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Jun Lim

Publications and source records attributed to Jun Lim.

2 recordsLinked to original sources

Quantitative X-ray Schlieren Nanotomography for Hyperspectral Phase and Absorption Imaging

Hyperspectral X-rays imaging holds promise for three-dimensional (3D) chemical analysis but remains limited in simultaneously capturing phase and absorption information due to complex setups and data burdens. We introduce quantitative X-ray schlieren nanotomography (XSN), a simple, fast, and high-resolution X-ray phase imaging technique that overcomes these limitations. XSN employs a partially coherent illumination and a pupil-plane cutoff filter to encode directional phase contrast, enabling single-shot acquisition. A quasi-Newton iterative algorithm reconstructs quantitative phase and absorption images from intensity data, even under strong scattering conditions. Scanning across X-ray energies further allows four-dimensional imaging (3D spatial & spectral). We validate the method's accuracy and resolution on reference samples and apply it to lithium battery cathodes, visualizing nanoscale microcracks and mapping chemical compositions. XSN provides a robust framework for hyperspectral phase nanotomography with broad applicability across materials science, biology, and energy research.

physics.optics

External-cavity designs for phase-coupled laser diode arrays

We describe passive phase-locking architectures based on external-cavity setups to improve the brightness of diode laser bars. Volume Bragg gratings are used to stabilize the lase line. Numerical modelling and experimental results will be presented.

physics.optics