontheoptic-electricfeedbacktheoryandusestheclosed-loopcontroltechniquetomaintainthedrivecurrentstable.Thesystemiscapableofproducingstablecurrentrangesfrom4mAto200mAwhenthevalueofexternalresisterchanges.
简介:磁电机眼(瞬间)与微波magnetostatic波浪(MSW)指导光波浪联合同时由信号能导致的多重收音机频率(RF)激动RF信号的multifrequency衍射效果然后并行处理能被衍射效率(Des)是的特征使用认识到近似在里面到RF信号紧张和衍射角度的直接比例与在线性瞬间相互作用区域以内的相应RF信号的频率有关。在这份报纸,学习了是在一阶的瞬间相互作用近似的multifrequency瞬间布拉格衍射,并且获得是为原则衍射效率(PDE)的近似分析表示。另外,提出基于单个频率的衍射是RF信号的相对紧张的一个平行成像方法。由计算和分析,相对错误是为在内的三个RF信号的盒子的不超过0.3dB60MHz的频率空间,这被显示出。
简介:一个有效、灵活的旋转和赔偿计划被设计改进旋转惯性的航行系统(RINS)的精确性。单人赛轴的RINS的精确性被错误在旋转的轴上限制。有为纤维的旋转的轴的错误赔偿的一个新奇惯性的测量单位(IMU)计划眼的旋转罗盘(雾)RINS被介绍。在计划,有类似的错误特征的二对惯性的传感器在旋转斧子上相对地被装补偿传感器错误。没有为旋转周期的任何变化,这个计划改进系统精确和可靠性,并且也为系统提供冗余性。36h航行模拟的结果证明系统的精确性尤其是与正常strapdownINS相比被改进,除出发精确性以外与单人赛轴的RINS相比到3次被增加,并且位置精确性被1个数量级改进。