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基于聚类的激光器频率稳定性研究
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作者 吴强 陈君航 古龙毅 《工业控制计算机》 2024年第7期85-87,90,共4页
激光器的频率稳定性和精确控制对于许多应用来说至关重要,包括光通信、光谱分析、激光加工和科学研究。针对温度等环境因素容易导致激光器的激光频率变化,为此设计了一种监控方法,能够快速地监控不同环境干扰下的激光的频率变化。根据Ta... 激光器的频率稳定性和精确控制对于许多应用来说至关重要,包括光通信、光谱分析、激光加工和科学研究。针对温度等环境因素容易导致激光器的激光频率变化,为此设计了一种监控方法,能够快速地监控不同环境干扰下的激光的频率变化。根据Talbot成像,从单个视角通过GLCM特征提取,对特征数据使用改进后的T-EWNMF-L1处理,使用Kmeans聚类,能够实现很好的准确度。 展开更多
关键词 激光器频率 工作波长 talbot 聚类
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Talbot effect in anti-PT symmetric synthetic photonic lattices
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作者 刘兆峰 唐思维 +3 位作者 温增润 高垣梅 蔡阳健 郑立仁 《Chinese Optics Letters》 SCIE EI CAS CSCD 2024年第3期107-111,共5页
We investigated the Talbot effect in an anti-parity-time(PT)symmetric synthetic photonic lattice composed of two coupled fiber loops.We calculated the band structures and found that with an increase in the gain-loss p... We investigated the Talbot effect in an anti-parity-time(PT)symmetric synthetic photonic lattice composed of two coupled fiber loops.We calculated the band structures and found that with an increase in the gain-loss parameter,the band transitions from a real spectrum to a complex spectrum.We study the influence of phase in the Hermitian operator on the Talbot effect,and the Talbot effect disappears when the period of the input field is N>8.Further study shows that the variation of Talbot distance can also be modulated by non-Hermitian coefficients of gain and loss.This work may find significant applications in pulse repetition-rate multiplication,temporal invisibility,and tunable intensity amplifiers. 展开更多
关键词 talbot effect synthetic dimensions anti-PT symmetry photonic lattices
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一种基于泰伯子像的光刻系统并由期望图案设计掩膜板的方法
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作者 荣南楠 张宝昊 +3 位作者 何张登 刘帅 李凯强 吕俊君 《集成电路应用》 2019年第11期5-7,共3页
提出一种基于泰伯效应利用泰伯子像实现光刻,并利用反演光刻技术由期望图案设计掩膜板的方 法。泰伯子像是在分数倍泰伯距离上出现的一种像元倍增且呈棋盘状分布的自成像。根据菲涅耳衍射理 论分析可知,泰伯子像是两种泰伯像在同一平面... 提出一种基于泰伯效应利用泰伯子像实现光刻,并利用反演光刻技术由期望图案设计掩膜板的方 法。泰伯子像是在分数倍泰伯距离上出现的一种像元倍增且呈棋盘状分布的自成像。根据菲涅耳衍射理 论分析可知,泰伯子像是两种泰伯像在同一平面的叠加,像元数量是两种泰伯像像元之和,即像元倍 增,由于叠加的两种泰伯像相位差 180°,呈现出棋盘状分布的现象。基于泰伯子像的成像现象,研究一 种掩膜板设计方法,针对一些特定的工艺窗口,将其转化为期望图案,由期望图案利用反演光刻技术设 计掩膜板图案。将期望的图案作为泰伯子像的结果利用反演算法推算出掩膜板的图案分布以及参数。 展开更多
关键词 泰伯效应 泰伯子像 掩膜板 talbot 光刻机
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Accordion lattice based on the Talbot ef fect 被引量:3
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作者 S.Deachapunya S.Srisuphaphon 《Chinese Optics Letters》 SCIE EI CAS CSCD 2014年第3期22-25,共4页
We introduce an idea of producing an optical lattice relied on the Talbot effect. Our alternative scheme is based on the interference of light behind a diffraction grating in the near-field regime. We demonstrate 1D a... We introduce an idea of producing an optical lattice relied on the Talbot effect. Our alternative scheme is based on the interference of light behind a diffraction grating in the near-field regime. We demonstrate 1D and 2D optical lattices with the simulations and experiments. This Talbot optical lattice can be broadly used from quantum simulations to quantum information. The Talbot effect is usually used in lensless optical systems, therefore it provides small aberrations. 展开更多
关键词 Accordion lattice based on the talbot ef fect
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柱面光栅Talbot效应
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作者 叶庆卫 《宁波大学学报(理工版)》 CAS 1991年第1期119-123,共5页
本文在傍轴近似下,导出了柱面波照射下柱面光栅的Talbot自成象一般公式。它与在球面波照射下平面光栅的自成象规律类似。此一般公式在极限情况下,可退化出已知的平面光栅成象公式。
关键词 talbot 效应 柱面波 柱面光栅
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Geometrical condition for observing Talbot effect in plasmonics infinite metallic groove arrays
