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arXiv · 2605.21944

Cathodoluminescence Wavefront Retrieval

Izzah Machfuudzoh·Ryoichi Horisaki·Takumi Sannomiya
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Abstract

Free-electron-based nanoscopy enables the study of optical excitations in materials with deep-subwavelength spatial resolution, with cathodoluminescence (CL) being one of the resulting radiation signals. When combined with an optical collection system, CL measurements can access multidimensional information of light; yet the phase of the emitted optical fields has remained largely elusive. Here, we demonstrate a reference-free phase retrieval approach for far-field CL wavefronts using the Gerchberg-Saxton algorithm implemented with real-space and angular-space CL intensity data. Applying this approach to representative nanostructures, including a planar surface, nanosphere, plasmonic crystal, and nanowire, we reconstruct distinct phase distributions that reveal their underlying radiation mechanisms. This reference-free framework offers a robust and flexible route for retrieving the phase of electron-beam-excited optical fields without relying on a reference wave, making it readily extendable to a wide range of nanostructures.

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Izzah Machfuudzoh, Ryoichi Horisaki, Takumi Sannomiya. 2026-05-21. Cathodoluminescence Wavefront Retrieval. https://arxiv.org/abs/2605.21944

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