Arbitrary polarization conversion from 0° to 90° based on all-dielectric metasurfaces

Author(s):  
Xiaodong Cai ◽  
Zhiwei Li ◽  
Yongjiu Li ◽  
Kai Wang ◽  
Dunke Lu ◽  
...  
2019 ◽  
Vol 7 (14) ◽  
pp. 1801453 ◽  
Author(s):  
Yu Guo ◽  
Meng Xiao ◽  
Yang Zhou ◽  
Shanhui Fan

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Shuai Wang ◽  
Zi-Lan Deng ◽  
Yujie Wang ◽  
Qingbin Zhou ◽  
Xiaolei Wang ◽  
...  

AbstractThe control of polarization, an essential property of light, is of broad scientific and technological interest. Polarizers are indispensable optical elements for direct polarization generation. However, arbitrary polarization generation, except that of common linear and circular polarization, relies heavily on bulky optical components such as cascading linear polarizers and waveplates. Here, we present an effective strategy for designing all-in-one full Poincaré sphere polarizers based on perfect arbitrary polarization conversion dichroism and implement it in a monolayer all-dielectric metasurface. This strategy allows preferential transmission and conversion of one polarization state located at an arbitrary position on the Poincaré sphere to its handedness-flipped state while completely blocking its orthogonal state. In contrast to previous methods that were limited to only linear or circular polarization, our method manifests perfect dichroism of nearly 100% in theory and greater than 90% experimentally for arbitrary polarization states. By leveraging this attractive dichroism, our demonstration of the generation of polarization beams located at an arbitrary position on a Poincaré sphere directly from unpolarized light can substantially extend the scope of meta-optics and dramatically promote state-of-the-art nanophotonic devices.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thi Kim Thu Nguyen ◽  
Thi Minh Nguyen ◽  
Hong Quang Nguyen ◽  
Thanh Nghia Cao ◽  
Dac Tuyen Le ◽  
...  

AbstractA simple design of a broadband multifunctional polarization converter using an anisotropic metasurface for X-band application is proposed. The proposed polarization converter consists of a periodic array of the two-corner-cut square patch resonators based on the FR-4 substrate that achieves both cross-polarization and linear-to-circular polarization conversions. The simulated results show that the polarization converter displays the linear cross-polarization conversion in the frequency range from 8 to 12 GHz with the polarization conversion efficiency above 90%. The efficiency is kept higher than 80% with wide incident angle up to 45°. Moreover, the proposed design achieves the linear-to-circular polarization conversion at two frequency bands of 7.42–7.6 GHz and 13–13.56 GHz. A prototype of the proposed polarization converter is fabricated and measured, showing a good agreement between the measured and simulated results. The proposed polarization converter exhibits excellent performances such as simple structure, multifunctional property, and large cost-efficient bandwidth and wide incident angle insensitivity in the linear cross polarization conversion, which can be useful for X-band applications. Furthermore, this structure can be extended to design broadband polarization converters in other frequency bands.


Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 586
Author(s):  
Chen-Yi Yu ◽  
Qiu-Chun Zeng ◽  
Chih-Jen Yu ◽  
Chien-Yuan Han ◽  
Chih-Ming Wang

In this study, the phase modulation ability of a dielectric Pancharatnam–Berry (PB) phase metasurface, consisting of nanofins, is theoretically analyzed. It is generally considered that the optical thickness of the unit cell of a PB-phase metasurface is λ/2, i.e., a half-waveplate for polarization conversion. It is found that the λ/2 is not essential for achieving a full 2π modulation. Nevertheless, a λ/2 thickness is still needed for a high polarization conversion efficiency. Moreover, a gradient phase metasurface is designed. With the help of the particle swarm optimization (PSO) method, the wavefront errors of the gradient phase metasurface are reduced by fine-tuning the rotation angle of the nanofins. The diffraction efficiency of the gradient phase metasurface is thus improved from 73.4% to 87.3%. This design rule can be utilized to optimize the efficiency of phase-type meta-devices, such as meta-deflectors and metalenses.


Sign in / Sign up

Export Citation Format

Share Document