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Auswahl der wissenschaftlichen Literatur zum Thema „Tunable metasurface“
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Zeitschriftenartikel zum Thema "Tunable metasurface"
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Xu, Zhu-Long, Shi-Bo Yu, Junjie Liu, and Kuo-Chih Chuang. "A Tunable Zig-Zag Reflective Elastic Metasurface." Crystals 12, no. 8 (2022): 1170. http://dx.doi.org/10.3390/cryst12081170.
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In this paper, inspired by origami structures, we offer a very simple tuning method to overcome the limitations of general elastic metasurfaces, where only a certain functionality at a certain frequency range can be achieved, by designing a reflective metasurface based on foldable/deployable zig-zag structures. By utilizing peg/screw connections, the folding angles of the zig-zag structures can be easily tuned while also being fixable. By tuning the folding angle, the subunit of the zig-zag metasurface can cover a 2π phase shift span and the phase shift can be tuned continuously, and almost linearly, with respect to the folding angle. With a simple folding motion, the tunable reflective metasurface can steer reflected flexural waves in different directions and focus-reflected flexural waves with different focal distances. In addition to demonstrating tunable performance, the mechanism that associates the changing speed of the phase shift is explained. The proposed tunable zig-zag elastic metasurface provides a new way to design reconfigurable metamaterials/metasurfaces.
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Yang, Jingyi, Sudip Gurung, Subhajit Bej, Peinan Ni, and Ho Wai Howard Lee. "Active optical metasurfaces: comprehensive review on physics, mechanisms, and prospective applications." Reports on Progress in Physics 85, no. 3 (2022): 036101. http://dx.doi.org/10.1088/1361-6633/ac2aaf.
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Abstract Optical metasurfaces with subwavelength thickness hold considerable promise for future advances in fundamental optics and novel optical applications due to their unprecedented ability to control the phase, amplitude, and polarization of transmitted, reflected, and diffracted light. Introducing active functionalities to optical metasurfaces is an essential step to the development of next-generation flat optical components and devices. During the last few years, many attempts have been made to develop tunable optical metasurfaces with dynamic control of optical properties (e.g., amplitude, phase, polarization, spatial/spectral/temporal responses) and early-stage device functions (e.g., beam steering, tunable focusing, tunable color filters/absorber, dynamic hologram, etc) based on a variety of novel active materials and tunable mechanisms. These recently-developed active metasurfaces show significant promise for practical applications, but significant challenges still remain. In this review, a comprehensive overview of recently-reported tunable metasurfaces is provided which focuses on the ten major tunable metasurface mechanisms. For each type of mechanism, the performance metrics on the reported tunable metasurface are outlined, and the capabilities/limitations of each mechanism and its potential for various photonic applications are compared and summarized. This review concludes with discussion of several prospective applications, emerging technologies, and research directions based on the use of tunable optical metasurfaces. We anticipate significant new advances when the tunable mechanisms are further developed in the coming years.
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Peng, Yao-Yin, Jin-Heng Chen, Zhang-Zhao Yang, Xin-Ye Zou, Chao Tao, and Jian-Chun Cheng. "Broadband tunable acoustic metasurface based on piezoelectric composite structure with two resonant modes." Applied Physics Express 15, no. 1 (2022): 014004. http://dx.doi.org/10.35848/1882-0786/ac444a.
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Abstract In this letter, we propose a deep-wavelength tunable acoustic metasurface composed of a fixed piezoelectric composite structure with a broad operating frequency range. The metasurface unit has two tunable resonant frequencies determined by specific external inductors and can continuously modulate the phase of the transmitted wave. The influence of the inductors on resonant frequencies are studied by simulation and experiment. Moreover, the functions of acoustic beam steering and focusing by the designed metasurface at three arbitrarily chosen frequencies are verified in simulation. This work may have good potential in the design of acoustic metasurfaces with broadband operating frequencies.
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He, Shaowei, Huimin Yang, Yunhui Jiang, Wenjun Deng, and Weiming Zhu. "Recent Advances in MEMS Metasurfaces and Their Applications on Tunable Lens." Micromachines 10, no. 8 (2019): 505. http://dx.doi.org/10.3390/mi10080505.
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The electromagnetic (EM) properties of metasurfaces depend on both structural design and material properties. microelectromechanical systems (MEMS) technology offers an approach for tuning metasurface EM properties by structural reconfiguration. In the past 10 years, vast applications have been demonstrated based on MEMS metasurfaces, which proved to have merits including, large tunability, fast speed, small size, light weight, capability of dense integration, and compatibility of cost-effective fabrication process. Here, recent advances in MEMS metasurface applications are reviewed and categorized based on the tuning mechanisms, operation band and tuning speed. As an example, the pros and cons of MEMS metasurfaces for tunable lens applications are discussed and compared with traditional tunable lens technologies followed by the summary and outlook.
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Chen, Yankai, and Yi Wang. "Electrically tunable toroidal Fano resonances of symmetry-breaking dielectric metasurfaces using graphene in the infrared region." Journal of Optics 24, no. 4 (2022): 044012. http://dx.doi.org/10.1088/2040-8986/ac5836.
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Abstract The magnitudes of coupling strength play an important role in various resonant phenomena such as Fano resonances (FRs). However, the coupling strength within the FRs using dielectric metasurfaces cannot be easily manipulated once they have been made. In this paper, toroidal FR is excited using the silicon metasurface with symmetry-breaking nanocylinders. Inserting a graphene layer with an ion-gel top gate onto the silicon metasurface, actively tunable response of a toroidal FR resulting from the manipulated coupling strength and the phase shift between two states. The hybrid graphene-silicon metasurface realize tunable Fano parameter (q) from −1.38 to −1.85 with applied voltage ranging from 0 to 2 v. Theoretical results predicted that higher q values are reachable relying on the hybrid graphene-silicon metasurface. The high-quality(Q)-factor (∼444) tunable FR of metasurface in the near-infrared region is observed. By applying a bias voltage to graphene obtain a blueshift of resonant wavelength (∼4 nm) with a maximum change of transmission spectrum peak up to 30%. These results have potential in high-efficient tunable electro-optic modulators, near-infrared optical switches, etc.