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作者 Xiao-Ping Lou Ming-Li Dong +2 位作者 Chuan-Bo Li Shuai Feng Lian-Qing Zhu 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第12期291-296,共6页
The plasmonics Talbot effect in metallic layer with infinite periodic grooves is presented in this study. Numerical approach based on the finite element method is employed to verify the derived Talbot carpet on the no... The plasmonics Talbot effect in metallic layer with infinite periodic grooves is presented in this study. Numerical approach based on the finite element method is employed to verify the derived Talbot carpet on the non-illumination side. The groove depth is less than the metallic layer thickness; however, for specific conditions, surface plasmons polaritons(SPPs)can penetrate through grooves, propagate under the metallic layer, and form Talbot revivals. The geometrical parameters are specified via groove width, gap size, period, and wavelength, and their proper values are determined by introducing two opening ratio parameters. To quantitatively compare different Talbot carpets, we introduce new parameters such as R-square that characterizes the periodicity of Talbot images. The higher the R-square of a carpet, the more coincident with non-paraxial approximation the Talbot distance becomes. We believe that our results can help to understand the nature of SPPs and also contribute to exploring this phenomenon in Talbot-image-based applications, including imaging, optical systems, and measurements. 展开更多
关键词 talbot image surface plasmon polaritons groove array
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Simple phase extraction in x-ray differential phase contrast imaging
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作者 刘鑫 郭金川 +2 位作者 雷耀虎 李冀 牛憨笨 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第2期563-567,共5页
A fast and simple method to extract phase-contrast images from interferograms is proposed, and its effectiveness is demonstrated through simulation and experiment. For x-ray differential phase contrast imaging, a stro... A fast and simple method to extract phase-contrast images from interferograms is proposed, and its effectiveness is demonstrated through simulation and experiment. For x-ray differential phase contrast imaging, a strong attenuation signal acts as an overwhelming background intensity that obscures the weak phase signal so that no obvious phase-gradient information is detectable in the raw image. By subtracting one interferogram from another, chosen at particular intervals,the phase signal can be isolated and magnified. 展开更多
关键词 x-ray imaging x-ray interferometry talbot and self-imaging effects phase contrast imaging
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Occurrence of Features of Fiber Bragg Grating Spectra Having a Wavelength Corresponding to the Phase Mask Periodicity
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作者 Sui P. Yam Zourab Brodzeli +2 位作者 Scott A. Wade Greg W. Baxter Stephen F. Collins 《Journal of Electronic Science and Technology of China》 2008年第4期458-461,共4页
The use of a phase mask with 536 nm uniform pitch allowed the fabrication of a fiber Bragg grating for use at a Bragg wavelength of 785 nm. Reflection and transmission features at 1552 nm, twice the Bragg wavelength, ... The use of a phase mask with 536 nm uniform pitch allowed the fabrication of a fiber Bragg grating for use at a Bragg wavelength of 785 nm. Reflection and transmission features at 1552 nm, twice the Bragg wavelength, associated with the phase mask periodicity were observed. However, when phase mask orders other than +1 were absent during fabrication the features at 1552 nm were not evident. 展开更多
关键词 Double of the Bragg wavelength fiber Bragg grating phase mask talbot interferometer.
