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Metasurface-based optical beam scanning devices are gaining attention in optics and photonics for their potential to revolutionize light detection and ranging systems. However, achieving anomalous refraction with perfect efficiency (>99%) remains challenging, limiting the efficiency and field of view (FOV) of metasurface-based optical beam scanning devices. Here, we introduce a paradigm for achieving perfect anomalous refraction by augmenting longitudinal degrees of freedom arousing a multiple scattering process to optimize symmetry breaking. An all-dielectric quasi-three-dimensional subwavelength structure (Q3D-SWS), composed of a purposely designed multilayer film and a dielectric metasurface separated by a spacer, is proposed to eliminate reflection loss and spurious diffraction, achieving >99% anomalous refraction efficiency. By independently rotating two cascaded Q3D-SWSs, we experimentally showcase half-space optical beam scanning, achieving a FOV of 144° × 144°, with a maximum efficiency exceeding 86%. Our results open new avenues for high-efficiency metasurfaces and advances applications in light detection and ranging systems.
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http://dx.doi.org/10.1038/s41467-025-58502-1 | DOI Listing |
J Ultrasound
August 2025
Emeritus Professor of Radiology, University of Genoa, Genoa, Italy.
Although easily performed and with optimal clinical results, scrotal ultrasound examinations are not free from technical difficulties. Some artifacts are relatively frequent, their creation mechanisms are well known and are easily recognized; others are uncommon, produce images which can be difficult to recognize, and need modifications of scan planes and examination techniques to be properly understood. The aim of this paper is to describe some rare artifacts and pitfalls in scrotal ultrasound, trying to explain their genesis and how to avoid them.
View Article and Find Full Text PDFPhilos Trans A Math Phys Eng Sci
August 2025
School of Informatics, Aristotle University of Thessaloniki, Thessaloniki, Greece.
Semi-analytical and numerical methods based on integral equations constitute powerful mathematical tools for the modelling and computational analysis of periodic structures. Specifically, concerning all-dielectric isotropic gratings, integral-equation methods can provide accurate solutions in an efficient manner and within a limited computational time. To this end, they can prove particularly useful in optimizations of the grating's parameters to achieve desired operational functionalities like, e.
View Article and Find Full Text PDFLiquid-core fibers, which are hollow core fibers or capillaries filled with liquids as core materials, have been attractively explored for various applications, especially in nonlinear optofluidics. High nonlinear refractive indices of selected liquids enable broadband supercontinuum generation. Unlike solid glasses, the nonlinear properties of liquids are more complex, including a contribution of electro-bound (instantaneous) nonlinearity and molecular rotation and vibration under external laser pulses (i.
View Article and Find Full Text PDFThis study presents an extensive evaluation of the accuracy of the anomalous diffraction approximation in modeling light scattering by small particles, covering a broad range of particle sizes and refractive indices typical of biological systems. To the best of our knowledge, no comprehensive study has assessed the approximation's accuracy across multiple relevant optical scattering parameters for biological particles. We present detailed maps that highlight the relative error of the anomalous diffraction approximation across various particle scattering calculations.
View Article and Find Full Text PDFPurpose: To describe previously unreported ocular manifestations associated with a de novo variant and emphasise their diagnostic significance in related disorder.
Methods: A two month old boy underwent comprehensive ocular assessment (cycloplegic refraction, slit lamp biomicroscopy, axial length, and fundus imaging), full field and multifocal electroretinography, high resolution orbital MRI, and renal ultrasonography. Trio whole genome sequencing (WGS) was performed to identify pathogenic variants.