Results 51 to 60 of about 5,982 (227)

Non‐Uniform Space‐Time‐Coding Modulation for Low‐Complexity Diagnostics of Reconfigurable Intelligent Surfaces

Advanced Electronic Materials, EarlyView.
A diagnostic method for reconfigurable intelligent surfaces (RIS) based on non‐uniform space‐time‐coding modulation is presented. Fault localization is achieved via amplitude‐only spectral measurements, eliminating the need for complex signal processing. A one‐to‐one mapping between harmonic components and RIS elements enables accurate detection.
Xiao Qing Chen, Lei Zhang, Yi Ning Zheng, Bing Bing Zhu, Marco Rossi, Giuseppe Castaldi, Shuo Liu, Vincenzo Galdi, Tie Jun Cui   +8 more
wiley   +1 more source

Spherical aberration correction suitable for a wavefront controller

Optics Express, 2009
We propose a simple method to correct a large amount of spherical aberration caused by a refractive index mismatch. The method is based on inverse ray tracing and can generate correction phase patterns whose peak-to-valley values are minimized. We also demonstrated spherical aberration correction in a transparent acrylic block using a liquid-crystal-on-
Haruyasu, Itoh, Naoya, Matsumoto, Takashi, Inoue   +2 more
openaire   +2 more sources

Terahertz Channel Modeling, Estimation and Localization in RIS‐Assisted Systems

Advanced Electronic Materials, EarlyView.
Reconfigurable intelligent surfaces have become a recent intensive research focus. Based on practical applications, channel strategies for RIS‐assisted terahertz wireless communication systems are categorized into three different types: channel modeling, channel estimation, and channel localization.
Hongjing Wang, Weipeng Wang, Xuan Cong, Shiyu Wang, Gao Li, Sen Gong, Lin Huang, Hongxin Zeng, Yaxin Zhang, Ziqiang Yang   +9 more
wiley   +1 more source

Deep Learning Correction Algorithm for The Active Optics System

Sensors, 2020
The correction of wavefront aberration plays a vital role in active optics. The traditional correction algorithms based on the deformation of the mirror cannot effectively deal with disturbances in the real system.
Wenxiang Li, Chao Kang, Hengrui Guan, Shen Huang, Jinbiao Zhao, Xiaojun Zhou, Jinpeng Li   +6 more
doaj   +1 more source

Limitations of the ocular wavefront correction with contact lenses

Vision Research, 2009
We analyze theoretically, by means of both computer simulations and laboratory experiments, the limitations of correcting aberrations with ideal customized contact lenses. Four experiments are presented: In the first one, we have analyzed the limitations of a static correction on the dynamic wavefront.
López-Gil, Norberto, Castejón-Mochón, José Francisco, Fernández-Sánchez, Vicente   +2 more
openaire   +2 more sources

Overcoming the Phase Discontinuity Problem in RIS Optimization: A Robust and Scalable Phase‐Aware Deep Regression Framework via Hybrid CNN–LSTM Architecture

Advanced Intelligent Systems, EarlyView.
The phase discontinuity problem—where the cyclic nature of phase angles causes catastrophic errors near the ±π boundary—is a fundamental obstacle in learning‐based reconfigurable intelligent surface (RIS) optimization. A phase‐aware hybrid CNN–LSTM framework resolves this by decomposing phase predictions into sine–cosine components, mapping circular ...
Seda Savaşçı Şen, Ali Çalhan, Murtaza Cicioğlu, Oğuzhan Demiryürek   +3 more
wiley   +1 more source

Research Progress in Information Processing Methods for Computational Optical Systems

Shuju Caiji Yu Chuli
Aberration is a crucial factor that restricts the imaging performance of optical systems， leading to degraded imaging effects such as blurred details and reduced resolution.
SHAO Xiaopeng, DENG Yishuang, CHEN Yutong, ZHANG Yinuo, WANG Huihui, WU Tengfei, WEI Shijie   +6 more
doaj   +1 more source

The ORCA‐TWIN qCMOS Experiment I. Science Case and Commissioning at Calar Alto Observatory

Astronomische Nachrichten, EarlyView.
ABSTRACT We describe a pilot study to explore a new generation of fast and low noise CMOS image sensors for time domain astronomy, using two remote telescopes with a baseline of 1635 km. The experiment involves direct imaging with novel qCMOS image sensor technology that combines fast readout with sub‐electron readout noise.
Martin M. Roth, Paško Roje, Stella Vješnica, Stefan Cikota, Alex J. Brown, Mike Kretlow, Marco Azzaro, Santiago Reinhart, Jesús Aceituno, Harry Dawson, Carsten Denker, Torsten Enßlin, Stephan Geier, Thomas Granzer, Thomas Kupfer, Gianluca Li Causi, Samaya Nissanke, José Luis Ortiz, Fernando Pedichini, Katja Poppenhäger, Axel Schwope   +20 more
wiley   +1 more source

HotLoop optimization of petawatt laser focal spot via a twin-focus scheme [PDF]

Matter and Radiation at Extremes
Achieving diffraction-limited focusing of high-power laser pulses to generate ultrahigh intensities is crucial for developing compact laser-driven particle accelerators and exploring strong-field quantum electrodynamics.
Qingfan Wu, Ying Gao, Minjian Wu, Jiarui Zhao, Shiyou Chen, Tianhao Liang, Haoran Chen, Tan Song, Zhongshuai Zhang, Zhangyi Wu, Shirui Xu, Ziyang Peng, Tianqi Xu, Zhuo Pan, Yujia Zhang, Qihang Han, Ke Chen, Chenghao Hua, Pengcheng Fan, Yuntian Xie, Yifei Shen, Shengxuan Xu, Liyong Ma, Yixing Geng, Chen Lin, Yanying Zhao, Xueqing Yan, Wenjun Ma   +27 more
doaj   +1 more source

Stochastic Optimization for Adaptive Real-Time Wavefront Correction

Numerical Algorithms, 2003
We have investigated the performance of an adaptive optics system subjected to changing atmospheric conditions, under the guidance of the ALOPEX stochastic optimization. Atmospheric distortions are smoothed out by means of a deformable mirror, the shape of which can be altered in order to follow the rapidly changing atmospheric phase fluctuations. In a
M. S. Zakynthinaki, Yiannis G. Saridakis
openaire   +3 more sources