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A 1-bit electronically reconfigurable beam steerable metasurface reflectarray with multiple polarization manipulations

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Chinese Physics B 2024年第1期33卷 384-394页

作者：史琰徐茜雅王少泽魏文岳武全伟 School of Electronic Engineering Xidian UniversityXi'an 710071China

A 1-bit electronically controlled metasurface reflectarray is presented to achieve beam steering with multiple polarization manipulations. A metsurface unit cell loaded by two PIN diodes is designed. By switching the two PIN diodes between ON and OFF states, the isotropic and anisotropic reflections can be flexibly achieved. For either the isotropic reflection or the anisotropic reflection, the two operation states achieve the reflection coefficients with approximately equal magnitude and 180°out of phase, thus giving rise to the isotropic/anisotropic 1-bit metasurface unit cells. With the 1-bit unit cells, a 12-by-12 metasurface reflectarray is optimally designed and fabricated. Under either y-or x-polarized incident wave illumination, the reflectarray can achieve the co-polarized and cross-polarized beam scanning, respectively, with the peak gains of 20.08 d Bi and 17.26 d Bi within the scan range of about ±50°. With the right-handed circular polarization(RHCP) excitation, the left-handed circular polarization(LHCP) radiation with the peak gain of 16.98 d Bic can be achieved within the scan range of ±50°. Good agreement between the experimental results and the simulation results are observed for 2D beam steering and polarization manipulation capabilities.

关键词： electronically controlled metasurface reflectarray beam steering polarization manipulation

polarization-switchable plasmonic emitters based on laser-induced bubbles

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Opto-Electronic Advances 2022年第8期5卷 11-20页

作者： Jianjun Chen Fengyuan Gan Department of Physics and Applied Optics Beijing Area Major Laboratory Beijing Normal UniversityBeijing 100875China State Key Laboratory for Mesoscopic Physics School of PhysicsPeking UniversityBeijing 100871China Peking University Yangtze Delta Institute of Optoelectronics Nantong 226010China Frontiers Science Center for Nano-optoelectronics&Collaborative Innovation Center of Quantum Matter Peking UniversityBeijing 100871China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

Owing to weak light-matter interactions in natural materials,it is difficult to dynamically tune and switch emission polariza-tion states of plasmonic emitters(or antennas)at nanometer ***,by using a control laser beam to induce a bubble(n=1.0)in water(n=1.333)to obtain a large index variation as high as|Δn|=0.333,the emission polarization of an ultra-small plasmonic emitter(~0.4λ^(2))is experimentally switched at nanometer *** plasmonic emitter consists of two orthogonal subwavelength metallic nanogroove antennas on a metal surface,and the separation of the two anten-nas is only s_(x)=120 *** emission polarization state of the plasmonic emitter is related to the phase difference between the emission light from the two *** of a large refractive index variation(|Δn|=0.333),the phase difference is greatly changed when a microbubble emerges in water under a low-intensity control *** a result,the emission polarization of the ultra-small plasmonic emitter is dynamically switched from an elliptical polarization state to a linear polarization state,and the change of the degree of linear polarization is as high asΔγ≈0.66.

关键词： plasmonic emitters nanometer scales polarization manipulation dynamical switching bubbles

Spintronic terahertz emission with manipulated polarization (STEMP)

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Frontiers of Optoelectronics 2022年第1期15卷 128-142页

作者： Peiyan Li Shaojie Liu Xinhou Chen Chunyan Geng Xiaojun Wu School of Electronic and Information Engineering Beihang UniversityBeijing 100191China School of Cyber Science and Technology Beihang UniversityBeijing 100191China Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China

Highly efficient generation and arbitrary manipulation of spin-polarized terahertz(THz)radiation will enable chiral lightwave driven quantum nonequilibrium state regulation,induce new electronic structures,consequently provide a powerful experi-mental tool for investigation of nonlinear THz optics and extreme THz science and *** circular dichromic spectroscopy,ultrafast electron bunch manipulation,as well as THz imaging,sensing,and telecommunication,also need chiral THz *** we review optical generation of circularly-polarized THz radiation but focus on recently emerged polarization tunable spintronic THz emission techniques,which possess many advantages of ultra-broadband,high efficiency,low cost,easy for integration and so *** believe that chiral THz sources based on the combination of electron spin,ultra-fast optical techniques and material structure engineering will accelerate the development of THz science and applications.

关键词： Terahertz(THz)emission Femtosecond laser Spintronics polarization manipulation

High-resolution grayscale image hidden in a laser beam

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Light(Science & Applications) 2017年第1期6卷 243-248页

作者： Fuyong Yue Chunmei Zhang Xiao-Fei Zang Dandan Wen Brian D Gerardot Shuang Zhang Xianzhong Chen SUPA Institute of Photonics and Quantum SciencesSchool of Engineering and Physical SciencesHeriot-Watt UniversityEdinburgh EH144ASUK Shanghai Key Lab of Modern Optical System University of Shanghai for Science and TechnologyShanghai 200093China School of Physics and Astronomy University of BirminghamBirmingham B152TTUK

Images perceived by human eyes or recorded by cameras are usually optical patterns with spatially varying intensity or color *** addition to the intensity and color,the information of an image can be encoded in a spatially varying distribution of phase or polarization ***,such images might not be able to be directly viewed by human eyes or cameras because they may exhibit highly uniform intensity ***,we propose and experimentally demonstrate an approach to hide a high-resolution grayscale image in a square laser beam with a size of less than half a *** image with a pixel size of 300×300 nm is encoded into the spatially variant polarization states of the laser beam,which can be revealed after passing through a linear *** unique technology for hiding grayscale images and polarization manipulation provides new opportunities for various applications,including encryption,imaging,optical communications,quantum science and fundamental physics.

关键词： grayscale image metasurface polarization manipulation