scholarly journals High-Efficiency, Dual-Band Beam Splitter Based on an All-Dielectric Quasi-Continuous Metasurface

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3184
Author(s):  
Jing Li ◽  
Yonggang He ◽  
Han Ye ◽  
Tiesheng Wu ◽  
Yumin Liu ◽  
...  

Metasurface-based beam splitters attracted huge interest for their superior properties compared with conventional ones made of bulk materials. The previously reported designs adopted discrete metasurfaces with the limitation of a discontinuous phase profile. In this paper, we propose a dual-band beam splitter, based on an anisotropic quasi-continuous metasurface, by exploring the optical responses under x-polarized (with an electric field parallel to the direction of the phase gradient) and y-polarized incidences. The adopted metasurface consists of two identical trapezoidal silicon antenna arrays with opposite spatial variations that lead to opposite phase gradients. The operational window of the proposed beam splitter falls in the infrared and visible region, respectively, for x- and y-polarized light, resulting from the different mechanisms. When x-polarized light is incident, the conversion efficiency and total transmission of the beam splitter remains higher than 90% and 0.74 within the wavelength range from 969 nm to 1054 nm, respectively. In this condition, each array can act as a beam splitter of unequal power. For y-polarized incidence, the maximum conversion efficiency and transmission reach approximately 100% and 0.85, while the values remain higher than 90% and 0.65 in the wavelength range from 687 nm to 710 nm, respectively. In this case, each array can be viewed as an effective beam deflector. We anticipate that it can play a key role in future integrated optical devices.

2018 ◽  
Vol 6 (6) ◽  
pp. 517 ◽  
Author(s):  
Liu Yang ◽  
Dong Wu ◽  
Yumin Liu ◽  
Chang Liu ◽  
Zenghui Xu ◽  
...  

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Siyuan Shen ◽  
Zhaohui Ruan ◽  
Yuan Yuan ◽  
Heping Tan

Abstract The generalized Snell’s law dictates that introducing a phase gradient at the interface of two media can shape incident light and achieve anomalous reflection or refraction. However, when the introduced phase gradient is realized via the scattering of nanoparticles in the metasurfaces, this law needs to be modified; certain conditions need to be met when the law is established. We present the conditions for establishing the “generalized Snell’s law of refraction” in all-dielectric metasurfaces under the incidence of different polarized light. These conditions can provide theoretical bases for the subsequent design of high-efficiency beam deflection metasurfaces. The relationship between the highest achievable anomalous refraction efficiency and the number of nanoparticles within one period of the metasurface is also summarized. In addition, the generalized refraction should not depend on the polarization states of incident light; however, the previous realization conditions of anomalous refraction were sensitive to the polarization states. Thus, conditions for establishing the polarization-independent generalized Snell’s law of refraction in all-dielectric metasurfaces are presented.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5967
Author(s):  
Tiesheng Wu ◽  
Zhihui Liu ◽  
Weiping Cao ◽  
Huixian Zhang ◽  
Dan Yang ◽  
...  

All-dielectric Huygens’ metasurfaces have been widely used in wavefront manipulation through multipole interactions. Huygens’ metasurfaces utilize the superposition between an electric dipole and a magnetic dipole resonance to realize transmission enhancement and an accumulated 2π phase change. Benefiting from this unique property, we design and numerically investigate an all-dielectric Huygens’ metasurface exhibiting high-efficiency anomalous refraction. To suppress the substrate effect, the metasurface structure is submerged in a dielectric plate. We strategically placed two elements in four short periods to form a unit cell and adjusted the spacing between the two elements to effectively inhibit the interaction between elements. At the operating wavelength of 692 nm, the obtained anomalous transmission efficiency is over 90.7% with a diffraction angle of 30.84°. The performance of the proposed structure is far superior to most of the existing phase-gradient metasurface structures in the visible region, which paves the way for designing efficient beam deflection devices.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Tiesheng Wu ◽  
Zhihui Liu ◽  
Yiping Wang ◽  
Huixian Zhang ◽  
Zuning Yang ◽  
...  

AbstractWe propose and numerically demonstrate a phase-gradient metasurface with high anomalous transmission efficiency and a large anomalous refraction angle that consists of discontinuous regular hexagonal nanorods supported by a silica substrate. The metasurface achieves high anomalous transmission efficiency and a full 2$$\pi$$ π phase shift for the wavelength range of 1400–1600 nm. At a central wavelength of approximately 1529 nm, the total transmission efficiency reaches 96.5%, and the desired anomalous transmission efficiency reaches 96.2%, with an anomalous refraction angle as large as 30.64. With the adjustment of the period and the number of nanorods per periodic interval, the anomalous transmission efficiency exceeds 69.6% for a large anomalous refraction angle of 68.58. The superior performance of the proposed design may pave the way for its application in optical wavefront control devices.


Nanophotonics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 3357-3365 ◽  
Author(s):  
Shaohua Dong ◽  
Qing Zhang ◽  
Guangtao Cao ◽  
Jincheng Ni ◽  
Ting Shi ◽  
...  

AbstractPlasmons, as emerging optical diffraction-unlimited information carriers, promise the high-capacity, high-speed, and integrated photonic chips. The on-chip precise manipulations of plasmon in an arbitrary platform, whether two-dimensional (2D) or one-dimensional (1D), appears demanding but non-trivial. Here, we proposed a meta-wall, consisting of specifically designed meta-atoms, that allows the high-efficiency transformation of propagating plasmon polaritons from 2D platforms to 1D plasmonic waveguides, forming the trans-dimensional plasmonic routers. The mechanism to compensate the momentum transformation in the router can be traced via a local dynamic phase gradient of the meta-atom and reciprocal lattice vector. To demonstrate such a scheme, a directional router based on phase-gradient meta-wall is designed to couple 2D SPP to a 1D plasmonic waveguide, while a unidirectional router based on grating metawall is designed to route 2D SPP to the arbitrarily desired direction along the 1D plasmonic waveguide by changing the incident angle of 2D SPP. The on-chip routers of trans-dimensional SPP demonstrated here provide a flexible tool to manipulate propagation of surface plasmon polaritons (SPPs) and may pave the way for designing integrated plasmonic network and devices.


Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 198
Author(s):  
Geyu Tang ◽  
Huamao Huang ◽  
Yuqi Liu ◽  
Hong Wang

We propose a new compact polarization beam splitter based on the self-collimation effect of two-dimensional photonic crystals and photonic bandgap characteristics. The device is composed of a rectangular air holes-based polarization beam splitting structure and circular air holes-based self-collimating structure. By inserting the polarization beam splitting structure into the self-collimating structure, the TE and TM polarized lights are orthogonally separated at their junction. When the number of rows in the hypotenuse of the inserted rectangular holes is 5, the transmittance of TE polarized light at 1550 nm is 95.4% and the corresponding polarization extinction ratio is 23 dB; on the other hand, the transmittance of TM polarized light is 88.5% and the corresponding polarization extinction ratio is 37 dB. For TE and TM polarized lights covering a 100 nm bandwidth, the TE and TM polarization extinction ratios are higher than 18 dB and 30 dB, respectively. Compared with the previous polarization beam splitters, our structure is simple, the size is small, and the extinction ratio is high, which meets the needs of modern optical communications, optical interconnection, and optical integrated systems.


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