Electron fourier ptychography for phase reconstruction.

Area of Science:

• Materials Science
• Microscopy
• Crystallography

Background:

• Exit wavefunction reconstruction is crucial for structural analysis in transmission electron microscopy (TEM).
• Existing methods may face limitations with beam-sensitive or radiation-resistant materials.

Purpose of the Study:

• To introduce and demonstrate electron Fourier ptychography for high-resolution phase reconstruction.
• To provide an accessible alternative for structural studies using TEM.

Main Methods:

• Utilized electron Fourier ptychography with a modified iterative phase retrieval algorithm.
• Collected data in an alternative optical geometry.
• Applied the method to both radiation-resistant and beam-sensitive materials, including Cry11Aa protein crystals.

Main Results:

• Achieved high-resolution phase reconstruction of the exit wave.
• Demonstrated a spatial resolution of 0.63 nm at a fluence of 4.5 × 10^2 e-/nm^2.
• Validated the method on Cry11Aa protein crystals under cryogenic conditions.

Conclusions:

• Electron Fourier ptychography offers a broadly accessible approach for structural studies.
• The method requires no instrumental modifications and integrates seamlessly with existing software.
• Successfully applied to reconstruct phase information for diverse materials.