Optical Point-Spread Function via Defocus Phase Retrieval in Scanning Electron Microscopy
Chester F. Carlson Center for Imaging Science, Rochester Institute of Technology（切斯特·F·卡尔森成像科学中心，罗切斯特理工学院）
Surya Kamal, Kevin Mogere Nyaburi, Richard K. Hailstone
备注：
Accepted for publication in Micron. Updated title and author list; revised manuscript reflects the accepted version. 9 pages, 6 figures
发表信息：
Kamal, S., Nyaburi, K. M., & Hailstone, R. K. (2026). Optical point-spread function via defocus phase retrieval in scanning electron microscopy. Micron, 104097
The point-spread function of the probe-forming optics ($PSF_{optics}$) is reported in an uncorrected (without multipole correctors) scanning electron microscope (SEM). In an SEM, information about the electron probe is generally lost as the beam interacts with the specimen. Here, we demonstrate an approach for recovering probe phase information from reconstructed probe intensity estimates. Controlled defocus was used to acquire a focal series of SEM images of $28.5,nm$ gold ($\mathrm{Au}$) nanoparticles ($\mathrm{NPs}$) on a carbon ($\mathrm{C}$) film. These images were used to reconstruct their respective probe intensities, generating a focal series of probe intensities that served as input to the phase retrieval pipeline. Using the complete description (intensity and phase) of the electron probe wavefunction at the specimen plane, we estimate the $PSF_{optics}$ for multiple data sets at a beam energy of $E = 20,keV$. These results represent an important step in demonstrating the possibility of experimental aberration quantification in uncorrected SEMs.
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National University of Singapore（新加坡国立大学）；Institute of Materials Research and Engineering, Agencies of Science, Technology and Research (A*STAR)（新加坡科技研究局材料研究与工程研究所）；NUS Research Institute (NUSRI)（新加坡国立大学研究院）
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