Article
Optics
Zhengli Han, Yuma Takida, Seigo Ohno, Hiroaki Minamide
Summary: This article presents a metamaterial-based thin-film lens that can focus light at the terahertz frequency with high transmittance, short focal length, and subwavelength thickness. By alternating concentric metamaterial-patterned and un-patterned zones, the lens achieves a diffraction-limited resolution of 0.6 mm for imaging applications.
Article
Multidisciplinary Sciences
Shihab Al-Daffaie, Alaa Jabbar Jumaah, Veronica Lain Rubio, Thomas Kusserow
Summary: An integrated lens-antenna is developed for a nanocontact based terahertz (THz) photomixer, providing a compact alternative to the bulky silicon lens. By using the Fresnel Zone Plate and simulating with the Meep tool, the lens-antenna is successfully integrated with the THz nanophotomixer. Experimental results demonstrate that the compact design of the lens-antenna exhibits comparable performance to the conventional bulky silicon lens, making it suitable for photonic integrated circuits based THz systems.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Multidisciplinary
Shaobo Ge, Weiguo Liu, Xueping Sun, Jin Zhang, Pengfei Yang, Yingxue Xi, Shun Zhou, Yechuan Zhu, Xinxin Pu
Summary: This paper creatively utilizes the diffraction theory and electromagnetic resonance effect to design a multifunctional metasurface zone plate (MMZP) for controlling polarization states and achieving broadband achromatic converging property. The MMZP consists of rings with fixed width and varying heights, each containing nanofins (meta-atoms). Numerical simulation reveals that the MMZP can manipulate polarization while maintaining broadband focusing, achieving an efficiency above 35% at a specific wavelength and independence with the polarization state of incident light. This approach expands the freedom in micro-nano optical design and is expected to be applied in multifunctional focusing devices and polarization imaging.
Article
Optics
Junbo Hao, Jie Lin, Xin Ye, Chen Chen, Feng Tang, Zhongliang Li, Chang Li, Jianyang Hu, Peng Jin
Summary: This article proposes a polarization-optimized subwavelength metasurface Fresnel zone plate (POMFZP) to achieve extended depth of focus (DOF) and multiple focal spots. The incident linearly polarized beam is converted to a beam with optimized polarization distribution to approximate the predefined on-axis intensity distribution. The focusing characteristics of two designed POMFZPs are numerically demonstrated.
OPTICS COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Xiaoqiang Zhang, Yong Xu, Bin Hong, Fan Zhang, Anting Wang, Weisheng Zhao
Summary: In this paper, a spintronic terahertz emitter with a helical Fresnel zone plate is designed to generate focused terahertz vortex beams with topological charges. The focused electric field with orbital angular momentum has potential applications in THz communications, imaging, and atom trapping.
Article
Engineering, Electrical & Electronic
Chao Ma, Huan Li, Bin Zhang, Dexin Ye, Jiangtao Huangfu, Yongzhi Sun, Weiqiang Zhu, Changzhi Li, Lixin Ran
Summary: A 2-D beam-steering FZP antenna with only 180 degrees phase tunability is reported, combining the advantages of active FSS and conventional 1-D FZP antennas. The antenna works within an ultrawide bandwidth with a gain up to 19.3 dBi and a scanning range of +/- 45 degrees, showing potential for diverse RF and microwave applications.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Optics
Xiaolong You, Rajour T. Ako, Wendy S. L. Lee, Madhu Bhaskaran, Sharath Sriram, Christophe Fumeaux, Withawat Withayachumnankul
Summary: Polarization conversion is widely used in biology, chemistry, and communications. To enhance efficiency and bandwidth, a transmissive half-wave plate is designed based on the concept of Huygens' metasurface, achieving a wider frequency range and higher efficiency.
Article
Nanoscience & Nanotechnology
Zhipeng Wang, Lan Jiang, Xiaowei Li, Shuai Gao, Shipeng Zhou, Yang Liu, Lingling Huang, Jiangang Lu, Jiangang Yin
Summary: This paper discusses a high efficiency method for fabricating ultrathin FZPs of different scales on metal films using holographic femtosecond lasers. The study demonstrates the capability of cross-scale fabrication and presents the excellent imaging ability of the fabricated FZPs in the visible spectrum.