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Li, Jing, Hongjie Fan, Han Ye, et al. "Design of Multifunctional Tunable Metasurface Assisted by Elastic Substrate." Nanomaterials 12, no. 14 (2022): 2387. http://dx.doi.org/10.3390/nano12142387.
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Metasurfaces with both multifunctionality and tunability hold great application potential in next-generation optical devices. In this paper, we propose a stretchable metasurface composed of arrays of identical dielectric rectangular resonators embedded in the polydimethylsiloxane (PDMS) substrate. It is shown that the metasurface possesses three functions at the operating wavelength of 532 nm. The switching of functions can be implemented by changing the period Px of the metasurface, induced by stretching the PDMS substrate along the x-direction. When the period Px is less than the operating wavelength of 532 nm, the behavior of metasurface can switch between transmissive window and reflective mirror. When the period Px of the metasurface varies from 532 nm to 700 nm, the metasurface act as a dynamic equal-power beam splitter with conversion efficiency higher than 90%, and the corresponding splitting angle can be adjusted from 90° to around 49.5°. Moreover, we achieve the switching of transmissive window/reflective mirror/split-ratio-variable splitter based on the metasurface consisting of arrays of identical L-shaped resonators embedded in the PDMS substrate.
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Wang, Ling, Weijun Hong, Li Deng, et al. "Reconfigurable Multifunctional Metasurface Hybridized with Vanadium Dioxide at Terahertz Frequencies." Materials 11, no. 10 (2018): 2040. http://dx.doi.org/10.3390/ma11102040.
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Driven by the continuous demand for system integration and device miniaturization, integrating multiple diversified functions into a single metasurface hybridized with the tunable metaparticle is highly demanding at terahertz (THz) range. However, up to now, because of the limitation of the tunable metaparticle at terahertz range, most of the metasurfaces feature a single function only or process similar functionalities at a single frequency. A reconfigurable multifunctional metasurface which can realize the switch of transmission and reflection and manipulate the linearized polarization state of electromagnetic waves simultaneously over a controllable terahertz frequency range based on the vanadium dioxide was designed for the first time in the paper. The numerical result demonstrates the validity of the appropriately designed metasurface. Simulation results show that the reconfigurable and multifunctional performance of this metasurface can be acquired over 1.59 THz to 1.74 THz without re-optimizing or re-fabricating structures, which effectively extends the operating frequencies. The proposed metasurface holds potential for electromagnetic wave manipulation and this study can motivate the realization of the wideband multifunctional metasurface and the software-driven reconfigurable metasurface at terahertz frequencies.
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Luo, Sisi, Jianjiao Hao, Fuju Ye, et al. "Evolution of the Electromagnetic Manipulation: From Tunable to Programmable and Intelligent Metasurfaces." Micromachines 12, no. 8 (2021): 988. http://dx.doi.org/10.3390/mi12080988.
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Looking back on the development of metamaterials in the past 20 years, metamaterials have gradually developed from three-dimensional complex electromagnetic structures to a two-dimensional metasurface with a low profile, during which a series of subversive achievements have been produced. The form of electromagnetic manipulation of the metasurface has evolved from passive to active tunable, programmable, and other dynamic and real-time controllable forms. In particular, the proposal of coding and programmable metasurfaces endows metasurfaces with new vitality. By describing metamaterials through binary code, the digital world and the physical world are connected, and the research of metasurfaces also steps into a new era of digitalization. However, the function switch of traditional programmable metamaterials cannot be achieved without human instruction and control. In order to achieve richer and more flexible function regulation and even higher level metasurface design, the intelligence of metamaterials is an important direction in its future development. In this paper, we review the development of tunable, programmable, and intelligent metasurfaces over the past 5 years, focusing on basic concepts, working principles, design methods, manufacturing, and experimental validation. Firstly, several manipulation modes of tunable metasurfaces are discussed; in particular, the metasurfaces based on temperature control, mechanical control, and electrical control are described in detail. It is demonstrated that the amplitude and phase responses can be flexibly manipulated by the tunable metasurfaces. Then, the concept, working principle, and design method of digital coding metasurfaces are briefly introduced. At the same time, we introduce the active programmable metasurfaces from the following aspects, such as structure, coding method, and three-dimensional far-field results, to show the excellent electromagnetic manipulation ability of programmable metasurfaces. Finally, the basic concepts and research status of intelligent metasurfaces are discussed in detail. Different from the previous programmable metamaterials, which must be controlled by human intervention, the new intelligent metamaterials control system will realize autonomous perception, autonomous decision-making, and even adaptive functional manipulation to a certain extent.
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Si, Wenrong, Chenzhao Fu, Fengyuan Gan, Dun Lan, and Wei Li. "Dynamic Beam Switching by the Highly Sensitive Metasurface Composed of All-Metallic Split-Ring Resonators." Journal of Nanomaterials 2022 (July 14, 2022): 1–6. http://dx.doi.org/10.1155/2022/5186069.
