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Functional plastic films:nano-engineered composite based flexible microwave antennas with near-unity relative visible transmittance

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light(Advanced Manufacturing) 2024年第2期5卷 95-105页

作者： Cheng Zhang liang Zhu Chengang Ji Zhilu Ye Nabeel Alsaab Minye Yang Yuhui Hu Pai-Yen Chen l.jay guo School of Optical and Electronic Information&Wuhan National laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan430074China Department of Electrical and Computer Engineering University of Illinois at ChicagoChicagoIL 60607USA Department of Electrical Engineering and Computer Science University of MichiganAnn ArborMI 48109USA

Microwave antennas are essential elements for various applications,such as telecommunication,radar,sensing,and wireless power *** antennas are conventionally manufactured on rigid substrates using opaque materials,such as metal strips,metallic tapes,or epoxy pastes;thus,prohibiting their use in flexible and wearable devices,and simultaneously limiting their integration into existing optoelectronic ***,we demonstrate that mechanically flexible and optically transparent microwave antennas with high operational efficiencies can be readily fabricated using composite nanolayers deposited on common plastic *** composite nanolayer structure consists of an ultra-thin copper-doped silver film sandwiched between two dielectric films of tantalum pentoxide and aluminum *** material and thickness of each constituent layer are judiciously selected such that the whole structure exhibits an experimentally measured averaged visible transmittance as high as 98.94%compared to a bare plastic substrate,and simultaneously,a sheet resistance as low as 12.5Ω/*** representative types of microwave antennas are implemented:an omnidirectional dipole antenna,unidirectional Yagi-Uda antenna,low-profile patch antenna,and Fabry-Pérot cavity *** devices exhibit great mechanical flexibility with bending angle over 70°,high gain of up to 13.6 dBi,and large radiation efficiency of up to 84.5%.The proposed nano-engineered composites can be easily prepared over large areas on various types of substrates and simultaneously overcome the limitations of poor mechanical flexibility,low electrical conductivity,and reduced optical transparency usually faced by other constituent materials for flexible transparent microwave *** demonstrated flexible microwave antennas have various applications ranging from fifth-generation and vehicular communication systems to bio-signal monitors and wearable electronics.

关键词： Optically transparent antenna Flexible microwave antenna Transparent conductor Ultra-thin silver Doped silver Wearable optoelectronics

Optical enhancement effects of plasmonic nanostructures on organic photovoltaic cells

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Chinese Chemical letters 2015年第4期26卷 419-425页

作者： Hui Joon Park l.jay guo Division of Energy Systems Research Ajou University Department of Electrical Engineering and Computer Science University of Michigan

In this article, the optical enhancement effects of plasmonic nanostructures on OPV cells were reviewed as an effective way to resolve the mismatch problems between the short exciton diffusion length in organic semiconductors （around 10 nm） and the large thickness required to fully absorb sunlight （e.g. hundreds of nanometers）. Especially, the performances of OPVs with plasmonic nanoparticles in photoactive and buffer layers and with periodic nanostructures were investigated. Furthermore, nanoimprint lithography-based nanofabrication processes that can easily control the dimension and uniformity of structures for large-area and uniform I^lasmonic nanostructures were demonstrated.

关键词： Organic photovoltaicPlasmonic nanostructureNanoparticleNanogratingNanoimprint lithography

Inverse design of metasurface optical filters using deep neural network with highdegrees of freedom

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InfoMat 2021年第4期3卷 432-442页

作者： Xiao Han Ziyang Fan Zeyang liu Chao li l.jay guo Department of Electrical Engineering and Computer Science The University of MichiganAnn ArborMichigan Department of Information Science and Electronic Engineering Zhejiang UniversityHangzhouChina

In order to obtain a metasurface structure capable of filtering light of a specific wavelength range in the visible band,the traditional methods usually traverse the space consisting of possible designs,searching for a potenti ally satisfactory structure by performing iterative calculations to solve Maxwell's *** this article,we propose a systematic method based on neural networks that can complete an inverse design process to solve the *** with the traditional methods,our method is much faster while competent to encom-pass a high degree of freedom to generate device structures,which can ensure that the spectra of generated structures resemble the desired ones.