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Preliminary research on dual-energy X-ray phase-contrast imaging
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作者 韩华杰 王圣浩 +5 位作者 高昆 王志立 张灿 杨萌 张凯 朱佩平 《Chinese Physics C》 SCIE CAS CSCD 2016年第4期141-148,共8页
Dual-energy X-ray absorptiometry(DEXA) has been widely applied to measure the bone mineral density(BMD) and soft-tissue composition of the human body. However, the use of DEXA is greatly limited for lowZ materials... Dual-energy X-ray absorptiometry(DEXA) has been widely applied to measure the bone mineral density(BMD) and soft-tissue composition of the human body. However, the use of DEXA is greatly limited for lowZ materials such as soft tissues due to their weak absorption, while X-ray phase-contrast imaging(XPCI) shows significantly improved contrast in comparison with the conventional standard absorption-based X-ray imaging for soft tissues. In this paper, we propose a novel X-ray phase-contrast method to measure the area density of low-Z materials, including a single-energy method and a dual-energy method. The single-energy method is for the area density calculation of one low-Z material, while the dual-energy method aims to calculate the area densities of two low-Z materials simultaneously. Comparing the experimental and simulation results with the theoretical ones, the new method proves to have the potential to replace DEXA in area density measurement. The new method sets the prerequisites for a future precise and low-dose area density calculation method for low-Z materials. 展开更多
关键词 DEXA refraction replace grating pixel talbot sorption downstream precise listed
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The Numerical Inversion of the Laplace Transform in a Multi-Precision Environment
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作者 Colin L. Defreitas Steve J. Kane 《Applied Mathematics》 2022年第5期401-418,共18页
This paper examines the performance of five algorithms for numerically inverting the Laplace transform, in standard, 16-digit and multi-precision environments. The algorithms are taken from three of the four main clas... This paper examines the performance of five algorithms for numerically inverting the Laplace transform, in standard, 16-digit and multi-precision environments. The algorithms are taken from three of the four main classes of numerical methods used to invert the Laplace transform. Because the numerical inversion of the Laplace transform is a perturbed problem, rounding errors which are generated in numerical approximations can adversely affect the accurate reconstruction of the inverse transform. This paper demonstrates that working in a multi-precision environment can substantially reduce these errors and the resulting perturbations exist in transforming the data from the s-space into the time domain and in so doing overcome the main drawback of numerically inverting the Laplace transform. Our main finding is that both the Talbot and the accelerated Gaver functionals perform considerably better in a multi-precision environment increasing the advantages of using Laplace transform methods over time-stepping procedures in solving diffusion and more generally parabolic partial differential equations. 展开更多
关键词 Laplace Transform PERTURBATION Numerical Inversion Multi-Precision Stehfest talbot
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Nonuniform self-imaging of achromatic Talbot lithography 被引量:2
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作者 Huijuan Xia Shumin Yang +4 位作者 Liansheng Wang Jun Zhao Chaofan Xue Yanqing Wu Renzhong Tai 《Chinese Optics Letters》 SCIE EI CAS CSCD 2019年第6期75-79,共5页
Achromatic Talbot lithography(ATL)with high resolution has been demonstrated to be an excellent technique for large area periodic nano-fabrication.In this work,the uniformity of pattern distribution in ATL was studied... Achromatic Talbot lithography(ATL)with high resolution has been demonstrated to be an excellent technique for large area periodic nano-fabrication.In this work,the uniformity of pattern distribution in ATL was studied in detail.Two ATL transmission masks with^50%duty cycle in a square lattice were illuminated by a spatial coherent broadband extreme ultraviolet beam with a relative bandwidth of 2.38%.Nonuniform dot size distribution was observed by experiments and finite-difference time-domain simulations.The sum of the two kinds of diffraction patterns,with different lattice directions(45°rotated)and different intensity distributions,results in the final nonuniform pattern distribution. 展开更多
关键词 ACHROMATIC talbot LITHOGRAPHY HAS been demonstrated NONUNIFORM PATTERN distribution
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光栅二次衍射及其在精密定位中的应用 被引量:1
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作者 贾惠波 徐振明 廖艳姣 《仪器仪表学报》 EI CAS 1984年第4期68-72,共5页
本文描述了平行光束经两个光栅依次衍射后的强度随着两个光栅的相对位移而发生变化,分析了光栅间距与这个变化的对比度的关系。提出了一种基于调制搜索原理检测二次衍射零级光强实现高灵敏度、亚微米级精密定位的方法,给出了灵敏度0.1... 本文描述了平行光束经两个光栅依次衍射后的强度随着两个光栅的相对位移而发生变化,分析了光栅间距与这个变化的对比度的关系。提出了一种基于调制搜索原理检测二次衍射零级光强实现高灵敏度、亚微米级精密定位的方法,给出了灵敏度0.1μm,重复定位精度0.2μm 的实验结果。 展开更多
关键词 精密定位 重复定位精度 平行光束 亚微米级 光强 零级 talbot 光电信号 光电元件 周期变化
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Nonlinear Talbot self-healing in periodically poled LiNbO_3 crystal [Invited] 被引量:1
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作者 Bingxia Wang Shan Liu +4 位作者 Tianxiang Xu Ruwei Zhao Peixiang Lu Wieslaw Krolikowski Yan Sheng 《Chinese Optics Letters》 SCIE EI CAS CSCD 2021年第6期50-53,共4页