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The development of metasurfaces capable of arbitrarily manipulating electromagnetic waves has created new opportunities for various applications. However, most tunable metasurface devices via different modulation techniques exhibit large fabrication difficulties or narrow bandwidths. Here, we use the all-metallic split-ring resonator to design a dynamically tunable metasurface that is highly sensitive to the ambient refractive index and capable of broadband beam switching. Different from the previous optical scatters, the split-ring resonator is put on the metal substrate. Due to the existence of metallic substrate and large interaction of corner modes, the proposed resonator has small ohmic loss and high sensitivity to the ambient refractive index. By arraying the all-metallic split-ring resonators with different parameters, dynamic beam switching of anomalous reflection is demonstrated numerically. In particularly, the designed metasurface exhibits the dynamic beam switching in a broadband wavelength range of Δλ≈100 nm. Such an all-metallic metasurface with high sensitivity can greatly reduce the designing difficulty of the tunable optical devices. The dynamic metadevices may find potential applications in stealth camouflage, information encryption, and data storage.
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Zhang, Ming, Peng Dong, Yu Wang, et al. "Tunable Terahertz Wavefront Modulation Based on Phase Change Materials Embedded in Metasurface." Nanomaterials 12, no. 20 (2022): 3592. http://dx.doi.org/10.3390/nano12203592.
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In the past decades, metasurfaces have shown their extraordinary abilities on manipulating the wavefront of electromagnetic wave. Based on the ability, various kinds of metasurfaces are designed to realize new functional metadevices based on wavefront manipulations, such as anomalous beam steering, focus metalens, vortex beams generator, and holographic imaging. However, most of the previously proposed designs based on metasurfaces are fixed once design, which is limited for applications where light modulation needs to be tunable. In this paper, we proposed a design for THz tunable wavefront manipulation achieved by the combination of plasmonic metasurface and phase change materials (PCMs) in THz region. Here, we designed a metal-insulator-metal (MIM) metasurface with the typical C-shape split ring resonator (CSRR), whose polarization conversion efficiency is nearly 90% for circular polarized light (CPL) in the range of 0.95~1.15 THz when PCM is in the amorphous state, but the conversion efficiency turns to less than 10% in the same frequency range when PCM switches into the crystalline state. Then, benefiting from the high polarization conversion contrast of unit cell, we can achieve tunable wavefront manipulation by utilizing the Pancharatnam–Berry (PB) phase between the amorphous and crystalline states. As a proof-of-concept, the reflective tunable anomalous beam deflector and focusing metalens are designed and characterized, and the results further verify their capability for tunable wavefront manipulation in THz range. It is believed that the design in our work may pave the way toward the tunable wavefront manipulation of THz waves and is potential for dynamic tunable THz devices.
Dissertationen zum Thema "Tunable metasurface"
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del, Hougne Marc Philipp. "Shaping Green's Functions in Cavities with Tunable Boundary Conditions : From Fundamental Science to Applications." Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCC111.
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Cette thèse étudie le façonnage de champs électromagnétiques micro-ondes dans des cavités présentant des conditions aux limites reconfigurables. Le dispositif expérimental s'appuie sur une metasurface électroniquement reconfigurable qui couvre partialement les parois d'une cavité et qui permet ainsi de contrôler la façon dont les ondes y sont réfléchies. Le premier chapitre explore des aspects fondamentaux. D’abord, une étude paramétrique du façonnage d'un champ d'ondes électromagnétiques monochromatique et stationnaire en cavité est proposée en fonction d'un degré de contrôle introduit. Selon la valeur de ce paramètre, il est possible de concentrer de l'énergie en un endroit donné de la cavité de façon prédictible, de reconfigurer totalement cette cavité, ou bien de décider d'obtenir une résonance à une fréquence qui n'en supportait pas auparavant. Ensuite, l’imposition d’un comportement chaotique à une cavité de géométrie régulière est démontrée et une application au brassage des modes en chambre réverbérante est donnée. Dans la suite, la possibilité d’ajuster le couplage antenne-cavité est abordée, et une adaptation parfaite et dynamiquement configurable de l’impédance est proposée. Le reste du premier chapitre considère des champs transitoires. Dans un premier temps, la focalisation spatio-temporelle d’une impulsion fortement réverbérée dans une cavité en utilisant uniquement le contrôle spatial des ondes offert par la metasurface est démontrée, puis le lien avec le couplage entre les dégrées de liberté spatiaux et temporels du milieu de propagation est fait. Enfin, un dispositif permettant la reconfiguration répétée des conditions aux limites d'une cavité en un laps de temps inférieur au temps de vie des photons est réalisé, et des résultats préliminaires sont montrés. Dans le deuxième chapitre, des applications aux systèmes de communication sans fil multi-utilisateurs sont proposées. D’abord, dans la limite d’un bas facteur de qualité de la cavité, il est montré qu’un formalisme matriciel permet de décrire l’impact de la metasurface sur le champ. Cette matrice, mesurée sans information de phase, permet alors de focaliser le champ sur une ou plusieurs positions simultanément. Ensuite, la possibilité d’obtenir une diversité de canaux optimale (orthogonalité des canaux) en façonnant idéalement le désordre d’un milieu de propagation à l'aide de metasurfaces est établie. Finalement, le formalisme matriciel est utilisé afin d’introduire un concept de calcul analogique réalisé par le milieu désordonné en façonnant le front d’onde incident. Il est dès lors conclu qu’avec une infrastructure standard de Wi-Fi dans une maison, en combinaison avec une metasurface simple, cette idée peut être implémentée. Le concept est enfin transposé au domaine optique avec une fibre multimode. Au cours du troisième chapitre, quelques applications du façonnage d'ondes en milieux réverbérants aux