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Conventional microwave imaging schemes, enabled by the ubiquity of coherent sources and detectors, have traditionally relied on frequency bandwidth to retrieve range information, while using mechanical or electronic beamsteering to obtain…

Analog computation with passive optical components can enhance processing speeds and reduce power consumption, recently attracting renewed interest thanks to the opportunities enabled by metasurfaces. Basic image processing tasks, such as…

Optics · Physics 2024-01-15 Sedigheh Esfahani , Michele Cotrufo , Andrea Alù

Optical metasurfaces have been enabling reduced footprint and power consumption, as well as faster speeds, in the context of analog computing and image processing. While various image processing and optical computing functionalities have…

Metasurfaces have revolutionized the design concepts for opticalcomponents, fostering an excitingfield offlat optics. Thanks to theflat and ultrathinnature, metasurfaces possess unique advantages over conventional optical components,such as…

Optics · Physics 2021-05-03 Jianxiong Li , Ping Yu , Shuang Zhang , Na Liu

As a widely used localization and sensing technique, radars will play an important role in future wireless networks. However, the wireless channels between the radar and the targets are passively adopted by traditional radars, which limits…

Signal Processing · Electrical Eng. & Systems 2023-03-27 Haobo Zhang , Hongliang Zhang , Boya Di , Kaigui Bian , Zhu Han , Lingyang Song

Phase-shifting structured illumination is a powerful technique used across diverse imaging modalities, including 3D surface measurement, quantitative phase imaging, and super-resolution microscopy. However, conventional implementations…

Optics · Physics 2025-05-05 Linzhi Yu , Jesse Pietila , Haobijam Johnson Singh , Humeyra Caglayan

Electromagnetic metasurfaces have attracted significant interest recently due to their low profile and advantageous applications. Practically, many metasurface designs start with a set of constraints for the radiated far-field, such as…

Materials Science · Physics 2022-04-04 Stewart Pearson , Parinaz Naseri , Sean V. Hum

Metasurfaces have been proposed as a new paradigm to manipulate light and improve light-matter interactions. Conventional metasurfaces are restricted to the loss of materials, limiting their performance ceiling. Here, the loss of metallic…

Optics · Physics 2023-11-02 Yisheng Gao

In this paper, a wideband and low-scattering metasurface in terahertz (THz) is introduced. The proposed coding metasurface is composed of four different graphene square patches in one layer, which has a distinct bias voltage. By optimizing…

Applied Physics · Physics 2020-01-28 Kasra Rouhi , Ali Abdolali , Susan Fallah

Non-imaging optical lenses can shape the light intensity from incoherent sources to a desired target intensity profile, which is important for applications in lighting, solar light concentration, and optical beam shaping. Their surface…

Actively tunable and reconfigurable wavefront shaping by optical metasurfaces poses a significant technical challenge often requiring unconventional materials engineering and nanofabrication. Most wavefront-shaping metasurfaces can be…

Optics · Physics 2020-08-24 Stephanie C. Malek , Adam C. Overvig , Sajan Shrestha , Nanfang Yu

Space-time modulated metasurfaces have attracted significant attention due to the additional degree of freedom in manipulating the electromagnetic (EM) waves in both space and time domains. However, the existing techniques have limited wave…

Applied Physics · Physics 2020-12-07 Jun Yan Dai , Jin Yang , Wankai Tang , Ming Zheng Chen , Jun Chen Ke , Qiang Cheng , Shi Jin , Tie Jun Cui

Photonic devices rarely provide both elaborate spatial control and sharp spectral control over an incoming wavefront. In optical metasurfaces, for example, the localized modes of individual meta-units govern the wavefront shape over a broad…

Optics · Physics 2022-01-27 Stephanie C. Malek , Adam C. Overvig , Andrea Alù , Nanfang Yu

We study parametric amplification of electromagnetic waves using metasurfaces. We design a variable capacitor-loaded metasurface that can amplify incident electromagnetic waves. We analyze various regimes of operation of the system and find…

Applied Physics · Physics 2024-02-02 Fedor V. Kovalev , Ilya V. Shadrivov

In the quest to realize analog signal processing using sub-wavelength metasurfaces, in this paper, we demonstrate the first experimental demonstration of programmable time-modulated metasurface processors based on the key properties of…

Applied Physics · Physics 2020-02-19 Hamid Rajabalipanah , Ali Abdolali , Shahid Iqbal , Lei Zhang , Tie Jun Cui

So far, the environment has been considered as a source of fading, clutter, blockage, etc., with detrimental consequences for the efficiency and robustness of communication systems. However, the intense research developed toward beyond-5G…

Metasurfaces represent one of the most vibrant fields of modern science and technology. A metasurface is a complex electromagnetic structure, that is typically deeply subwavelength in thickness, electrically large in transverse size and…

Optics · Physics 2017-11-01 Yousef Vahabzadeh , Nima Chamanara , Karim Achouri , Christophe Caloz

Physically accurate and mathematically tractable models are presented to characterize scattering and reflection properties of reconfigurable intelligent surfaces (RISs). We take continuous and discrete strategies to model a single patch and…

Systems and Control · Electrical Eng. & Systems 2022-08-31 Tiebin Mi , Jianan Zhang , Rujing Xiong , Zhengyu Wang , Robert Caiming Qiu

Metasurfaces have attracted extensive interests due to their ability to locally manipulate optical parameters of light and easy integration to complex optical systems. Particularly, metasurfaces can provide a novel platform for splitting…

In millimeter wave (mmWave) systems, it is challenging to ensure the reliable connectivity of communications due to its sensitivity to the presence of blockages. In order to improve the robustness of the mmWave system under the presence of…

Information Theory · Computer Science 2021-09-01 Gui Zhou , Cunhua Pan , Hong Ren , Kezhi Wang , Marco Di Renzo