High-speed computational imaging achieved by fly-scan ptychography

Area of Science:

• Computational imaging
• X-ray microscopy
• Diffractive imaging

Background:

• Ptychography is a powerful computational imaging technique for reconstructing objects and illumination fields.
• Scanning-based ptychography faces speed limitations due to sample positioning overhead.
• Fly-scan ptychography enhances acquisition speed but introduces motion blur, requiring precise trajectory knowledge.

Purpose of the Study:

• To develop a novel ptychographic forward model for simultaneous reconstruction of object, probe, and fly-scan trajectory.
• To eliminate the need for precise synchronization and prior knowledge of the sample path in fly-scan ptychography.
• To improve reconstruction quality and reduce experimental complexity in high-flux imaging scenarios.

Main Methods:

• A modified ptychographic forward model utilizing automatic differentiation.
• Simultaneous reconstruction of object, probe, and fly-scan trajectory directly from diffraction data.
• Validation through numerical simulations and experimental measurements.

Main Results:

• Accurate retrieval of fly-scan trajectories over extended scan lengths was achieved.
• Reconstruction quality significantly improved compared to spline-interpolated paths.
• Retrieved trajectories showed good agreement with independently measured ground-truth paths.
• Diffraction-limited resolution was attained.

Conclusions:

• The developed method enables direct, synchronization-free reconstruction of fly-scan trajectories.
• This approach reduces experimental complexity and cost, making fly-scan ptychography more accessible.
• It facilitates the integration of fly-scan capabilities into conventional ptychography setups.