capteurs des environnements connectés sont étudiées. D’abord, la possibilité de concentrer des champs électromagnétiques ambients sur des circuits redresseurs afin d’obtenir des tensions de sortie utiles est démontrée. De plus, grâce aux non-linéarités intrinsèques du redresseur, ceci est possible même sans avoir un retour direct du redresseur sur l’intensité du champ incident. Ensuite, un détecteur de mouvement hors ligne de vue et « intelligent » est proposé, qui profite d’un co-design de sa couche physique et du traitement de données. Enfin, il est démontré que même des objets non-coopératifs dans un environnement complexe peuvent être localisés grâce à leur contribution à la diffusion des ondes dans ledit milieu. L’équivalence d’utiliser la diversité fréquentielle ou bien le façonnage d’ondes dans ce contexte est établie<br>In this thesis, the shaping of microwave fields in chaotic cavities with tunable boundary conditions is studied experimentally. The experiments leverage a metasurface reflect-array that partially covers the cavity walls to tune the reverberation of waves inside the cavity. The first chapter explores several fundamental aspects. First, the achievable degree of control over stationary monochromatic wave fields is thoroughly investigated, and various regimes are identified, ranging from partial control over the wave field up to the limiting case of discrete resonances that can be tuned at wish. Next, the possibility to convert a cavity of regular geometry into one displaying chaotic characteristics by modulating the boundary conditions is examined and an application to non-mechanical mode-stirring in reverberation chambers is given. Then, the ability to tune the coupling between an antenna inside a cavity and the cavity itself is studied, revealing the opportunity of achieving (dynamically tunable) perfect impedance matching. The chapter goes on to consider spatio-temporal wave fields, and the re-focusing of such transient fields at a desired instant with the purely spatial control of the metasurface is demonstrated; moreover, the interplay of spatial and temporal degrees of freedom is addressed. Finally, an experimental platform enabling the rapid modulation of cavity boundary conditions within the photon lifetime is presented. The second chapter considers applications to multi-user wireless communication systems. First, it is shown that a matrix formalism to capture the impact of the metasurface on the wave field can be formulated in the regime of low reverberation, and even without access to phase information focusing on a single as well as on multiple targets is demonstrated. Second, it is shown that the channel diversity, which dominates the achievable capacity of information transfer, can be optimized by tweaking the environment’s disorder; perfectly orthogonal channels are obtained without any software or hardware efforts on the transmit or receive side, and the benefits of the implied minimal cross-talk are illustrated for the scenario of wirelessly transmitting a full-color image. Third, the matrix formalism is leveraged to propose a scheme of analog computation that counter-intuitively uses a disordered instead of a carefully tailored propagation medium, by appropriately shaping the incident wave front. A proof-of-concept demonstration suggests that combining ubiquitous Wi-Fi hardware in an indoor environment with a simple metasurface is sufficient to implement the concept. Finally, the concept is also implemented in the optical domain using a multimode fiber. The third chapter outlines a few applications for sensors in context-aware environments. First, it is shown that by shaping ambient wave fields, they may be concentrated on harvesting devices to increase the output voltage available for sensor powering; moreover, the non-linear nature of the harvesting device enables to do so without direct feedback from the target, using indirect feedback from the second harmonic. Second, a smart around-the-corner motion detector for complex environments is presented, enjoying a co-design of hardware and processing software by using a dynamic metasurface aperture; the latter is essentially a small (but still electrically large) disordered cavity with tunable boundaries that leaks tunable random radiation patterns that couple differently to the environment’s modes. Third, it is shown that objects may be precisely localized in complex environments even if they are non-cooperative by establishing signatures of their location that leverage their scattering contribution; this is demonstrated both with a frequency diverse and a wavefront shaping scheme, and the equivalence of the respective degrees of freedom is established
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Kepič, Peter. "Návrh a výroba laditelných dielektrických metapovrchů pro viditelné a infračervené vlnové délky." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-443746.
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Metapovrchy sú nanoštruktúrované povrchy vytvorené za účelom špecifického ovládania propagácie svetla. Predstavujú revolúciu v oblastiach ultratenkých optických prvkov a nanofotonických obvodov. Zakomponovaním laditeľných dielektrických materiálov do metapovrchov sa otvára možnosť aktívne ovládať ich optické vlastnosti aj po tom, čo boli vyrobené. Oxid vanadičitý (VO2) takéto ladenie umožňuje vďaka svojej fázovej premene už pri teplote okolo 67°C a preto sa radí k najsľubnejším z laditeľných dielektrických materiálov. Nakoľko je možné postupnú fázovú premenu vo VO2 vybudiť opticky a lúč svetla je možné fokusovať do stopy s veľkosťou pár stoviek nanometrov, laditeľné metapovrchy obsahujúce VO2 by mohli byť ladené postupne a dokonca s nanometrovým rozlíšením. V tejto práci skúmame fázu a amplitúdu svetla po prechode VO2 nanoštruktúrami usporiadanými do metapovrchu navrhnutého pre viditeľnú zložku elektromagnetického žiarenia. Výskum fáze a amplitúdy je založený na numerických simuláciách VO2 nanoštruktúr (stavebných kameňov metapovrchov), ktoré sú následne overené experimentálnymi výsledkami. VO2 nanoštruktúry vykazujú taktiež Mieho dielektrické rezonancie, ktoré sú v závere tejto práce využité v postupne laditeľnom metapovrchu fungujúcom vo viditeľnej oblasti. Okrem termálneho ladenia je možné vyrobený metapovrch ovládať taktiež opticky, čo dokazuje možnosť postupného ladenia na nanometrových rozmeroch.
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Huang, Yao-Wei, and 黃耀緯. "Plasmonic Metasurface for Visible Hologram and Electrically Tunable Devices." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/99763564084960663950.