Article
Engineering, Electrical & Electronic
Jianfeng Zhu, Yang Yang, Zhangju Hou, Shaowei Liao, Quan Xue
Summary: This paper presents a dual-band aperture-shared high gain antenna for millimeter-wave (mm-wave) and sub-6 GHz applications. By integrating a transmitarray into a Fresnel zone plate lens, high gain radiation is achieved in both frequency bands.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Nanoscience & Nanotechnology
Hyunwoo Park, Sodam Jeong, Changwon Seo, Hyeongi Park, Donghak Oh, Jae-Eon Shim, Jaeyeong Lee, Taewoo Ha, Hyeon-Don Kim, Soojeong Baek, Bumki Min, Teun-Teun Kim
Summary: In this study, the researchers demonstrate that the phase retardation of a THz wave can be electrically controlled by integrating patterned mono- and bilayer graphene onto an isotropic metasurface. By modulating the conductivity of graphene, the refractive index for one of the polarization states can be controlled, allowing for the manipulation of electromagnetic wave polarization states. This work opens up opportunities for the development of compact THz polarization devices and polarization-sensitive THz technology.
Article
Optics
Jie Li, Xiao Liu, Yuting Wang, Hang Xu, Hui Li, Zhen Yue, Yue Yang, Yu He, Xiao Liang, Li Luo, Tingting Tang, Jianquan Yao
Summary: This letter proposes a new method for circularly polarized wave manipulation based on a zone plate. By using chirality meta-atoms and binary geometric phase, the simultaneous focusing of reflected and transmitted terahertz waves is achieved. The silicon-based dielectric chiral units separate the orthogonal circularly polarized components, and a binary Pancharatnam-Berry phase gradient is obtained for easy design of the phase zone plate. Simulation results show that the proposed chiral metasurface zone plate has the function of reflection-transmission separation and focusing for the circularly polarized terahertz waves.
Article
Chemistry, Multidisciplinary
Zhen Yue, Chenglong Zheng, Jie Li, Jitao Li, Jingyu Liu, Guocui Wang, Mingyang Chen, Hang Xu, Qi Tan, Haijian Zhang, Yating Zhang, Yan Zhang, Jianquan Yao
Summary: Chiral metasurfaces can achieve different optical responses for left-handed and right-handed circularly polarized light, and can realize spin-selective transmission in a dual band.
Article
Engineering, Electrical & Electronic
Mikko Kokkonen, Petra S. Palvolgyi, Rafal Sliz, Heli Jantunen, Krisztian Kordas, Sami Myllymaki
Summary: In this study, a 300 GHz Fresnel zone plate lens supported by an ultraporous silica foam substrate with a nanocellulose thin film coating was demonstrated. The experimental results showed that the lens had a total gain of 20 dB and an angular beamwidth of 2.9 degrees when connected to a waveguide, which agreed well with microwave simulations. The proposed lens structure has advantages such as small volume, ultralight weight, and a 60 GHz bandwidth, making it particularly suitable for radio front-ends of future 6G devices.
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2023)
Article
Physics, Multidisciplinary
Junyi Wang, Jiaqi Yang, Guoguo Kang
Summary: This article introduces a novel design of single-layered achromatic phase Fresnel zone plate, which can achieve a large numerical aperture in the visible range, showing promising potential for various applications.
Article
Optics
Marjan Golbandi, Arash Sabatyan
Summary: This work introduces a technique based on a helically modulated petal zone plate for handling topological charge. The total topological charge of the generated beam depends on the difference between the number of the petal and the charge of the element, leading to a focused vortex beam turning into a focal spot. Additionally, a bi-annular vortex is generated with a large amount of petal frequency, forming an optical corridor carrying a topological charge around the focus.
OPTICS AND LASER TECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Eviatar Minerbi, Symeon Sideris, Jacob B. Khurgin, Tal Ellenbogen
Summary: We study the nonlinear THz emission from plasmonic metasurfaces and find that a thin ITO film significantly affects the system's nonlinear dynamics. The presence of the ITO film leads to a much stronger THz emission compared to a metasurface on glass, with a different dominant emission mechanism. The hot-electron dynamics in the system strongly modify the coupling between the metasurface and the free electrons in the ITO, resulting in dynamic THz emission phenomena that were not observed before.
Article
Nanoscience & Nanotechnology
Symeon Sideris, Eviatar Minerbi, Cormac McDonnell, Tal Ellenbogen
Summary: Strong single-cycle THz emission has been achieved from nonlinear plasmonic metasurfaces by exciting them with femtosecond laser pulses. The use of indium-tin-oxide (ITO) films with epsilon-near zero (ENZ) behavior in the excitation wavelength range has enhanced the nonlinear conversion. However, the THz conductivity of the ITO film reduces the radiation efficiency of the meta-atoms. To overcome this, the ITO layer around the plasmonic meta-atoms is etched, allowing the harnessing of enhanced localized fields while improving the THz radiation efficiency. This fabrication scheme presents important progress in expanding the applications of nonlinear plasmonic metasurface THz emitters.