关键词： high degrees of freedom metasurface filter neural network visible band

Decorative near-infrared transmission filters featuring high-efficiency and angular-insensitivity employing ID photonic crystals

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Nano Research 2019年第3期12卷 543-548页

作者： Chengang Ji Chenying Yang Weidong Shen Kyu-Tae lee Yueguang Zhang Xu liu l.jay guo Department of Electrical Engineering and Computer Science The University of Michigan Ann Arbor Michigan 48109 USA State Key laboratory of Modern Optical Instrumentation Department of Optical Engineering Zhejiang University Hangzhou 310027 China Department of Physics Inha University Incheon 22212 Republic of Korea

We present a new scheme for visibly-opaque but near-infrared-transmitting filters involving 7 layers based on one-dimensional ternary photonic crystals, with capabilities in reaching nearly 100% transmission efficiency in the near-infrared region. Different decorative reflection colors can be created by adding additional three layers while maintaining the near-infrared transmission performance. In addition, our proposed structural colors show great angular insensitivity up to ±60° for both transverse electric and transverse magnetic polarizations, which are highly desired in various fields. The facile strategy described here involves a simple deposit!on method for the fabrication, thereby having great potential in diverse applications such as image sensors, anti-counterfeit tag, and optical measurement systems.

关键词： near-infrared (NIR)-transmitting filters colored decorations photonic crystals multilayer structures

Benchmarking deep learning-based models on nanophotonic inverse design problems

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Opto-Electronic Science 2022年第1期1卷 37-51页

作者： Taigao Ma Mustafa Tobah Haozhu Wang l.jay guo Department of Physics The University of MichiganAnn ArborMichigan48109USA Department of Materials Science and Engineering The University of MichiganAnn ArborMichigan48109USA Department of Electrical Engineering and Computer Science The University of MichiganAnn ArborMichigan48109USA

Photonic inverse design concerns the problem of finding photonic structures with target optical ***,traditional methods based on optimization algorithms are time-consuming and computationally ***,deep learning-based approaches have been developed to tackle the problem of inverse design *** most of these neural network models have demonstrated high accuracy in different inverse design problems,no previous study has examined the potential effects under given constraints in ***,the relative strength of different deep learning-based inverse design approaches has not been fully ***,we benchmark three commonly used deep learning models in inverse design:Tandem networks,Variational Auto-Encoders,and Generative Adversarial *** provide detailed comparisons in terms of their accuracy,diversity,and *** find that tandem networks and Variational Auto-Encoders give the best accuracy,while Generative Adversarial Networks lead to the most diverse *** findings could serve as a guideline for researchers to select the model that can best suit their design criteria and fabrication *** addition,our code and data are publicly available,which could be used for future inverse design model development and benchmarking.

关键词： inverse design photonics machine learning neural networks generative models

Quasi-vertical tapers for polymer-waveguide-based interboard optical interconnects

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Photonics Research 2015年第6期3卷 317-323页

作者： Zeyu Pan Harish Subbaraman Yi Zou Xiaochuan Xu Xingyu Zhang Cheng Zhang Qiaochu li l.jay guo Ray T.Chen Microelectronic Research Center Department of Electrical and Computer EngineeringThe University of Texas at AustinAustinTexas 78758USA Omega Optics Inc.8500 Shoal Creek BlvdAustinTexas 78757USA Department of Electrical Engineering and Computer Science University of Michigan1301 Beal AveAnn ArborMichigan 48109USA

A mode transformer based on the quasi-vertical taper is designed to enable high coupling efficiency for interboardlevel optical interconnects involving single-mode polymer waveguides and standard single-mode fibers. A triangular region fabricated above the waveguide is adopted to adiabatically transform the mode from the fiber into the polymer waveguide. The effects of the geometrical parameters of the taper, including width, height, tip width,etc., on the coupling efficiency are numerically investigated. Based on this, a quasi-vertical taper for the polymer rib waveguide system is designed, fabricated, and characterized. Coupling losses of 1.79 0.30 and 2.23 0.31 dB per coupler for the quasi-TM and quasi-TE mode, respectively, are measured across the optical communication C and l bands(1535 to 1610 nm). low-cost packaging, leading to widespread utilization of polymeric photonicdevices, is envisioned for optical interconnect applications.

关键词： mode MFD Quasi-vertical tapers for polymer-waveguide-based interboard optical interconnects TE

使用微环谐振器和激光产生的超声聚焦的超声检测和成像

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光学与光电技术 2019年第6期17卷 1-5页

作者： l.jay guo 密歇根大学电子工程与计算机科学系

超声的光学检测是基于应变场与光场的相互作用的新兴技术,通过调节谐振腔的光学特性进行高灵敏检测。与传统的压电换能器相比,这种检测方案具有宽频带响应,以及灵敏度与尺寸无关的优点。检测器的高灵敏度对于较深的穿透深度至关重要,特... 详细信息