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博士<br>國立臺灣大學<br>應用物理所<br>103<br>Nowadays, vision technologies in various color applications are primarily targeting the three primary colors and their mixing in conjunction with control of light polarization. The scalar diffractive pattern of liquid crystal displays (LCD) or digital micro-mirror devices (DMD) employed in hologram renders polarization unswitchable. The metamaterials or metasurfaces employed surface electromagnetic wave are capable of shaping both amplitude phase and polarization of light over subwavelength length scales. They have been previously applied to broadband and broad-angle phase hologram with polarization-dependent images but failed to yield color multiplexing in the visible spectrum.
In contrast, light information can be manipulated either in amplitude, phase, polarization, or frequency, and combination thereof. Chip based hybrid-plasmonic modulators made of incorporating nanoscale plasmonics and classic photonic elements has the fasted modulation speed and lowest energy-per-signal are proposed to overcome a limited propagation length and higher loss of a surface plasmon-polariton (SPP) mode. Metasurfaces composed of sub-wavelength artificial structures show promise for extraordinary light-manipulation and development of ultrathin optical components over a broad range of the electromagnetic spectrum. However structures developed to date do not allow for post-fabrication control of antenna properties. Metasurfaces incorporating dynamically tunable methods offer the unprecedented opportunities in reconfigurable flat optical devices.
In this dissertation, a phase modulated multi-color meta-hologram (MCMH) and an electrically gate-tunable metasurface were design and investigated. The MCMH made of sandwich structure of Al-nanorod/SiO2/Al-mirror arranged in a two-dimensional array of pixels is polarization-dependent and capable of producing images in three primary colors. With proper design of the structure, we obtain resonances of narrow bandwidths to allow for implementation of the multi-color scheme. Experimental reflected spectrum for each kind of nanorods array are investigated, which is in agreement with the simulation results and certainly lead to full color applications using color mixing.
We have investigated the integration of the transparent conductor indium tin oxide (ITO) active elements to realize gate-tunable phased arrays of subwavelength antenna in a reflectarray metasurface configuration to enable gate-tunable permittivity. The magnetic dipole resonance of each antenna interacts with the carrier density-dependent permittivity resonance of the ITO to enable phase and amplitude tunability. A multiphysics method incorporated semiconductor physics and electromagnetic waves are considered in the design and resonance analysis. A simple 2-level dynamic phase grating is investigated using the gate-tunable metasurface. With different applied biases, the controllable diffraction patterns have been investigated by dynamic phase grating system. This work provides a general design principle applicable to dynamic metasurface devices based on gate-tunable field effect.
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Lin, Meng-Ying, and 林孟穎. "Tunable optical Tamm states with metasurface-based half-wave plate." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/35dc5a.
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碩士<br>國立交通大學<br>影像與生醫光電研究所<br>105<br>Optical Tamm state is a localized surface mode that plamonic resonance occurred at the boundary between a photonic crystal and metal. We demonstrate, both simulation and experiment, the first observation of
optical Tamm state formed by cholesteric liquid crystal (CLC) and reflected metasurface. Conventional optical Tamm states have been investigated at the interface of distributed Bragg reflector (DBR) and metal. By varying the thickness of the top layer of DBR or making DBR porous, it could possibly tune the resonance wavelengths. However, it is very difficult to control the quality or modify the thickness of DBR after a sample is fabricated. Therefore, photonic liquid crystal called CLC is proposed to substitute the DBR to achieve the tunability of the resonance wavelength of the optical Tamm state, but the surface state cannot be excited directly with a photonic liquid crystal and flat metal films. The novel design of metasurfaces as reflective half-wave plates provides phase and polarization matching. At the interface between a photonic liquid crystal and a metasurface, a strong localized electric field and sharp resonance are observed. In this work, the spin selective optical Tamm
states has been accomplished. The resonance wavelength of optical Tamm states can be controlled by varying the temperature of the liquid crystal to achieve wide-range tunability.
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Komar, Andrei. "Tunable All-dielectric Metasurfaces: Fundamentals and Applications." Phd thesis, 2018. http://hdl.handle.net/1885/171649.
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All-dielectric metasurfaces have received significant attention
in the past years, and have been established as a platform for
efficient manipulation of optical beams. Advances in the design
and fabrication of such dielectric metasurfaces have led to the
development of several ultra-thin optical metadevices, including
flat lenses, beam converters, deflectors and holograms. Composed
of periodic or aperiodic lattices of dielectric nanoparticles,
metasurfaces exhibit low absorption in the infrared and visible
spectral ranges. Low losses allow nanoparticles to exhibit
Mie-type resonances with a higher quality-factor in comparison to
their plasmonic counterparts. Furthermore, Mie-type resonances in
dielectric nanoparticles offer two independent families of
resonant modes - electric and magnetic. The far-field
interference of these two types of resonant modes leads to
fundamentally new effects, such as unidirectional scattering,
unconventional reflection behaviour associated with the
generalised Brewster effect and near-unity transmission in the
so-called Huygens' regime. Operating in the Huygens' regime of
the dielectric metasurfaces enables the combination of near-unity
transmission together with a full range of phase modulation, thus
being the key to enabling functional dielectric metasurfaces with
nearly 100% efficiency.
Most functional dielectric metasurfaces to date are based on
static designs, defined through geometrical parameters, such as
nanoparticle shape, size, and array layout. However, in many
applications, it is crucial to enable dynamic tunability of the
device functionality with time. For example, the focal distance
of a camera lens needs to be changed when taking pictures of
objects at different distances; the position of the ranging beam
in a LIDAR (light imaging, detection, and ranging) for driverless
vehicles needs to scan different directions. Therefore,
implementing dynamic control} over the response of the
metasurfaces is of paramount importance for their practical
implementation.
In this thesis, I discuss possible ways to achieve tunability
from dielectric metasurfaces. At first, I consider existing
methods, their pros and cons, as well as possible applications.
