The fluence-resolution relationship in holographic and coherent diffractive imaging

Area of Science:

• Coherent X-ray imaging
• Lensless imaging techniques
• Numerical simulation

Background:

• Coherent imaging techniques are crucial for high-resolution microscopy.
• Understanding the impact of photon fluence on resolution is vital for optimizing imaging parameters.
• Lensless imaging methods like holography and coherent diffractive imaging offer alternatives to traditional microscopy.

Purpose of the Study:

• To numerically compare the fluence-resolution performance of inline near-field holography and far-field coherent diffractive imaging.
• To evaluate the impact of iterative phase retrieval on image quality under varying photon fluences.
• To determine which technique offers superior resolution for a given incident photon fluence.

Main Methods:

• Numerical experiments were conducted to simulate X-ray imaging scenarios.
• Iterative phase-retrieval algorithms were applied to reconstruct phase information from noisy, simulated data.
• The incident photon fluence on the specimen was systematically varied as the control parameter.
• Resolution was assessed for two distinct phantoms: a cell and a bitmap image.

Main Results:

• Inline near-field holography demonstrated superior resolution compared to coherent diffractive imaging across tested fluences.
• The performance advantage of holography was observed even with identical phase reconstruction procedures.
• Resolution was found to be directly dependent on the incident photon fluence for both techniques.

Conclusions:

• Inline near-field holography is a more efficient technique for achieving high resolution in lensless X-ray imaging, particularly at lower photon fluences.
• Coherent diffractive imaging requires higher photon fluences to achieve comparable resolutions to holography.
• The findings provide valuable guidance for selecting appropriate X-ray imaging techniques based on available photon flux and desired resolution.