Review
Nanoscience & Nanotechnology
Hammad Ahmed, Hongyoon Kim, Yuebian Zhang, Yuttana Intaravanne, Jaehyuck Jang, Junsuk Rho, Shuqi Chen, Xianzhong Chen
Summary: This article reviews the recent progress in optical metasurface-based optical vortices (OVs), with a comprehensive discussion on the optical manipulation of OVs, including OAM superposition, OAM sorting, OAM multiplexing, OAM holography, and nonlinear metasurfaces. The rapid development of metasurfaces for OVs generation and manipulation will play an important role in relevant research fields.
Article
Chemistry, Multidisciplinary
Jian Zhang, Qiang Li, Chenjie Dai, Mingliang Cheng, Xin Hu, Hyun-Sik Kim, Heesun Yang, Daniel J. Preston, Zhongyang Li, Xuefeng Zhang, Won-Kyu Lee
Summary: This paper presents a general approach to developing tunable plasmonic metasurfaces with hydrogel meta-atoms at the subwavelength scale. The size of hydrogel nanodots can be reversibly controlled by absorbing or releasing water, resulting in humidity-responsive surface plasmon polaritons (SPPs) that generate plasmonic color rendering in the visible spectrum. The size variations of constituent hydrogel nanostructures enable broadband beam-steering on a phase modulator.
Article
Multidisciplinary Sciences
Sukhvinder Kaur, Subhajit Karmakar, Arun Jana, Shreeya Rane, Ravendra Kumar Varshney, Dibakar Roy Chowdhury
Summary: The control and manipulation of cavity resonances can be achieved through modifying the split ring resonator geometry in hybrid plasmonic metasurface, leading to the excitation of dual resonance peaks with high quality factor and multi-band resonances.
Article
Optics
Mahmoud Elsawy, Christina Kyrou, Elena Mikheeva, Remi Colom, Jean-Yves Duboz, Khosro Zangeneh Kamali, Stephane Lanteri, Dragomir Neshev, Patrice Genevet
Summary: Optical metasurfaces with nearly 100% efficiency for full phase modulation have been achieved through an innovative design strategy based on the position of topological singularities. Active metasurface unit cells consisting of asymmetric Gires-Tournois resonators filled with silicon or hetero-structured materials have been utilized to leverage on thermo-optical or electro-optical effects. Optimization of the refractive index modulation profile in the extended unit cell has improved deflection efficiencies for each deflection angle, reaching above 90% for active thermo-optical effect and nearly 92% for active wavefront splitting. These highly efficient active beam forming designs have significant applications in imaging microscopy and 3D light detection and ranging (LiDAR).
LASER & PHOTONICS REVIEWS
(2023)
Article
Optics
Anna Fedotova, Mohammadreza Younesi, Maximilian Weissflog, Dennis Arslan, Thomas Pertsch, Isabelle Staude, Frank Setzpfandt
Summary: Spatial engineering of the nonlinear susceptibility & chi;(2) in resonant metasurfaces through electric field poling of lithium niobate (LN) thin films provides a new degree of freedom in the design of far-field second-harmonic generation (SHG) response. Metasurfaces fabricated in periodically poled LN films reveal the significant influence of & chi;(2) patterning on the spatial distribution of the second harmonic. This work represents a first step towards far-field engineering of SHG in metasurfaces with electric field poling.
PHOTONICS RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Wu Zhang, Haizeng Li, Abdulhakem Y. Elezzabi
Summary: This study presents the manipulation of silver adatoms for aqueous plasmonic electrochromic devices through underpotential deposition. It is found that underpotential deposition of silver nanoparticles enables reversible voltage-activated dynamic plasmonic color change and size control of the grown nanoparticles.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Physics, Multidisciplinary
Zhiqiang Du, Zhengyong Song
Summary: Due to the increasing complexity of modern communication systems, the requirements for electromagnetic wave are becoming more and more rigorous. Metasurfaces based on Ge3Sb2Te6 are designed to control electromagnetic wavefront in the mid-infrared range by changing the state of Ge3Sb2Te6. By designing specific structures, deflection of electromagnetic wavefront and vortex beams with orbital angular momentum can be achieved. This design may lead to novel types of metasurfaces.
Article
Multidisciplinary Sciences
Wei Ting Chen, Joon-Suh Park, Justin Marchioni, Sophia Millay, Kerolos M. A. Yousef, Federico Capasso
Summary: The authors present a dispersion-engineered set of eight nanostructures that can provide 0 to 2pi full-phase coverage. Their design achieves a broadband and polarization-insensitive 90% relative diffraction efficiency from 450 nm to 700 nm. By applying dispersion engineering, they demonstrate a set of nanostructures with nearly identical dispersion properties, enabling improved relative diffraction efficiency for metasurface components such as metalenses.