Further, I offer several methods that I developed and
investigated, both theoretically and experimentally. Namely, I
describe tuning by changing the properties of resonator material,
where I utilise a thermo-optic effect to control the refractive
index of resonator particles and consequently the optical
response of metasurfaces. Next, I consider tuning by changing the
properties of surrounding material, first theoretically, and
later demonstrating experimental realisation of this concept
using a liquid crystal as a tuning medium. Finally, I describe
two tunable metadevices: one, for switching a beam deflection,
and second, for active tuning of spontaneous emission.
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Lee, Jongwon. "Nonlinear and wavelength-tunable plasmonic metasurfaces and devices." Thesis, 2014. http://hdl.handle.net/2152/28053.
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Wavelength-tunable optical response from solid-state optoelectronic devices is a desired feature for a variety of applications such as spectroscopy, laser emission tuning, and telecommunications. Nonlinear optical response, on the other hand, has an important role in modern photonic functionalities, including efficient frequency conversions, all-optical signal processing, and ultrafast switching. This study presents the development of optical devices with wavelength tunable or nonlinear optical functionality based on plasmonic effects. For the first part of this study, widely wavelength tunable optical bandpass filters based on the unique properties of long-range surface plasmon polaritons (LR SPP) are presented. Planar metal stripe waveguides surrounded by two different cladding layers that have dissimilar refractive index dispersions were used to develop a wide wavelength tuning. The concept was demonstrated using a set of index-matching fluids and over 200nm of wavelength tuning was achieved with only 0.004 of index variation. For practical application of the proposed concept, a thermo-optic polymer was used to develop a widely tunable thermo-optic bandpass filter and over 220 nm of wavelength tuning was achieved with only 8 ºC of temperature variation. Another novel approach to produce a widely wavelength tunable optical response for free-space optical applications involves integrating plasmonic metasurfaces with quantum-electronic engineered semiconductor layers for giant electro-optic effect, which is proposed and experimentally demonstrated in the second part of this study. Coupling of surface plasmon modes formed by plasmonic nanoresonators with Stark tunable intersubband transitions in multi-quantum well structures induced by applying bias voltages through the semiconductor layer was used to develop tunable spectral responses in the mid-infrared range. Experimentally, over 310 nm of spectral peak tuning around 7 μm of wavelength with 10 ns response time was achieved. As the final part of this study, highly nonlinear metasurfaces based on coupling of electromagnetically engineered plasmonic nanoresonators with quantum-engineered intersubband nonlinearities are proposed and experimentally demonstrated. In the proof-of-concept demonstration, an effective nonlinear susceptibility over 50 nm/V was measured and, after further optimization, over 480 nm/V was measured for second harmonic generation under normal incidence. The proposed concept shows that it is possible to engineer virtually any element of the nonlinear susceptibility tensor of the nonlinear metasurface.<br>text
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Zou, Chengjun. "Optical metasurfaces based on nano-scale dielectric resonators." Thesis, 2017. http://hdl.handle.net/2440/107379.
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This thesis summarises my PhD research towards applying nano-scale dielectric resonators (DRs) to optical metasurfaces for achieving various functionalities, high efficiency, and reconfigurability. Additionally, the thesis also provides brief introductions to dielectric resonator antennas, plasmonics, and a short review of optical metasurfaces. The major contributions are briefly summarised as follows:
In Chapter 3, resonance properties of cylindrical nano-scale DRs on metallic substrates are analysed. At optical frequencies, subwavelength DRs with metallic substrates can support horizontal magnetic dipole resonance, which can be used for efficient coupling of surface plasmons. However, two types of resonance breakdown can occur in such DRs, and the cause for both types are analysed in detail. Of particular interest is the negatively-matched resonance breakdown, which occurs when real parts of the permittivities of a DR and its metallic substrate are negatively matched. The negatively-matched resonance breakdown is undesired for optical metasurfaces and can be avoided by inserting a low-permittivity dielectric spacer between the DR and its metallic substrate. In Chapter 4, unidirectional launching of surface plasmons based on non-uniform arrays of DRs is proposed and investigated. By comparing the principles of DR-based anomalous reflection and surface plasmon unidirectional launching, it is concluded that the optimal launching can be achieved by avoiding the first-order diffraction. The optimal launching condition is verified with numerical simulations and linear array theory. In Chapter 5, a narrowband plasmonic absorber made of a uniform array of nano-scale DRs on metallic substrates is experimentally demonstrated at visible frequencies. It relies on the surface plasmon standing waves coupled by the locally resonant nano-scale DRs for the high absorption. The simulation and measurement results are presented and analysed with coupled mode theory. In Chapter 6, a mechanically tunable DR metasurface is experimentally demonstrated at visible frequencies. The tunable metasurface is realised by embedding a uniform array of DRs into an elastomeric encapsulation. The transmission responses of the metasurface can be tuned when the encapsulation is deformed with an external strain. Measurement results confirm the predictions of simulations and shows a remarkable tuning range. A Lagrangian model is developed to rigorously analyse the simulation and measurement results. Such a design provides a preliminary concept usable in reconfigurable optical devices, and after further development can also be potentially commercialised for smart contact lenses. In Chapter 7, metasurfaces made of metal-loaded DR arrays are proposed to realise the functionality of selective thermal emission. Two metasurface designs are presented. The first design is based on a uniform array of square metal-loaded DRs, which are made of doped silicon. Theoretical and numerical analysis demonstrate stable emission peaking at nearly 8 μm across a wide temperature range. The second further-developed thermal emission metasurface is designed to have broadband emission from 8 to 13 μm atmosphere window range and low emission at all other wavelengths. In this way, it can realise the function of radiative cooling. These studies along with corresponding simulations or experimental validations demonstrate various functionalities can be realised with DR metasurfaces at optical frequencies. Furthermore, these nanostructure designs suggest a promising route for achieving the next generation highly-efficient integrated optical systems based on nano-scale DRs.<br>Thesis (Ph.D.) -- University of Adelaide, School of Electrical and Electronic Engineering, 2017.