超声的光学检测是基于应变场与光场的相互作用的新兴技术,通过调节谐振腔的光学特性进行高灵敏检测。与传统的压电换能器相比,这种检测方案具有宽频带响应,以及灵敏度与尺寸无关的优点。检测器的高灵敏度对于较深的穿透深度至关重要,特别是对于高分辨率成像,因为检测物对高频超声波有强衰减。此外,小器件尺寸具有在超声检测中实现宽接受角的优势。介绍了基于聚合物光子微环谐振器的超声波高灵敏度和宽带检测,并展示其在高分辨率光声层析与光声显微技术中的应用。类似原理还可应用于太赫兹检测,微环可以"听到"吸收太赫兹能量的纳米材料产生的声波。还介绍了产生和聚焦超声波的薄膜光学发射器,用于强振幅聚焦超声成像与治疗。光声源由碳纳米管和弹性体聚合物制成。纳米复合材料作为优异的光吸收器和高效的热转化器,可以产生具有强振幅的输出压力,并具有显示出高频特性的对应频谱。这种方法可以为收集和图形化等细胞工程提供多功能的工具,更重要的是,非热破坏裂可以促进靶向细胞的药物输运与基因治疗。

关键词：微环谐振腔超声的光学检测太赫兹检测超声手术刀

A Method for Evaluating the Maximum Bending Degree of Flexural Toppling Rock Masses Based on the Rock Tensile Strain-Softening Model

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Journal of Earth Science 2024年第4期35卷 1243-1253页

作者： Jiongchao Wang Jun Zheng Jichao guo Qing lü Jianhui Deng Department of Civil Engineering Zhejiang UniversityHangzhou310058China Center for Balance Architecture Zhejiang UniversityHangzhou310007China State Key laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China

Flexural toppling occurs when a series of layered rock masses bend towards their free *** is important to evaluate the maximum bending degree and the requirement of supports of flexural toppling rock mass to prevent rock mass cracking and even failure leading to a *** on the rock tensile strain-softening model,this study proposes a method for calculating the maximum curvature(C_(ppmax))of flexural toppling rock *** applying this method to calculate Cppmax of 9 types of rock masses with different hardness and rock layer thickness,some conclusions are drawn:(1)the internal key factors affecting C_(ppmax)are E^(⋆)(E^(⋆)=E_(ss)/E_(0),where E_(0)and E_(ss)are the mean deformation moduli of the rock before and after reaching its peak tensile strength,respectively),the strainεt corresponding to the tensile strength of rock,and the thickness(h)of rock layers;(2)hard rock layers are more likely to develop into block toppling than soft rock layers;and(3)thin rock layers are more likely to remain in flexural toppling state than thick rock *** addition,it is found that C_(ppmax)for flexural toppling rock masses composed of bedded rocks such as gneiss is related to the tensile direction.

关键词： flexural toppling rock mass maximum bending degree strain-softening model curvature rock mechanics

Pulsations of Three Rapidly Oscillating Ap Stars TIC 96315731,TIC72392575,and TIC 318007796

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Research in Astronomy and Astrophysics 2024年第8期24卷 157-168页

作者： Hai-Jian Zhong Dong-Xiang Shen Chun-Hua Zhu He-lei liu Su-Fen guo guo-liang lü School of Physical Science and Technology Xinjiang UniversityUrumqi 830046China Xinjiang Astronomical Observatory National Astronomical ObservatoriesChinese Academy of SciencesUrumqi 830000China

We analyze the frequencies of three known roAp stars,TIC 96315731,TIC 72392575,and TIC 318007796,using the light curves from the Transiting Exoplanet Survey *** TIC 96315731,the rotational and pulsational frequencies are 0.1498360 day^(-1)and 165.2609 day^(-1),*** the case of TIC 72392575,the rotational frequency is 0.25551 day^(-1).We detect a quintuplet of pulsation frequencies with a center frequency of135.9233 day^(-1),along with two signals within the second pair of rotational sidelobes of the quintuplet separated by the rotation *** two signals may correspond to the frequencies of a dipole *** TIC318007796,the rotational and pulsational frequencies are 0.2475021 day^(-1),192.73995 day^(-1),and196.33065 day^(-1),*** on the oblique pulsator model,we calculate the rotation inclination(i)and magnetic obliquity angle(b)for the stars,which provide the geometry of the pulsation *** the phases of the frequency quintuplets,the pulsation amplitude and phase modulation curves,and the results of spherical harmonic decomposition,we conclude that the pulsation modes of frequency quintuplets in TIC96315731,TIC 72392575,and TIC 318007796 correspond to distorted dipole mode,distorted quadrupole mode,and distorted dipole mode,respectively.

关键词： asteroseismology-techniques photometric-stars oscillations(including pulsations)-stars chemically peculiar