Abstract-Highly efficient beam control of transmitted terahertz wave based on all dielectric encoding metasurface

Bo Fang, Zhigang Yan, Jing Fan,  Cenke Qi, Haiyong Gan, Yingwei He, Chenxia Li, Zhi Hong, Xufeng Jing,

https://www.sciencedirect.com/science/article/abs/pii/S0030401819309083

To overcome the intrinsic nonradiative losses in metallic encoding metasurface, we propose an all dielectric encoding metasurface by using cylinder microstructure. To flexibly manipulate the transmitted terahertz wave with various scattering angles, 1bit and 2bit encoding metasurfaces in x-direction coding, y-direction coding, and the chessboard coding are established. According to the scattering theory of traditional phase array antennas, the far field scattering of coding metasurface at normal incidence is deduced for 1bit coding mode. It should be noted that the scattering principle of beam control can be also applied in multiple bits encoding metasurface. This work opens up a digital perspective for encoding methods with high efficiency, making it possible to combine electromagnetic wave manipulation with digital signal processing.

Abstract-Improvement of Wide-Angle Response for Terahertz Carpet Cloaking by Using a Metasurface with Multilayer Microstructure

Meng Li, Shuang Han, Haiyong Gan, Chenxia Li, Jianjun Liu, Zhi Hong, Xufeng Jing, 

https://link.springer.com/article/10.1007%2Fs10762-019-00617-w

A metasurface provides a completely new path to realize a cloaking effect by using phase compensation. However, the traditional invisible cloaks by using metasurfaces are limited at the narrow bandwidth and angle response. Here, we propose a multilayer metasurface to construct a cloak device, and more geometric freedom ensures the broadband and wide-angle response of our designed cloak. The invisible effect is revealed by near-field and far-field distribution for the ground plane, bare bump, and cloak, respectively. Our designed cloaking with the metasurface composed of five-layer unit cell structure has a good invisible effect at the broadband range from 0.7 to 0.8 THz and has a wide-angle response from 35 to 50°.

Abstract-Guided mode resonance in terahertz compound metamaterial waveguides

Jianjun Liu, Hang Chen, Xufeng Jing, Zhi Hong


https://www.sciencedirect.com/science/article/pii/S0030402618311148

Guided mode resonances (GMR) in a planar compound metamaterial (MM) consisting of two square closed ring resonators were numerically calculated and experimentally demonstrated. The strength and bandwidth of the GMR can be controlled by changing the distance between the two square rings. Moreover, asymmetric Fano resonance or electromagnetic induced transparency (EIT) was realized by manipulating the interaction between the GMR and the dipolar resonance of the MM. The measured results at terahertz frequencies are in good agreement with simulations

Abstract-Broadband polarization-independent two-dimensionally isotropic ultrahigh index metamaterials

Xincui Gui, Xufeng Jing, Jianjun Liu, Pengwei Zhou, Zhi Hong,

https://www.sciencedirect.com/science/article/pii/S1350449517305637

By drastically decreasing the diamagnetic effect with a thin window type structure in the unit cell and increasing the effective permittivity through strong capacitive coupling, we report a window-type broadband isotropic two-dimensional metamaterial with extremely high refractive index in the terahertz region. The designed peak index of refraction of near 18.22 at about 1.15 THz is predicted. In the experiment, we fabricated a “window” type structural metamaterial, and the measured transmission was compared with the results of the simulation. The effective refractive index for the prepared metamaterial was extracted by S-parameter extraction method. It is found that ultrahigh refractive index metamaterials depend on the electric field coupling effect, the magnetic field diamagnetic response, and the geometric parameters in the unit cell. Higher resonant frequency makes it possible to utilize broader high refractive index with low loss and large transmission.

Abstract-Design of ultrahigh refractive index metamaterials in the terahertz regime

• Xufeng Jing^1,  
• Rui Xia¹, 
• Xincui Gui¹, 
• Weimin Wang¹, 
• Ying Tian², 
• Dongshuo Zhu³, 
• Guohua Shi⁴

• ¹ Institute of Optoelectronic Technology, China Jiliang University, Hangzhou 310018, China
• ² College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018, China
• ³ Institute of art and design, Renmin university of China
• ⁴ Jiangsu Key Laboratory of Medical Optics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China

http://www.sciencedirect.com/science/article/pii/S0749603617306237

A high refractive index metamaterial was theoretically designed in the terahertz region, and the proposed structure is to easy implementation. By decreasing the diamagnetic effect with a thin “I”-shaped metallic patch structure and drastically increasing the effective permittivity through strong capacitive coupling in the unit cell, the higher refractive index of designed metamaterial can be obtained while maintaining low losses in the resonant frequency. The physical mechanism of metamaterial possessing an enhanced refractive index is revealed by the surface current, the electric field and magnetic field distributions. Besides, the polarization characteristics and broad incident angles robustness for the high refractive index are demonstrated.

Abstract-Manipulation of dual band ultrahigh index metamaterials in the terahertz region

Xufeng Jing, Weimin Wang, Rui Xia, Jingyin Zhao, Ying Tian, and Zhi Hong

https://www.osapublishing.org/ao/abstract.cfm?URI=ao-55-31-8743

By drastically decreasing the diamagnetic effect with a thin metallic structure in the unit cell and increasing the effective permittivity through strong capacitive coupling, we designed the crossed I-shaped metallic patches metamaterial with an extremely high refractive index in the dual band terahertz region. The peak index of refraction of near 80 at about 0.75 THz is predicted, along with another peak index of about 25 at 2.85 THz. Based on the careful analysis of the high index on the dependence of the electric field coupling effect, the magnetic field diamagnetic response, and the geometric parameters in the unit cell, it is found that both of the high index bands respectively correspond to different components in the metamaterial structure. To realize a higher effective refractive index for the second band as well as for the first one, we proposed the triple I-shaped metallic metamaterial structure.

© 2016 Optical Society of America

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Abstract-Manipulation of dual band ultrahigh index metamaterials in the terahertz region

Xufeng Jing, Weimin Wang, Rui Xia, Jingyin Zhao, Ying Tian, and Zhi Hong

https://www.osapublishing.org/ao/abstract.cfm?uri=ao-55-31-8743

By drastically decreasing the diamagnetic effect with a thin metallic structure in the unit cell and increasing the effective permittivity through strong capacitive coupling, we designed the crossed I-shaped metallic patches metamaterial with an extremely high refractive index in the dual band terahertz region. The peak index of refraction of near 80 at about 0.75 THz is predicted, along with another peak index of about 25 at 2.85 THz. Based on the careful analysis of the high index on the dependence of the electric field coupling effect, the magnetic field diamagnetic response, and the geometric parameters in the unit cell, it is found that both of the high index bands respectively correspond to different components in the metamaterial structure. To realize a higher effective refractive index for the second band as well as for the first one, we proposed the triple I-shaped metallic metamaterial structure.

© 2016 Optical Society of America

Full Article  |  PDF Article