Résumé: Single-shot hyperspectral wavefront sensing is essential for applications like spatio-spectral coupling metrology in high-power laser or fast material dispersion imaging. Under broadband illumination, traditional wavefront sensors assume an achromatic wavefront, which makes them unsuitable. We introduce a hyperspectral wavefront sensing scheme based on the Hartmann wavefront sensing principles, employing a multicore fiber as a Hartmann mask to overcome these limitations. Our system leverages the angular memory effect and limited spectral correlation width of the multicore fiber, encoding wavefront gradients into displacements and the spectral information into uncorrelated speckle patterns. This method retains the simplicity, compactness, and single-shot capability of conventional wavefront sensors, with only a slight increase in computational complexity. It also allows a tunable trade-off between spatial and spectral resolution. We demonstrate its efficacy for recording the hyperspectral wavefront cube from single-pulse acquisitions at the Apollon multi-petawatt laser facility, and for performing multispectral microscopic imaging of dispersive phase objects.

Résumé: Objective: To determine the organization of normal human choroidal arteries using a combination of laser Doppler holography (LDH) and OCT. Design: Cross-sectional clinical study. Subjects: One hundred thirty-two eyes of 74 healthy subjects. Methods: By combining images from a prototypic LDH system and from OCT, we documented the 3-dimensional disposition of choroidal arteries from their emergence from ciliary arteries to precapillary arterioles. Main Outcome Measures: Distribution, diameters, and pathways of choroidal arteries. Results: A notable intereye variability in the disposition of arteries was found, in which dominant patterns were identified. A short ciliary artery emerging within 1000 μm from the fovea was identified in 63% of eyes, giving rise to a horizontal submacular artery (SMA; mean diameter 119.7 ± 24.9 μm) oriented temporally. The detection rate of an SMA was inversely correlated with choroidal thickness, that is, SMAs were more often identified in thinner choroids. Among cases with a detectable SMA, its diameter positively correlated with choroidal thickness (P < 0.003). Long posterior ciliary arteries were identified in 43% of eyes and emerged at a mean distance of 4820 ± 1567 μm temporal to the fovea (mean diameter 115 ± 41 μm). Paraoptic arteries radiated from the margins of the optic nerve head, some of which perfused the macula. Disseminated axially oriented arterioles perfusing precapillary arterioles were detected from first-order arteries. Conclusions: Using a combination of LDH and OCT in healthy eyes, we identified recurrent organizational patterns of choroidal arteries in normal eyes, including SMAs, long posterior ciliary arteries, paraoptic arteries, and precapillary complexes. Characterizing the physiologic variants of the disposition of choroidal arteries helps to provide a reference framework that will enable the identification of disease-related changes. Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Résumé: Scattering of non-classical light is enabling new ways to study and control photon transport. However, advances in this field often rely on simplifying assumptions regarding the quantum light’s generation and its source. In this work, we relax some of these assumptions and probe the behavior of entangled photon pairs passing through a disordered layer after being generated by a randomly scattered pump via spontaneous parametric down-conversion. We experimentally demonstrate that when the photon pairs are generated immediately after the pump is scattered, they retain a sharp angular correlation peak even after propagating through a dynamic scattering medium. Beyond this proof-of-principle experiment, we present a comprehensive theoretical and numerical analysis showing that these correlations persist for arbitrary separations between the pair-generation region and the entrance to the disordered medium, with qualitatively distinct behavior depending on whether scattering occurs before or after pair generation. In particular, we analyze how the width and strength of the angular correlations depend on the distance between the generation region and the disordered layer. When the pairs are generated after the pump is scattered, the correlation width increases with distance, while the correlation strength remains approximately constant. In contrast, when the pairs are generated first and subsequently scattered, the correlation width initially broadens and then narrows, accompanied by a modification in correlation strength. These findings represent a crucial step toward understanding quantum light generation in complex media and potentially exploiting it for quantum technologies.