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Recently, a new device to measure the Orbital Angular Momentum (OAM) electronic spectrum after elastic/inelastic scattering in a transmission electron microscope has been introduced. We modified the theoretical framework needed to describe…

Instrumentation and Detectors · Physics 2020-05-28 Matteo Zanfrognini , Enzo Rotunno , Stefano Frabboni , Alicia Sit , Ebrahim Karimi , Ulrich Hohenester , Vincenzo Grillo

Orbital angular momentum (OAM) based radio vortex wireless communications have received much attention recently because it can significantly increase the spectrum efficiency. The uniform circular array (UCA) is a simple antenna structure…

Signal Processing · Electrical Eng. & Systems 2018-09-14 Shanghua Gao , Wenchi Cheng , Wei Zhang , Hailin Zhang

Accurate characterization of atmospheric optical turbulence is essential for evaluating astronomical sites and optimizing adaptive optics systems. The Multistar Turbulence Monitor (MTM) infers the vertical distribution of the…

Instrumentation and Methods for Astrophysics · Physics 2026-05-08 Weisen Huang , Bin Ma , Tengfei Song , Paul Hickson , Zhaohui Shang , Xuefei Zhang , Mingyu Zhao , Qing Zhou

We report on experimentally observed addition, subtraction and cancellation of orbital angular momentum (OAM) in the process of parametric four-wave mixing that results in frequency up- and down-converted emission in Rb vapour. Specific…

The use of a wire probe is a robust method for beam profile measurement, but it can only provide a 1D projection of the beam profile. In this study, we developed a novel method for measuring a beam projected from a 360{\deg} angle by a…

Instrumentation and Detectors · Physics 2025-09-16 Rin Ota , Nanako Nakajima , Ryuto Takemasa , Hiroya Tamaru , Yoko Shiina , Yuji Nakano

Metasurface holography has the advantage of realizing complex wavefront modulation by thin layers together with the progressive technique of computer-generated holographic imaging. Despite the well-known light parameters, like amplitude,…

Free-space optical communication is a promising means to establish versatile, secure and high-bandwidth communication for many critical point-to-point applications. While the spatial modes of light offer an additional degree of freedom to…

We characterize sets of fractional orbital angular momentum (OAM) modes of a light beam using unitary-invariant properties encoded by two-mode overlaps. Using basis-independent coherence and dimension witnesses, we experimentally certify,…

The subject area of free space optical communication with optical beam carrying orbital angular momentum has attracted a great deal of research attention since last two decades. Efforts to understand, model and execute communication links…

Optics · Physics 2023-08-03 Shakti Singh , Sanjay Kumar Mishra , Akhilesh Kumar Mishra

Atmospheric turbulence in long-range imaging significantly degrades the quality and fidelity of captured scenes due to random variations in both spatial and temporal dimensions. These distortions present a formidable challenge across…

Computer Vision and Pattern Recognition · Computer Science 2024-10-02 Zhicheng Zou , Nantheera Anantrasirichai

Optical interferometry has dramatically advanced the development of modern science and technology. Here we introduce an interesting centroid evolution phenomenon of orbital angular momentum (OAM) interference fields with broken rotational…

Optics · Physics 2025-01-29 Liang Fang , Jinman Chen , Qinjun Chen , Chujun Zhao

The orbital angular momentum (OAM) technique provides a new degree of freedom for information transmissions in millimeter wave communications. Considering the spatial distribution characteristics of OAM beams, a new OAM spatial modulation…

Networking and Internet Architecture · Computer Science 2016-12-19 Xiaohu Ge , Ran Zi , Xusheng Xiong , Qiang Li , Liang Wang

The particle definition varies across different theories. The quantum field theory in curved spacetime shows that from the perspective of a linearly accelerated observer, an inertial empty space may be full of thermal particles. This effect…

General Relativity and Quantum Cosmology · Physics 2024-05-08 Haorong Wu , Xilong Fan , Lixiang Chen

Optical vortex beam with orbital angular momentum (OAM) has great potential to increase the capacity of optical communication and information processing in classical and quantum regimes. Nevertheless, important challenges that influence the…

Optics · Physics 2024-03-26 Tong Fu , Gang Luo , Jia Cheng Li , Yuan Chao Geng , Xiao Dong Yuan

This work presents a rigorous statistical and geometric framework for analyzing turbulence-impacted beam propagation and image topology with results obtained using a PMMA slab. The approach models beam intensity distributions as…

Optics · Physics 2025-10-02 Shouvik Sadhukhan , C. S. Narayanamurthy

Orbital angular momentum (OAM)-carrying beams have gained significant attention in recent years due to their unique properties and potential to improve spectral efficiency and data transmission rates in optical communication systems.…

Fast and accurate simulation of imaging through atmospheric turbulence is essential for developing turbulence mitigation algorithms. Recognizing the limitations of previous approaches, we introduce a new concept known as the phase-to-space…

Image and Video Processing · Electrical Eng. & Systems 2021-08-24 Zhiyuan Mao , Nicholas Chimitt , Stanley H. Chan

Recovering images distorted by atmospheric turbulence is a challenging inverse problem due to the stochastic nature of turbulence. Although numerous turbulence mitigation (TM) algorithms have been proposed, their efficiency and…

Image and Video Processing · Electrical Eng. & Systems 2024-04-09 Xingguang Zhang , Nicholas Chimitt , Yiheng Chi , Zhiyuan Mao , Stanley H. Chan

We explore the spatial features of various orders of Fraunhofer diffraction patterns in a four-level N-type atomic system. The system interacts with a weak probe light, a standing wave (SW) coupling field in the x-direction, and a…

Quantum Physics · Physics 2024-01-12 Seyyed Hossein Asadpour , Teodora Kirova , Hamid R. Hamedi , Reza Asgari

Coherent detection can provide enhanced receiver sensitivity and spectral efficiency in free-space optical (FSO) communications. However, turbulence can cause modal power coupling effects on a Gaussian data beam and significantly degrade…