The nonlinear Talbot effect is a near-field nonlinear diffraction phenomenon in which the self-imaging of periodic objects is formed by the second harmonics of the incident laser beam. We demonstrate the first, to the... The nonlinear Talbot effect is a near-field nonlinear diffraction phenomenon in which the self-imaging of periodic objects is formed by the second harmonics of the incident laser beam. We demonstrate the first, to the best of our knowledge, example of nonlinear Talbot self-healing, i.e., the capability of creating defect-free images from faulty nonlinear optical structures. In particular, we employ the tightly focused femtosecond infrared optical pulses to fabricate LiNbO_(3) nonlinear photonic crystals and show that the defects in the form of the missing points of two-dimensional square and hexagonal periodic structures are restored in the second harmonic images at the first nonlinear Talbot plane. The observed nonlinear Talbot self-healing opens up new possibilities for defect-tolerant optical lithography and printing. 展开更多
关键词 nonlinear talbot effect nonlinear photonic crystal periodically poled LiNbO_(3) second harmonic generation SELF-HEALING
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Scalable Talbot effect of periodic array objects 被引量:1
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作者 Rui Yang Zhenfa Xue +2 位作者 Zhiyong Shi Liqiang Zhou Linwei Zhu 《Chinese Optics Letters》 SCIE EI CAS CSCD 2020年第3期6-10,共5页
A type of scalable self-imaging capable of variable magnification or minification of periodic objects is demonstrated in the focal plane of a lens illuminated by a point source.The theory and the experimental results ... A type of scalable self-imaging capable of variable magnification or minification of periodic objects is demonstrated in the focal plane of a lens illuminated by a point source.The theory and the experimental results show that the self-imaging phenomenon can also be realized in the focal plane of a lens regardless of whether the distances satisfy the lens formula or not.The particular property of this scalable self-imaging effect is that the images in the focal plane can be controlled with different scaling factors only when the distances between the point source and the periodic object satisfy a certain condition.This discovery should open a new field of diffraction imaging and new application opportunities in precision measurement. 展开更多
关键词 talbot effect PERIODIC OBJECT DIFFRACTION theory LENS
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Temporal Airy–Talbot effect in linear optical potentials 被引量:1
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作者 Tianwen Han Hao Chen +2 位作者 Wenwan Li Bing Wang Peixiang Lu 《Chinese Optics Letters》 SCIE EI CAS CSCD 2021年第8期105-110,共6页
We investigate the Airy–Talbot effect of an Airy pulse train in time-dependent linear potentials.The parabolic trajectory of self-imaging depends on both the dispersion sign and the linear potential gradient.By impos... We investigate the Airy–Talbot effect of an Airy pulse train in time-dependent linear potentials.The parabolic trajectory of self-imaging depends on both the dispersion sign and the linear potential gradient.By imposing linear phase modulations on the pulse train,the Airy–Talbot effects accompanied with positive and negative refractions are realized.For an input composed of stationary Airy pulses,the self-imaging follows straight lines,and the Airy–Talbot distance can be engineered by varying the linear potential gradient.The effect is also achieved in symmetric linear potentials.The study provides opportunities to control the self-imaging of aperiodic optical fields in time dimension. 展开更多
关键词 Airy pulse talbot and self-imaging effect DISPERSION linear potential
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Talbot剪切干涉仪及其应用 被引量:1
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作者 罗懿祖 王伟建 《中国激光》 EI CAS 1983年第4期225-229,共5页
本文提出了提高Talbot剪切干涉仪检测精度的原理及方法。给出了棱镜、透镜等光学元件及相位物体的检测及其各级滤波剪切干涉象。最后给出了与理论一致的实验结果。
关键词 傅里叶变换透镜 检测精度 剪切量 talbot 剪切干涉仪 光强度分布 衍射级 光栅 棱镜顶角
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On the Approximation of Fractal-Fractional Differential Equations Using Numerical Inverse Laplace Transform Methods
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作者 Kamran Siraj Ahmad +2 位作者 Kamal Shah Thabet Abdeljawad Bahaaeldin Abdalla 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第6期2743-2765,共23页
Laplace transform is one of the powerful tools for solving differential equations in engineering and other science subjects.Using the Laplace transform for solving differential equations,however,sometimes leads to sol... Laplace transform is one of the powerful tools for solving differential equations in engineering and other science subjects.Using the Laplace transform for solving differential equations,however,sometimes leads to solutions in the Laplace domain that are not readily invertible to the real domain by analyticalmeans.Thus,we need numerical inversionmethods to convert the obtained solution fromLaplace domain to a real domain.In this paper,we propose a numerical scheme based on Laplace transform and numerical inverse Laplace transform for the approximate solution of fractal-fractional differential equations with orderα,β.Our proposed numerical scheme is based on three main steps.First,we convert the given fractal-fractional differential equation to fractional-differential equation in Riemann-Liouville sense,and then into Caputo sense.Secondly,we transformthe fractional differential equation in Caputo sense to an equivalent equation in Laplace space.Then the solution of the transformed equation is obtained in Laplace domain.Finally,the solution is converted into the real domain using numerical inversion of Laplace transform.Three inversion methods are evaluated in this paper,and their convergence is also discussed.Three test problems are used to validate the inversion methods.We demonstrate our results with the help of tables and figures.The obtained results show that Euler’s and Talbot’s methods performed better than Stehfest’s method. 展开更多
