Extended ptychography in the transmission electron microscope: possibilities and limitations

Area of Science:

• Microscopy
• Phase Retrieval Algorithms
• Computational Imaging

Background:

• Conventional lens microscopy faces resolution limits.
• Phase retrieval algorithms are crucial for overcoming these limitations.
• The extended-ptychographical iterative engine (e-PIE) is a novel phase retrieval technique.

Purpose of the Study:

• To evaluate the performance of e-PIE in transmission electron microscopy (TEM).
• To demonstrate e-PIE's capability in reconstructing object and illumination functions simultaneously.
• To explore the possibilities and limitations of ptychography, particularly concerning probe position accuracy.

Main Methods:

• Application of the extended-ptychographical iterative engine (e-PIE) algorithm.
• Experimental validation using transmission electron microscopy.
• Supporting simulations to analyze algorithm behavior and limitations.

Main Results:

• e-PIE successfully reconstructed object and illumination functions in TEM.
• The algorithm demonstrated robustness to noise and rapid convergence.
• Simulations highlighted the potential and challenges, especially with strong phase objects and probe positioning errors.

Conclusions:

• e-PIE is a powerful tool for phase retrieval in TEM, surpassing conventional methods.
• The technique offers simultaneous reconstruction and improved performance metrics.
• Careful consideration of probe positioning is essential for optimal ptychographic results.