variation and phase-shifting capability

《variation and phase-shifting capability》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、variationandphase-shiftingcapability0PTOELECTR0NICSLETTERSVo1.3No.2,15Mar.2007All--solid--statemicroscopicinterferometerwithfrequency-variationandphase--shiftingcapability*TIANJin—dong,ZHAOXiao—bo,andPENGXiangInstituteofOptoelectronicsandKeylaboratoryofOptoe

2、lectronicDevicesandSystemsofEducationMinistry,ShenzhenUuiversity,Shenzhen518060,China(Received9January2007)Anovelmicroscopicinterferometrywithabilityof~equency-variationandphase-shiftingisproposedformicrostructurestesting.Byusingacousto-optictechnique,sequen

3、tialcarrierscanbegeneratedwithdifferentspatialfrequenciessothatthetemporalphaseunwrappingmethodcanbeappliedfordecodingtheheightinformation.Combinedwithphase-shiftingtechniquerealizedbyspatiallightmodulator,thismethodisespeciallysuitableforintefferometricmeas

4、urementwithhighprecisionandlargedynamicrange.CLCnumber:TB96Documentcode:AArticleID:l673.1905(2007')02-0123-03DOI10.1007/sl180l一007—7Ol3—3Recentdevelopmentofmicroelectromechanicalsystem(MEMS)hascreatedagreatneedford.edicatedinspectionofthemicrostructuresandde

5、vices【".Fortheseminiaturestructures,themicroscopicinterferometryplaysanimpor—tantroleinthestructuretesting.Itiswellknownthatopticalphase-shiftingisdesiredinvariousinterference-basedopti—calsystems,includinglateralshearinginterferometryI2],ho-lographicinteffe

6、rometry【.】andphasemeasuringprofilometry【4】.Opticalphase-shiflingcanbeimplementedinvariousways.Asaconventionalmethod.mechanicaltranslationscanbeachievedbyasteppingmotororapiezoelectrictransducer.Buttheaccuracy,stabilityanddynamicresponsearemainissuesintheappl

7、icationofmechanicalmethodsduetotheirinherentcharacteristicssuchashysteresisandthermaldrift【5】.Analternativemethodisdigitalphase-shiftingbasedonelectronicallyaddressedspatiallightmodulator(SLM)[6].Theadvantageofthismethodisthatthephase-shiftingcanbecontrolled

8、digitallyandnoprecisionmechanicaltranslationisrequired.Byphase-shifting,phaseevaluationcanbeperformedtoobtainawrappedphasemap.Phaseunwrappingisthereforerequiredbeforeunambiguousheightinformation