High-contrast imaging for weakly diffracting specimens in coherent diffraction imaging

(整期优先)网络出版时间:2013-02-12
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Coherentdiffractionimaging(CDI)andptychographytechniquesbypassthedifficultyofhavinghigh-qualityopticsinX-raymicroscopybyusinganumericalreconstructionoftheimagethatisobtainedbyinvertingthediffractedintensityrecordedbyacharge-coupleddevicearray.However,thereconstructionoftheimagefromtheintensitydataobtainedfromaweaklydiffractingspecimenisknowntobedifficultbecauseoftheobviousreductioninsignal-to-noiseratio(SNR).Inthiscase,thespecimenonlyslightlymodifiestheprobediffractionpattern,resultingindifficultyintheidentificationofthedetailedstructureofthespecimenfromthereconstructedimagebecauseofthepoorcontrastandsharpnessoftheimage.Toaddressthissituation,amodificationintheimageretrievalalgorithmsusedintheiterativereconstructionoftheimageissuggested.Thismodificationshoulddoublethepresenceofhighspatialfrequenciesinthediffractionpatterntoenhancethecontrastandedgedetectioninexistingimagingtechniques.