Subsampled STEM-ptychography
Ptychography has been shown to be an efficient phase contrast imaging technique for scanning transmission electron microscopes (STEM). STEM-ptychography uses a fast pixelated detector to collect a “4-dimensional” dataset consisting of a 2D electron diffraction pattern at every probe position of a 2D...
| Prif Awduron: | , , , , , , |
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| Fformat: | Journal article |
| Iaith: | English |
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AIP Publishing
2018
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| _version_ | 1826303474414911488 |
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| author | Stevens, A Yang, H Hao, W Jones, L Ophus, C Nellist, PD Browning, ND |
| author_facet | Stevens, A Yang, H Hao, W Jones, L Ophus, C Nellist, PD Browning, ND |
| author_sort | Stevens, A |
| collection | OXFORD |
| description | Ptychography has been shown to be an efficient phase contrast imaging technique for scanning transmission electron microscopes (STEM). STEM-ptychography uses a fast pixelated detector to collect a “4-dimensional” dataset consisting of a 2D electron diffraction pattern at every probe position of a 2D raster-scan. This 4D dataset can be used to recover the phase-image. Current camera technology, unfortunately, can only achieve a frame rate of a few thousand detector frames-per-second (fps), which means that the acquisition time of the 4D dataset is up to 1000× slower than the scanning speed in a conventional STEM, thereby limiting the potential applications of this method for dose-fragile and dynamic specimens. In this letter, we demonstrate that subsampling provides an effective method for optimizing ptychographic acquisition by reducing both the number of detector-pixels and the number of probe positions. Subsampling and recovery of the 4D dataset are shown using an experimental 4D dataset with randomly removed detector-pixels and probe positions. After compressive sensing recovery, Wigner distribution deconvolution is applied to obtain phase-images. Randomly sampling both the probe positions and the detector at 10% gives sufficient information for phase-retrieval and reduces acquisition time by 100×, thereby making STEM-ptychography competitive with conventional STEM. |
| first_indexed | 2024-03-07T06:03:15Z |
| format | Journal article |
| id | oxford-uuid:ecefff09-6f76-4e87-88a8-32ba900bd8d8 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T06:03:15Z |
| publishDate | 2018 |
| publisher | AIP Publishing |
| record_format | dspace |
| spelling | oxford-uuid:ecefff09-6f76-4e87-88a8-32ba900bd8d82022-03-27T11:21:22ZSubsampled STEM-ptychographyJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:ecefff09-6f76-4e87-88a8-32ba900bd8d8EnglishSymplectic ElementsAIP Publishing2018Stevens, AYang, HHao, WJones, LOphus, CNellist, PDBrowning, NDPtychography has been shown to be an efficient phase contrast imaging technique for scanning transmission electron microscopes (STEM). STEM-ptychography uses a fast pixelated detector to collect a “4-dimensional” dataset consisting of a 2D electron diffraction pattern at every probe position of a 2D raster-scan. This 4D dataset can be used to recover the phase-image. Current camera technology, unfortunately, can only achieve a frame rate of a few thousand detector frames-per-second (fps), which means that the acquisition time of the 4D dataset is up to 1000× slower than the scanning speed in a conventional STEM, thereby limiting the potential applications of this method for dose-fragile and dynamic specimens. In this letter, we demonstrate that subsampling provides an effective method for optimizing ptychographic acquisition by reducing both the number of detector-pixels and the number of probe positions. Subsampling and recovery of the 4D dataset are shown using an experimental 4D dataset with randomly removed detector-pixels and probe positions. After compressive sensing recovery, Wigner distribution deconvolution is applied to obtain phase-images. Randomly sampling both the probe positions and the detector at 10% gives sufficient information for phase-retrieval and reduces acquisition time by 100×, thereby making STEM-ptychography competitive with conventional STEM. |
| spellingShingle | Stevens, A Yang, H Hao, W Jones, L Ophus, C Nellist, PD Browning, ND Subsampled STEM-ptychography |
| title | Subsampled STEM-ptychography |
| title_full | Subsampled STEM-ptychography |
| title_fullStr | Subsampled STEM-ptychography |
| title_full_unstemmed | Subsampled STEM-ptychography |
| title_short | Subsampled STEM-ptychography |
| title_sort | subsampled stem ptychography |
| work_keys_str_mv | AT stevensa subsampledstemptychography AT yangh subsampledstemptychography AT haow subsampledstemptychography AT jonesl subsampledstemptychography AT ophusc subsampledstemptychography AT nellistpd subsampledstemptychography AT browningnd subsampledstemptychography |