High-fidelity tabletop nanoscopy enabled by non-linear spectral preconditioning

2026-08-03

AI Summary

This work addresses the limitations of laboratory-scale ptychographic imaging, which struggles to simultaneously capture low-frequency intensity and high-frequency details due to low photon flux and limited detector bit depth. The authors propose a multiscale nonlinear fusion approach that, for the first time, demonstrates ptychographic reconstruction need not rely strictly on linear intensity assumptions, thereby overcoming conventional constraints of high dynamic range imaging. By integrating nonlinear spectral preprocessing, multiscale fusion, and a Poisson-likelihood-based phase retrieval algorithm, the method achieves robust reconstructions under strong chromatic dispersion, significantly extending the effective spectral bandwidth. This advancement enhances both the fidelity and practical diffraction-limited resolution of tabletop nanoscale imaging systems.

Abstract

Ptychography is a powerful lensless imaging technique that overcomes conventional numerical aperture limits to achieve diffraction-limited resolution. While routine at high-brilliance synchrotron facilities, its application to laboratory-scale sources is primarily limited by low photon flux. Under these conditions, the wide dynamic range of diffraction signals presents a critical bottleneck where detector bit-depth limitations hinder the simultaneous recording of low-frequency intensity and high-frequency details. Currently, most high-dynamic-range (HDR) imaging methods enforce strict radiometric linearity, assuming the fused intensity must be linearly proportional to the squared modulus of the wavefront to satisfy Poisson likelihood models. In this paper, we introduce a multi-scale non-linear fusion approach into the ptychographic pipeline, demonstrating that strict linearity is not a prerequisite for accurate reconstruction. This method mitigates the traditional trade-off between noise suppression and physical fidelity, enables robust imaging under strong dispersion, and significantly broadens the effective spectral bandwidth.

Problem

• ptychography
• high-dynamic-range
• non-linear fusion
• laboratory-scale sources
• diffraction-limited resolution

Innovation

• non-linear spectral preconditioning
• ptychography
• high-dynamic-range imaging
• tabletop nanoscopy
• multi-scale fusion