关键词 Fractal-fractional differential equation power law kernel exponential decay kernel Mittag-Leffler kernel Laplace transform Euler’s method talbot’s method Stehfest’s method
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Talbot effect in nonparaxial self- accelerating beams with electromagnetically induced transparency 被引量:1
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作者 Jing-Min Ru Zhen-Kun Wu +2 位作者 Ya-Gang Zhang Feng Wen Yu-Zong Gu 《Frontiers of physics》 SCIE CSCD 2020年第5期137-143,共7页
In this study,we report on the fractional Talbot ffect of nonpar axial self-accelerating beams in a multilevel electromagnetically induced transparency(EIT)atomic configuration,which,to the best of our knowledge,is th... In this study,we report on the fractional Talbot ffect of nonpar axial self-accelerating beams in a multilevel electromagnetically induced transparency(EIT)atomic configuration,which,to the best of our knowledge,is the first study on this subject.The Tallbot ffect originates from superposed eigenmodes of the Helmholtz equation and forms in the EIT window in the presence of both linear and cubic susceptibilities.The Talbot ffect can be realized by appropriately selecting the cofficients of the beam components.Our results indicate that the larger the radial difference between beam components,the stronger the interference between them,the smaller the Tallbot angle is.The results of this study can be useful when studying optical imaging.optical measurements,and optical computing. 展开更多
关键词 multilevel atomic configuration nonparaxial self-accelerating beam talbot effect electromagnetically induced transparency
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Two-Dimensional Talbot Effect with Atomic Density Gratings
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作者 李辰 周天伟 +5 位作者 项晶罡 翟跃阳 乐旭广 杨仕锋 熊炜 陈徐宗 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第8期79-82,共4页
We report the experimental observation of two-dimensional Talbot effect when a resonance plane wave interacts with a two-dimensional atomic density grating generated by standing wave manipulation of ultracold Bose gas... We report the experimental observation of two-dimensional Talbot effect when a resonance plane wave interacts with a two-dimensional atomic density grating generated by standing wave manipulation of ultracold Bose gases. Clear self-images of the grating and sub-images with reversed phase or fractal patterns are observed. By calculating the autocorrelation functions of the images, the behavior of periodic Talbot images is studied. The Talbot effect with two-dimensional atomic density grating expands the applications of the Talbot effect in a wide variety of research fields. 展开更多
关键词 Two-Dimensional talbot Effect with Atomic Density Gratings
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Conformally Mapped Multifunctional Acoustic Metamaterial Lens for Spectral Sound Guiding and Talbot Effect
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作者 He Gao Xinsheng Fang +4 位作者 Zhongming Gu Tuo Liu Shanjun Liang Yong Li Jie Zhu 《Research》 EI CAS 2019年第1期299-308,共10页
We demonstrate a conformally mapped multifunctional acoustic metamaterial Mikaelian lens.Mikaelian lens is a gradient medium with a hyperbolic secant refractive index profile that can realize functions like beam self-... We demonstrate a conformally mapped multifunctional acoustic metamaterial Mikaelian lens.Mikaelian lens is a gradient medium with a hyperbolic secant refractive index profile that can realize functions like beam self-focusing.Unlike the conventional design approaches,with a conformal transformation method,only isotropic material parameters with gradient refractive index profiles are required for the construction of such lens.To realize desired gradient index distribution,we carefully design a new type of crosschannel-shaped acoustic metamaterial,whose refractive index can be effectively modulated by simply changing the slit opening size.The distinct capabilities of the metamaterial Mikaelian lens in manipulating acoustic waves are experimentally verified with the fabricated sample.Simultaneous sound guiding and Talbot effects,which normally require respective geometrical and wave acoustic approximations,are observed in simulations and experiments.Furthermore,those effects of shaping acoustic wave propagations were validated within a relatively wide frequency range.Our study reveals how the conformal transformation method can help to bridge the ray acoustics with wave acoustics.It offers opportunities to the development of novel multifunctional acoustic devices for various applications,such as sound and particle manipulations. 展开更多
关键词 talbot ACOUSTICS refractive
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