NATURE COMMUNICATIONS
(2023)
Article
Optics
Ruixing Nie, Canhui He, Runxuan Zhang, Zhengyong Song
Summary: Reflective meta-atoms based on vanadium dioxide (VO2) are designed to achieve wavefront reconfiguration in terahertz frequency. The meta-atoms provide full phase coverage and high polarization conversion efficiency when VO2 is in the metal state. However, when VO2 undergoes phase transition to the insulating state, the phase coverage and polarization conversion capability decrease significantly. Three metasurfaces, including anomalous reflector, met-alens, and vortex beam generator, demonstrate wavefront manipulation and polarization conversion abilities when VO2 is in the metal state. On the other hand, when VO2 is in the insulating state, the metasurfaces function as specular reflectors. Simulations verify the wavefront modulation and polarization control abilities of the proposed metasurfaces.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Ruoxu Wang, Fei Han, Bo Chen, Lingmei Liu, Shaoyan Wang, Hua Zhang, Yu Han, Hongyu Chen
Summary: By manipulating the nucleation and growth of solid materials, a general strategy has been presented to synthesize and manipulate nanoscale liquid droplets. Liquid nanoparticles have great potential in various applications and can be manipulated like their solid counterparts.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Xiaolong Zhu, Jacob Engelberg, Sergei Remennik, Binbin Zhou, Jonas Nyvold Pedersen, Peter Uhd Jepsen, Uriel Levy, Anders Kristensen
Summary: This work presents a cost-effective and lithography-free method for printing optical metasurfaces. By utilizing resonant absorption of laser light in an optical cavity formed by a multilayer structure, nearly perfect light absorption is achieved through interferometric control. This approach demonstrates reliability, upscaling, and subwavelength resolution in creating metasurfaces for structural colors, optical holograms, and diffractive optical elements.
Review
Chemistry, Multidisciplinary
Cheng-Wei Qiu, Tan Zhang, Guangwei Hu, Yuri Kivshar
Summary: The full manipulation of electromagnetic waves through optical metasurfaces is at the forefront of modern optical technologies. Future developments include hybrid metasurfaces using low-dimensional materials and their applications in biomedical, computational, and quantum fields. Challenges and opportunities in the future of metasurface physics and engineering are also discussed.
Review
Medicine, Research & Experimental
Ziqing Wu, Hao Zhang, Jing Yan, Yan Wei, Jiacan Su
Summary: Biological membrane engineering methods can enhance the functionality of biomembrane-derived nanoparticles for improved drug delivery and treatment. These methods can be applied to various biomembranes and are expected to play a significant role in the treatment and diagnosis of cancer, inflammation, immunological diseases, bone diseases, and Alzheimer's disease.
Article
Multidisciplinary Sciences
Soon Wei Daniel Lim, Joon-Suh Park, Dmitry Kazakov, Christina M. Spaegele, Ahmed H. Dorrah, Maryna L. Meretska, Federico Capasso
Summary: This research achieves the precise positioning of phase singularities using wavefront-shaping devices and metasurface technology, providing simplified and miniaturized solutions for applications such as optical traps and super-resolution microscopes.
NATURE COMMUNICATIONS
(2023)
Article
Optics
Thomas Pertsch, Shumin Xiao, Arka Majumdar, Guixin LI
Summary: Optical metasurfaces are a crucial area of research worldwide due to their potential applications in imaging, wavefront engineering, nonlinear optics, and quantum information processing. The feature issue "Optical Metasurfaces: Fundamentals and Applications in Photonics Research" aims to publish and disseminate the latest works in optical metasurfaces among the photonics community.
PHOTONICS RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Nikita Nefedkin, Ahmed Mekawy, Jonas Krakofsky, Yongrui Wang, Alexey Belyanin, Mikhail Belkin, Andrea Alu
Summary: Engineered intersubband transitions in multi-quantum well semiconductor heterostructures exhibit high second-order nonlinear susceptibilities in metasurfaces. By optimizing the design, the saturation limits in mid-infrared frequency upconversion in nonlinear metasurfaces are significantly extended. This has important implications for night-vision imaging and compact nonlinear wave mixing systems.
ADVANCED MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Y. Ra'di, A. Alu
Summary: In this paper, the authors review the physical mechanisms, functionalities, and recent progress of metagratings. Conventional gradient metasurfaces have limitations in rerouting impinging waves with overall efficiency, especially for extreme wavefront transformations. However, metagratings can manipulate light with unitary efficiency even in extreme conditions and offer advantages such as simpler fabrication and broader bandwidths.
IEEE PHOTONICS JOURNAL
(2022)
Article
Optics
Marco Piccardo, Vincent Ginis, Andrew Forbes, Simon Mahler, Asher A. Friesem, Nir Davidson, Haoran Ren, Ahmed H. Dorrah, Federico Capasso, Firehun T. Dullo, Balpreet S. Ahluwalia, Antonio Ambrosio, Sylvain Gigan, Nicolas Treps, Markus Hiekkamaki, Robert Fickler, Michael Kues, David Moss, Roberto Morandotti, Johann Riemensberger, Tobias J. Kippenberg, Jerome Faist, Giacomo Scalari, Nathalie Picque, Theodor W. Haensch, Giulio Cerullo, Cristian Manzoni, Luigi A. Lugiato, Massimo Brambilla, Lorenzo Columbo, Alessandra Gatti, Franco Prati, Abbas Shiri, Ayman F. Abouraddy, Andrea Alu, Emanuele Galiffi, J. B. Pendry, Paloma A. Huidobro
Summary: Our ability to manipulate light patterns by combining different electromagnetic modes has significantly improved in recent years. This concept of structured light is being applied across various fields of optics, enabling the generation of classical and quantum states of light, utilization of linear and nonlinear light-matter interactions, and advancements in microscopy, spectroscopy, holography, communication, and synchronization. This Roadmap provides an overview of these areas, their current research, and future developments, emphasizing the power of multimodal light manipulation to inspire new approaches in this vibrant research community.