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Kafaie, Shirmanesh Ghazaleh. "Electro-Optically Tunable Metasurfaces for a Comprehensive Control of Properties of Light." Thesis, 2020. https://thesis.library.caltech.edu/13955/7/Thesis_Ghazaleh_Kafaie_Shirmanesh_09_16_2020.pdf.
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<p>The ability to control electromagnetic wavefront is a central key in optics. Conventional optical components rely on the gradual accumulation of the phase of light as it passes through an optical medium. However, since the accumulated phase is limited by the permittivity of naturally existing materials, such a mechanism often results in bulky devices that are much thicker than the operating wavelength.</p>
<p>During the last several years, metasurfaces (quasi-2D nanophotonic structures) have attracted a great deal of attention owing to their promise to manipulate constitutive properties of electromagnetic waves such as amplitude, phase, and polarization. Metasurfaces are ultrathin arrays of subwavelength resonators, called meta-atoms, where each meta-atom imposes a predefined change on the properties of the scattered light. By precisely designing the optical response of these meta-atoms to an incident wave, metasurfaces can introduce abrupt changes to the properties of the transmitted, reflected, or scattered light, and hence, can flexibly shape the out-going wavefront at a subwavelength scale. This enables metasurfaces to replace conventional bulky optical components such as prisms or lenses by their flat, low-profile analogs. Furthermore, a single metasurface can perform optical functions typically attained by using a combination of multiple bulky optical elements, offering tremendous opportunities for flat optics.</p>
<p>The optical response of a metasurface is typically dictated by the geometrical parameters of the subwavelength scatterers. As a result, most of the reported metasurfaces have been passive, namely have functions that are entirely fixed at the time of fabrication. By making the metasurfaces reconfigurable in their phase, amplitude, and polarization response, one can achieve real-time control of optical functions, and indeed, achieve multi-functional characteristics after fabrication. Dynamical control of the properties of the scattered light is possible by using external stimuli such as electrical biasing, optical pumping, heating, or elastic strain that can give rise to changes in the dielectric function or physical dimensions of the metasurface elements.</p>
<p>In this dissertation, we present the opportunities and challenges towards achieving reconfigurable metasurfaces. We introduce a paradigm of active metasurfaces for real-time control of the wavefront of light at a subwavelength scale by investigating different modulation mechanisms and possible metasurface designs and material platforms that let us effectively employ the desired modulation mechanism. We will present multiple electro-optically tunable metasurface platforms. These electronically-tunable schemes are of great interest owing to their robustness, high energy-efficiency, and reproducibility. We will also show the design and experimental demonstration of active metasurfaces for which the tunable optical response can be tailored in a pixel-by-pixel configuration.</p>
<p>The ability to individually control the optical response of metasurface elements has made active optical metasurfaces to be progressively ubiquitous by enabling a wide range of optical functions such as dynamic holography, light fidelity (Li-Fi), focusing, and beam steering. As a result, reconfigurable metasurfaces can hold an extraordinary promise for optical component miniaturization and on-chip photonic integration. Such compact and high-performance devices with reduced size, weight, and power (SWaP) can be used in future free-space optical communications or light detection and ranging (LiDAR) systems.</p>
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Hsu, Yao-Yu, and 許曜宇. "In situ circular dichroism tunable and switchable chiral metasurfaces on flexible PDMS substrate." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/353kqj.
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碩士<br>國立交通大學<br>光電工程研究所<br>107<br>The metasurfaces are refers to the metamaterials with sub-wavelength thickness, which are artificial structure produce electromagnetic phenomena not normally found in nature. When an un-polarized light pass through two asymmetry metasurface, it will produce a corresponding left-handed or right-handed circular polarization. And these two asymmetry metasurface are enantiomer to each other. In this thesis, we combine two enantiomer dimers to form a symmetrical metasurface, and then control the circular dichroism by breaking symmetric with stretch. The original designed metasurface will not cause circular dichroism when non-polarized light normal incident the device. However, when the flexible substrates sustain a strain, the relative position of the gold nanorods will change, leads to symmetry breaking and the metasurface will generate a relative circular dichroism. This is because when one of enantiomer dimer is decoupled, the circular dichroism spectra will dominate by another. Moreover, since the symmetry has been broken, the relative circular dichroism is generated.
In this work, the flexible metasurfaces was fabricated by using e-beam lithography, electron beam evaporation and PDMS bonding process. Its ability of tuning and switching circular dichroism in near Infrared and visible light region has been proved by Proof-of-Concept and further demonstrated in real device. Furthermore, the elements of STNR are also investigated by extinction spectra. This work can further use in several applications in the future, such as chemical and biochemical sensing, drug analysis, chiral light source.
Bücher zum Thema "Tunable metasurface"
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Zhu, Weiming, and Ai-Qun Liu. Metasurfaces: Towards Tunable and Reconfigurable Meta-devices. Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-6925-6.
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Liu, Ai-Qun, and Weiming Zhu. Metasurfaces: Towards Tunable and Reconfigurable Meta-Devices. Springer, 2023.
Den vollen Inhalt der Quelle findenBuchteile zum Thema "Tunable metasurface"
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Zhu, Weiming, and Ai-Qun Liu. "Tunable Chiral Metasurfaces." In Metasurfaces: Towards Tunable and Reconfigurable Meta-devices. Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-6925-6_6.
