Ptychographic reconstruction with object initialization.

Area of Science:

• Physics
• Materials Science
• Imaging Science

Background:

• X-ray ptychography is an advanced imaging technique achieving ultra-high spatial resolutions.
• Phase retrieval in ptychography recovers complex signals from intensity measurements using overlapping illumination data.
• Reconstruction speed is limited for large samples with flat initialization due to information propagation from edges to the center.

Purpose of the Study:

• To improve the computational speed of X-ray ptychography reconstructions for bulky samples.
• To mitigate phase artifacts and reduce probe phase structure requirements.
• To present an adaptable and efficient initialization strategy for ptychographic algorithms.

Main Methods:

• Experimentally demonstrating the use of a low-resolution sample wavefront as object initialization.
• Utilizing diffraction patterns from measured data to retrieve the initial sample wavefront.
• Comparing reconstruction speed and artifact generation against traditional flat initialization.

Main Results:

• A considerable improvement in computational speed was achieved using the proposed wavefront initialization.
• The wavefront initialization method effectively avoided phase artifacts associated with large phase gradients.
• The approach showed potential to alleviate stringent requirements on the phase structure of the illumination probe.

Conclusions:

• Initializing X-ray ptychography with a retrieved low-resolution sample wavefront significantly enhances reconstruction speed.
• This method is computationally efficient, avoids artifacts, and is compatible with bulky and flat samples.
• The approach is readily adaptable to existing ptychographic reconstruction algorithms, facilitating widespread adoption.