简介：Wepresentadigitalholographicmicroscopewhereinthesampleisilluminatedbystructuredlighttoenablethecaptureofadditionalobjectspatialfrequencies.ReconstructedimageswithincreasedspatialresolutionareobtainedbyseparatingandsynthesizingbandwidthsofdifferentfrequencyregionsintheFourierdomain.Thetheoreticalanalysisandexperimentalresultsarepresented.

简介：Byusingasphericalwaveasthereferencewave,werecordedthein-linephase-shiftingdigitalhologramofthe25thelementofChinesestandardNo.3resolutiontestpattern,andgavethecorrespondingnumericalreconstructedresults.Someproblemsconcerningwiththedigitalhologramrecordingandreconstructionofthediffractiveobjectatashortdistancearediscussed.Theexperimentalresultshowsthattheresolutionofthereconstructedimageisbetterthan10μm,whichisthelimitbyusingthisexperimentalarrangement.

简介：Basedonthepointspreadfunctionofholographicsystem,thelateralresolutionofdigitalholographicimagingsystemwithoutanypre-magnificationisstudied.Theexpressionofresolutionlimitationofholo-graphicimagingsystemisthuspresented.Weinvestigatethepossibilitiestoimprovethelateralresolution.Thesimpleexperimentalsetupwithanoff-axisarrangementisbuilt.ByusingaU.S.AirForce(USAF)testtargetasmicroscopicobject,therecordedhologramsarereconstructeddigitallybasedontheprincipleofFresneldiffraction.Thelateralresolutionof2.76μmwithoutanypre-magnifieationisdemonstratedexperimentally,whichmatchesthetheoreticalpredictionwell.

简介：Targetdynamicsareassumedtobeknowninmeasuringdigitalspeckledisplacement.Useismadeofasimplemeasurementequation,wheremeasurementnoiserepresentstheeffectofdisturbancesintroducedinmeasurementprocess.Fromtheseassumptions,Kalmanfiltercanbedesignedtoreducevarianceofmeasurementnoise.Anopticalandanalysissystemwassetup,bywhichobjectmotionwithconstantdisplacementandconstantvelocityisexperimentedwithtoverifyvalidityofKalmanfilteringtechniquesforreductionofmeasurementnoisevariance.

简介：Anintegratedmethodbasedonopticalanddigitalimageprocessingispresentedtosuppressspeckleindigitalholography.Aspatiallightmodulatorisadoptedtointroducerandomphasestotheilluminatingbeam.Multiplehologramsarereconstructedandsuperimposed,andtheintensityisaveragedtosmooththenoise.Theadaptivealgorithmbasedonthenonlocalmeansisdesignedtofurthersuppressthespeckle.Thepresentedmethodiscomparedwithothermethods.Theexperimentalresultsshowthatspecklereductionisimproved,andtheproposedmethodiseffectiveandfeasible.

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