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Because of their exceptional capability to tailor the effective medium parameters, metamaterials have been widely used to control electromagnetic waves, which has led to the observation of many interesting phenomena, for example, negative refraction, invisibility cloaking, and anomalous reflections and transmissions. However, the studies of metamaterials or metasurfaces are mainly limited to their physical features; currently, there is a lack of viewpoints on metamaterials and metasurfaces from the information perspective. Here we propose to measure the information of a coding metasurface using Shannon entropy. We establish an analytical connection between the coding pattern of an arbitrary coding metasurface and its far-field pattern. We introduce geometrical entropy to describe the information of the coding pattern (or coding sequence) and physical entropy to describe the information of the far-field pattern of the metasurface. The coding metasurface is demonstrated to enhance the information in transmitting messages, and the amount of enhanced information can be manipulated by designing the coding pattern with different information entropies. The proposed concepts and entropy control method will be helpful in new information systems (for example, communication, radar and imaging) that are based on the coding metasurfaces.
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http://dx.doi.org/10.1038/lsa.2016.172 | DOI Listing |
Nat Commun
September 2025
State Key Laboratory of Precision Measurement Technology and Instruments, Tianjin University, Tianjin, China.
Phased arrays are crucial in various technologies, such as radar and wireless communications, due to their ability to precisely control and steer electromagnetic waves. This precise control improves signal processing and enhances imaging performance. However, extending phased arrays to the terahertz (THz) frequency range has proven challenging, especially for high-frequency operation, broadband performance, two-dimensional (2D) phase control with large antenna arrays, and flexible phase modulation.
View Article and Find Full Text PDFNat Commun
August 2025
State Key Laboratory of Millimeter Waves and Institute of Electromagnetic Space, Southeast University, Nanjing, China.
Brain-computer interface (BCI) provides an interconnected pathway between the human brain and external devices and paves a potential route for mind manipulations. However, most existing BCI technologies are based on simple signal transmission and are independent of other interface devices, with limited consideration for the reliability and security of the human brain's information interaction in complicated wireless environments. Here, we propose a deep fusion coding scheme that combines the BCI visual stimulation coding with metasurface space-time coding at the physical layer, enabling reliable and secure information transfers between the human brain and external devices.
View Article and Find Full Text PDFIn this Letter, a transmission-reflection integrated programmable metasurface, which achieves quasi-360° phase coverage in the reflection mode and 1-bit phase coding in the transmission mode, is proposed. The steering manipulation of the zeroth-order Bessel beam is investigated over an angular range of 10°-30° in the reflection space, verifying the reconfigurability of the proposed metasurface. Correspondingly, in the transmission space, beam steering is achieved from -10° to -30°, thereby showcasing full-space scanning capabilities.
View Article and Find Full Text PDFNatl Sci Rev
September 2025
School of Electronic Engineering, Xidian University, Xi'an 710071, China.
The increasing demand for public safety has created an urgent need for high-performance technologies capable of detecting hazardous liquids with high accuracy, efficiency, and cost-effectiveness. Conventional liquid detection methods often fall short in addressing these requirements due to limitations in precision, operational complexity, and scalability. This study introduces a wireless intelligent system for the detection of suspicious liquids, leveraging advancements in programmable metasurface and software defined radio technologies.
View Article and Find Full Text PDFOpt Express
February 2025
Vortex beams carrying orbital angular momentum (OAM) exhibit excellent potential for applications in fields such as sixth-generation communication, quantum information processing, and imaging technologies. However, the realization of multi-mode and full-space continuous precision modulation of vortex beams still faces significant challenges. In this study, a terahertz full-space coding metasurface based on vanadium dioxide (VO) is proposed, combined with a more accurate generalized coding strategy, convolution, and generalized superposition methods to achieve continuous and precise modulation of vortex beams.
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