Design and demonstration of a wide-angle and high-efficient planar metasurface lens

Liu, Yongqiang; Che, Yongxing; Qi, Kainan; Li, Liangsheng; Yin, Hongcheng

doi:10.1016/j.optcom.2020.126061

Cited by 22 publications

(9 citation statements)

References 19 publications

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“…Wide-angle imaging systems’ richer visual perception has benefited numerous domains, such as autonomous robots, self-driving, and video surveillance [ 8 ]. Although wide-angle imaging systems provide richer information, they always suffer from several problems, especially the transmitted color of light change from different angles.…”

Section: Introductionmentioning

confidence: 99%

Wide-Angular Tolerance Optical Filter Design and Its Application to Green Pepper Segmentation

Shu

Kurihara

2023

Sensors

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The optical filter is critical in many applications requiring wide-angle imaging perception. However, the transmission curve of the typical optical filter will change at an oblique incident angle due to the optical path of the incident light change. In this study, we propose a wide-angular tolerance optical filter design method based on the transfer matrix method and automatic differentiation. A novel optical merit function is proposed for simultaneous optimization at normal and oblique incidents. The simulation results demonstrate that such a wide-angular tolerance design can realize a similar transmittance curve at an oblique incident angle compared to a normal incident angle. Furthermore, how much improvement in a wide-angular optical filter design for oblique incident contributes to image segmentation remains unclear. Therefore, we evaluate several transmittance curves along with the U-Net structure for green pepper segmentation. Although our proposed method is not perfectly equal to the target design, it can achieve an average 50% smaller mean absolute error (MAE) than the original design at 20∘ oblique incident angle. In addition, the green pepper segmentation results show that wide-angular tolerance optical filter design improves the segmentation of the near-color object about 0.3% at 20∘ oblique incident angle compared to the previous design.

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Section: Introductionmentioning

confidence: 99%

Wide-Angular Tolerance Optical Filter Design and Its Application to Green Pepper Segmentation

Shu

Kurihara

2023

Sensors

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“…MMs properties can be utilized in its practical applications from microwave band (MHz) to optical regime (THz), leading toward new theories and corresponding applications. 7 Some of the important applications of MSs include unusual reflection and refraction of light, surface wave conversion, super lensing, invisible cloaks, quarter-and half wave plates, 8 planar lenses, 9 multi spectral photography, 10 and polarization controlling devices. [11][12][13] Metasurfaces can be used as a substrate or superstrate to enhance gain and bandwidth of micro strip patch antennas in microwave regime, such structures are reported in previous works.…”

Section: Introductionmentioning

confidence: 99%

Cross polarization conversion metasurface for fixed wireless and ku‐band applications

Abdullah

Kamal

Ullah

et al. 2021

Int J Communication

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Summary A dual broadband cross‐polarization‐conversion (CPC) metasurface is designed, simulated, fabricated and results are experimentally verified. The designed patch of metasurface unit cell is composed of a triangular loop connected with two arcs at both ends. The metasurface is made of 44 × 44 unit cells arranged periodically on 1.6‐mm‐thick FR4 dielectric substrate, backed by a metallic copper sheet as a reflector surface on the back side of the dielectric substrate. The surface achieves CPC in two bands (7–8.5 GHz) and (13–19 GHz), in the microwave regime. The simulation results show that the polarization conversion ratio (PCR) is almost 90% for both x polarized (TM) and y polarized (TE) electromagnetic (EM) waves. The proposed metasurface is fabricated on 308 × 308 mm2 FR4 substrate plane. The simulated results are validated and are found in close covenant with the measured results.

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“…Although the present metasurfaces can perform a variety of functions, most of the materials used in metasurfaces are copper, aluminum, and other metals, which are optically opaque. − However, the opacity limits the application of metasurfaces in areas requiring transparency, such as optical windows. The transparent metasurfaces are essential for the display screens of communication devices, the cockpit covers of aircraft, and the detection windows of satellites.…”

Section: Introductionmentioning

confidence: 99%

Visible-Infrared Transparent Coding Metasurface Based on Random Metal Grid for Broadband Microwave Scattering

Zhong¹,

Liu

Yang

et al. 2021

ACS Appl. Electron. Mater.

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The broad applications of manipulation of electromagnetic waves (EMWs) in imaging, detection, communication, and electronic countermeasures have drawn extensive attention to the metasurface. In these applications, maintaining transparency to visible light is challenging, especially when high transmittance in the infrared band is also required, not to mention when the substrate is a nondevelopable surface. Although ITO-based metasurfaces can transmit visible light, ITO cannot transmit infrared and has poor mechanical properties, coupled with shortcomings such as the scarcity of indium, which together limit their application. Here, the random metal grid and coding metasurface are first integrated, which achieves a random metal grid-based coding metasurface (RMGCM), for flexible microwave manipulation while maintaining high transmittance from visible to infrared. As a proof of principle, a polarization-insensitive, broadband range (19–23 GHz) RMGCM that can scatter microwaves over a wide angle range of 0 to 45° is obtained. The uniformity of the stray light of the random metal grid and the good substrate compatibility of its fabrication technique, coupled with the powerful ability of the metasurface provide RMGCM with broad application prospects. One of the potential applications is the cockpit of a stealth aircraft that requires virtual shaping. In addition, combined with flexible substrates and random metal grids with smaller periods, this structure can be further improved to extend to wearable devices and terahertz fields.

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Design and demonstration of a wide-angle and high-efficient planar metasurface lens

Cited by 22 publications

References 19 publications

Wide-Angular Tolerance Optical Filter Design and Its Application to Green Pepper Segmentation

Wide-Angular Tolerance Optical Filter Design and Its Application to Green Pepper Segmentation

Cross polarization conversion metasurface for fixed wireless and ku‐band applications

Visible-Infrared Transparent Coding Metasurface Based on Random Metal Grid for Broadband Microwave Scattering

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