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Zhu, Weiming, and Ai-Qun Liu. "MEMS Metasurfaces." In Metasurfaces: Towards Tunable and Reconfigurable Meta-devices. Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-6925-6_2.
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Zhu, Weiming, and Ai-Qun Liu. "Microfluidic Metasurfaces." In Metasurfaces: Towards Tunable and Reconfigurable Meta-devices. Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-6925-6_3.
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Zhu, Weiming, and Ai-Qun Liu. "Introduction of Metasurfaces." In Metasurfaces: Towards Tunable and Reconfigurable Meta-devices. Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-6925-6_1.
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Zhu, Weiming, and Ai-Qun Liu. "Adaptive Metasurfaces for Dispersion Control." In Metasurfaces: Towards Tunable and Reconfigurable Meta-devices. Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-6925-6_8.
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Zhu, Weiming, and Ai-Qun Liu. "Reconfigurable Metasurfaces for Dynamic Polarization Control." In Metasurfaces: Towards Tunable and Reconfigurable Meta-devices. Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-6925-6_9.
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Zhu, Weiming, and Ai-Qun Liu. "Tunable Optical Anisotropic Metasurfaces with Dynamic Control of In-Plane Symmetry." In Metasurfaces: Towards Tunable and Reconfigurable Meta-devices. Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-6925-6_5.
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Zhu, Weiming, and Ai-Qun Liu. "Tunable Absorber Based on Meta-fluidic-Materials." In Metasurfaces: Towards Tunable and Reconfigurable Meta-devices. Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-6925-6_7.
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Zhu, Weiming, and Ai-Qun Liu. "Tunable and Reconfigurable Flat Optics: An Outlook." In Metasurfaces: Towards Tunable and Reconfigurable Meta-devices. Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-6925-6_10.
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Zhu, Weiming, and Ai-Qun Liu. "Tunable Electromagnetic Resonances with Slab-Split-Ring Meta-molecules." In Metasurfaces: Towards Tunable and Reconfigurable Meta-devices. Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-6925-6_4.
Der volle Inhalt der QuelleKonferenzberichte zum Thema "Tunable metasurface"
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Li, Weijian, and Gururaj V. Naik. "1T-TaS2 based dynamically tunable plasmonic metasurface." In CLEO: QELS_Fundamental Science. Optica Publishing Group, 2022. http://dx.doi.org/10.1364/cleo_qels.2022.fth2d.3.
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We demonstrate a dynamically tunable plasmonic metasurface enabled by light-tunable optical constants of a quantum material - 1T-TaS2. We observe a relative reflectance change of 10% under low-intensity incoherent illumination.
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Park, Junghyun, Byung Gil Jeong, Sun Il Kim, et al. "Electrically tunable metasurface for lidar." In Plasmonics: Design, Materials, Fabrication, Characterization, and Applications XVIII, edited by Takuo Tanaka and Din Ping Tsai. SPIE, 2020. http://dx.doi.org/10.1117/12.2567084.
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Arbabi, Ehsan, Amir Arbabi, Seyedeh Mahsa Kamali, Yu Horie, MohammadSadegh Faraji-Dana, and Andrei Faraon. "MEMS-tunable dielectric metasurface lens." In CLEO: Science and Innovations. OSA, 2018. http://dx.doi.org/10.1364/cleo_si.2018.sf1j.2.
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Xu, Hong Xin, Yan Rui Chen, Yong Jin Zhou, and Shi Yi Xiao. "Dynamically Tunable Electromagnetic Stealth Metasurface." In 2022 Photonics & Electromagnetics Research Symposium (PIERS). IEEE, 2022. http://dx.doi.org/10.1109/piers55526.2022.9793060.
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Haque, Ahasanul, Monir Morshed, Ahmmed A. Rifat, et al. "Electrically Tunable MnO2 Based Metasurface." In 2018 IEEE Photonics Conference (IPC). IEEE, 2018. http://dx.doi.org/10.1109/ipcon.2018.8527335.
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Kapitanova, Polina, Mikhail Odit, Dmitry Dobrykh, Andrei Andryieuski, Andrei V. Lavrinenko, and Pavel Belov. "Tunable water-based microwave metasurface." In 2017 11th European Conference on Antennas and Propagation (EUCAP). IEEE, 2017. http://dx.doi.org/10.23919/eucap.2017.7928190.
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Foo, Senglee. "Liquid-crystal-tunable metasurface antennas." In 2017 11th European Conference on Antennas and Propagation (EUCAP). IEEE, 2017. http://dx.doi.org/10.23919/eucap.2017.7928122.
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Tian, Haozhan, Mohammad Memarian, and Tatsuo Itoh. "Electronically-tunable resonant blazed metasurface grating." In 2017 IEEE Asia Pacific Microwave Conference (APMC). IEEE, 2017. http://dx.doi.org/10.1109/apmc.2017.8251458.
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She, Alan, Shuyan Zhang, Samuel Shian, David Clarke, and Federico Capasso. "Large Area Electrically Tunable Metasurface Lenses." In CLEO: QELS_Fundamental Science. OSA, 2017. http://dx.doi.org/10.1364/cleo_qels.2017.ftu3g.4.
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Weiss, Aharon, Christian Frydendahl, Jonathan Bar-David, et al. "Tunable Metasurface using thin film lithium-niobate in the telecom regime." In CLEO: QELS_Fundamental Science. Optica Publishing Group, 2022. http://dx.doi.org/10.1364/cleo_qels.2022.fm5f.3.
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We demonstrate a tunable metasurface made of aluminum nanodisk array coated with ITO on a thin film of lithium niobate. A spectral resonant shift of few nanometers and modulation contrast of ~40% are observed.