資源描述：
《A Laser Displacement Sensor Using the Self-Mixing Effect for Modal Analysis and Defect Detection》由會(huì)員上傳分享，免費(fèi)在線閱讀，更多相關(guān)內(nèi)容在行業(yè)資料-天天文庫(kù)。
1、IEEETRANSACTIONSONINSTRUMENTATIONANDMEASUREMENT,VOL.46,NO.4,AUGUST1997847ALaserDisplacementSensorUsingtheSelf-MixingEffectforModalAnalysisandDefectDetectionNoelServagent,ThierryBosch,andMarcLescure¨AbstractDAlow-cost,simple,noncontactdisplacementsensorusingtheself-mixingeffectinsideacwsingle-m
2、odelaserdiodehasbeendevelopedformodalanalysisanddefectdetection.Theresonancefrequenciesofthinclampedmetallicplateshavebeendeterminedwitharesolutionof0.2Hz.Withsuchtargets,classicspectrumanalyzersgenerateameasurementerrorupto10%becauseoftheweightoftheaccelerometer.Thefrequency-shiftofthefundame
3、ntalresonancefrequencybetweenastandardplateandthesameonewithaknowndefectcanalsobemeasured,themodalvectorassociatedtothisfrequencybeingdistortedattheplaceofthedefect.IndexTermsDDisplacementsensor,laserdiode,modalanaly-sis,opticalfeedback,self-mixingeffectI.IFig.1.Experimentalsetupformodalanalys
4、isofaclampedplateusinganNTRODUCTIONML64110Nlaserdiode.HEREaremanyindustrialprocessesinwhichanon-Tcontacttechniqueforvibrationsmeasurements,modalII.LASERDISPLACEMENTSENSORanalysis,ordefectdetectionwouldbenecessaryforqualitycontrolpurposesornondestructivetesting.SomeexamplesFig.1representstheblo
5、ckdiagramofanexperimentaloftheseprocessesarefabricationofmicromechanicscom-setupdevelopedfordisplacementmeasurementusingtheself-ponents,semiconductorsensors,orloudspeaker.Laser-basedmixingeffect.AcwML64110Nlaserdiodeisdrivenattechniquesgenerallyusinginterferometricsetupexistinsuchtheopticalpow
6、erof30mWandawavelengthofprocessesbuttheyareexpensive.Moreover,theyoftenneed785nm.ThelaserbeamoutputfromtheLD'srearfacetismirror-likesurfaces.monitoredbyaphotodiodewithintheLDpackage.ByusingSelf-mixinginterferenceinacwsingle-modelaserdiodearoughtarget,onecanconsiderthemultiplere?ectionwithin(LD
7、)isawell-knownlow-costopticalmethodextensivelytheexternalcavitytobeneglectedforaweakfeedback[5],usedtomeasuredistances[1],displacementsandvibrations[6].Fordistancesofthetargetsmallerthanthehalf-coherence[2]±[4].Thelaserbeamisre?ectedbya
