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There is today a growing need to accurately model the angular scattering response of metasurfaces for optical analog processing applications. However, the current metasurface modeling techniques are not well suited for such a task since…

Optics · Physics 2023-01-04 Karim Achouri , Olivier J. F. Martin

The sharp increasing in fabrication capabilities of nanomaterials, and complex structures such as meta-surfaces and metalens, has opened to the possibility of employing them for accurately control the electromagnetic field, beyond the…

Numerical Analysis · Mathematics 2026-03-17 Vincenzo Mottola , Luisa Faella , Carlo Forestiere , Antonello Tamburrino

Bilevel optimization is a powerful tool for many machine learning problems, such as hyperparameter optimization and meta-learning. Estimating hypergradients (also known as implicit gradients) is crucial for developing gradient-based methods…

Optimization and Control · Mathematics 2025-05-06 Youran Dong , Junfeng Yang , Wei Yao , Jin Zhang

In the present work we discuss a possibility to build an instrument with two operation modes - spectral and imaging ones. The key element of such instrument is a dispersive and filtering unit consisting of two narrowband volume-phase…

Instrumentation and Methods for Astrophysics · Physics 2017-05-16 Eduard R. Muslimov , Sergei N. Fabrika , Gennady G. Valyavin

Rigorous simulations challenge recent claims that metalenses outperform conventional diffractive lenses, such as Fresnel Zone Plates (FZPs), in focusing efficiency at high numerical apertures (NAs). Across various lens diameters, FZPs…

Spatial filtering of optical fields has widespread applications ranging from beam shaping to optical information processing. However, conventional spatial filters are bulky and alignment-sensitive. Here, we present nonlocal non-Hermitian…

Optics · Physics 2025-08-04 Biao Chen , Mikael Reichler , Radoslaw Kolkowski , Andriy Shevchenko

Metasurface anomalous reflectors can enhance future wireless communication systems due to their ability to redirect electromagnetic waves and establish metasurface-assisted communication links. However, metasurface reflectors typically…

Applied Physics · Physics 2024-12-02 Vasileios G. Ataloglou , George V. Eleftheriades

Beyond the scope of space-coding metasurfaces, space-time digital metasurfaces can substantially expand the application scope of digital metamaterials in which simultaneous manipulation of electromagnetic waves in both space and frequency…

Applied Physics · Physics 2020-10-28 Javad Shabanpour

Refraction represents one of the most fundamental operations that may be performed by a metasurface. However, simple phasegradient metasurface designs suffer from restricted angular deflection due to spurious diffraction orders. It has been…

Classical Physics · Physics 2017-06-13 Guillaume Lavigne , Karim Achouri , Viktar Asadchy , Sergei Tretyakov , Christophe Caloz

Recently, metamaterials-inspired diffraction gratings (or metagratings) have demonstrated unprecedented efficiency in wavefront manipulation by means of relatively simple structures. Conventional one-dimensional (1D) gratings have a profile…

With the rising popularity of virtual worlds, the importance of data-driven parametric models of 3D meshes has grown rapidly. Numerous applications, such as computer vision, procedural generation, and mesh editing, vastly rely on these…

Computer Vision and Pattern Recognition · Computer Science 2024-02-19 Robert Kosk , Richard Southern , Lihua You , Shaojun Bian , Willem Kokke , Greg Maguire

Recent advances in holography, wireless sensing and light fidelity technologies have resulted in the need for antennas that can support highly efficient beam directivity for a broad angular range. Transmitarrays have been shown to be…

Optics · Physics 2017-11-07 Nikolaos Vasilantonakis , Jacob Scheuer , Amir Boag

Metasurfaces are planar optical elements that hold promise for overcoming the limitations of refractive and conventional diffractive optics1-3. Dielectric metasurfaces demonstrated thus far4-10 are limited to transparency windows at…

We consider blind ptychography, an imaging technique which aims to reconstruct an object of interest from a set of its diffraction patterns, each obtained by a local illumination. As the distribution of the light within the illuminated…

Numerical Analysis · Mathematics 2023-06-16 Oleh Melnyk

Printed circuit metasurfaces have attracted significant attention in the microwave community for their versatile wavefront manipulation capability. Despite their promising potential in telecommunications and radar applications, few…

Applied Physics · Physics 2021-04-08 Andreas E. Olk , Pierre E. M. Macchi , David A. Powell

Metasurfaces, the two-dimensional counterpart of metamaterials, have caught great attention thanks to their powerful capabilities on manipulation of electromagnetic waves. Recent times have seen the emergence of a variety of metasurfaces…

We present a new scheme of a moderate-resolution spectrograph based on a cascade of serial holographic gratings each of which produces an individual spectrum with a resolution of about 6000 and a bandwidth of 80 nm. The gratings ensure…

Instrumentation and Methods for Astrophysics · Physics 2017-01-04 E. R. Muslimov , N. K. Pavlycheva , G. G. Valyavin , S. N. Fabrika

The diffraction contrast modalities accessible by X-ray grating interferometers are not imaged directly but have to be inferred from sine like signal variations occurring in a series of images acquired at varying relative positions of the…

Instrumentation and Detectors · Physics 2021-02-01 Jonas Dittmann , Andreas Balles , Simon Zabler

Engineering and optimization of wireless propagation channels will be one of the key elements of future communication technologies. Metasurfaces may offer a wide spectrum of functionalities for passive and tunable reflecting devices,…

Applied Physics · Physics 2023-02-16 Sergei Kosulnikov , Xuchen Wang , Sergei A. Tretyakov

Metasurfaces are artificial thin materials that achieve optical thickness through thin geometrical structure. This feature of metasurfaces results in unprecedented benefits for enhancing the performance of optoelectronic devices. In this…

Optics · Physics 2023-08-14 Ryosuke Nakayama , Sohei Saito , Takuo Tanaka , Wakana Kubo