Quantifying the data quality of focal series for inline electron holography

Area of Science:

• Materials Science
• Physics
• Electron Microscopy

Background:

• Inline electron holography is a widely used technique for recovering electron wave function amplitude and phase.
• Accurate phase retrieval is crucial for analyzing materials at the nanoscale.
• Challenges exist in retrieving low spatial frequency information, particularly at medium magnifications.

Purpose of the Study:

• To present methods for quantitatively analyzing the reliability of phase maps obtained by inline electron holography.
• To compare data processed using different experimental parameters and normalization methods.
• To evaluate the effectiveness of regularization schemes in addressing artifacts.

Main Methods:

• Recording focal series of electron wave functions in a transmission electron microscope.
• Applying various data normalization techniques.
• Implementing and assessing regularization schemes for phase reconstruction.
• Quantitative analysis of phase map reliability.

Main Results:

• The retrieval of low spatial frequency information is sensitive to experimental parameters and data normalization.
• Even optimized inline electron holography reconstructions lack very low spatial frequency components.
• Regularization schemes effectively mitigate artifacts caused by missing low spatial frequency information.

Conclusions:

• Reliability analysis methods for inline electron holography phase maps are established.
• Careful selection of experimental parameters and normalization is vital for accurate phase retrieval.
• Regularization offers a robust solution for improving the quality of reconstructed phase maps by addressing inherent data limitations.