Article
Acoustics
Yu-Gui Peng, Yarden Mazor, Andrea Alu
Summary: The cross-coupling between strain and velocity in acoustic materials, known as Willis coupling, has gained increasing attention in acoustics. Willis coupling provides a new degree of freedom for controlling sound propagation and has enabled novel applications. This study explores the constraints and wave features in Willis media based on constitutive relations and the acoustic Poynting theorem. Additionally, a nonlocal model is proposed to uncover the relation between Willis media and nonlocal materials.
Article
Multidisciplinary Sciences
Robert Duggan, Hady Moussa, Younes Ra'di, Dimitrios L. Sounas, Andrea Alu
Summary: Active materials have been investigated to achieve superluminal group velocities, but causality imposes a trade-off between bandwidth, velocity, and propagation distance. This study establishes a bound on these quantities based on stability considerations, which is applicable to causal structures of any complexity. The results reveal that only minor improvements in superluminal bandwidth can be practically achieved with increasing system complexity. These findings provide important physical insights into the limitations of superluminal structures and their implications for various technologies.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Ming Kang, Ziying Zhang, Tong Wu, Xueqian Zhang, Quan Xu, Alex Krasnok, Jiaguang Han, Andrea Alu
Summary: This study combines coherent control of wave phenomena and the physics of bound states in the continuum, achieving extreme control over light polarization spanning the entire Poincare sphere. The findings open up new opportunities for photonics and quantum optics applications.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Tan Shi, Zi-Lan Deng, Guangzhou Geng, Xianzhi Zeng, Yixuan Zeng, Guangwei Hu, Adam Overvig, Junjie Li, Cheng-Wei Qiu, Andrea Alu, Yuri S. Kivshar, Xiangping Li
Summary: The authors propose a design of planar chiral metasurfaces that exhibit ultrahigh quality factors and near-perfect circular dichroism. They utilize the physics of chiral bound states in the continuum and demonstrate experimentally the chiroptical responses with high quality factors and near-perfect circular dichroism at optical frequencies. The design allows for flexibility in enhancing and tuning the chirality and quality factors of the metasurfaces.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Julian Klein, Zhigang Song, Benjamin Pingault, Florian Dirnberger, Hang Chi, Jonathan B. Curtis, Rami Dana, Rezlind Bushati, Jiamin Quan, Lukas Dekanovsky, Zdenek Sofer, Andrea Alu, Vinod M. Menon, Jagadeesh S. Moodera, Marko Loncar, Prineha Narang, Frances M. Ross
Summary: Atomic-level defects in van der Waals (vdW) materials are essential for quantum technologies and sensing applications. The magnetic semiconductor CrSBr, with a direct gap and rich magnetic phase diagram, exhibits optically active defects that are correlated with the magnetic environment. The narrow defect emission in CrSBr is related to both the bulk magnetic order and an additional defect-induced magnetic order. This study establishes vdW magnets like CrSBr as an exceptional platform for studying defects and creating tailor-made magnetic textures with optical access.
Article
Nanoscience & Nanotechnology
Guangwei Hu, Weiliang Ma, Debo Hu, Jing Wu, Chunqi Zheng, Kaipeng Liu, Xudong Zhang, Xiang Ni, Jianing Chen, Xinliang Zhang, Qing Dai, Joshua D. Caldwell, Alexander Paarmann, Andrea Alu, Peining Li, Cheng-Wei Qiu
Summary: Various optical crystals with opposite permittivity components have been observed and characterized in the mid-infrared regime. These crystals possess hyperbolic polaritons with large-momenta optical modes and wave confinement, making them promising for nanophotonic on-chip technologies. Monoclinic CdWO4 crystals are shown to exhibit symmetry-broken hyperbolic phonon polaritons and offer new opportunities for polaritonic phenomena.
NATURE NANOTECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Andrea Cordaro, Brian Edwards, Vahid Nikkhah, Andrea Alu, Nader Engheta, Albert Polman
Summary: As traditional microelectronic technology reaches its limits in speed and power consumption, there is a strong demand for novel computing strategies. Analogue optical computing has the advantage of processing large amounts of data at high speeds with negligible energy costs. Researchers have recently explored ultrathin optical metasurfaces for real-time image processing, particularly for edge detection. By incorporating feedback, they have also demonstrated that metamaterials can be used to solve complex mathematical problems, although this has been limited to guided-wave systems and large setups. This study presents an ultrathin Si metasurface-based platform for analogue computing, capable of solving Fredholm integral equations of the second kind using free-space visible radiation. The device combines an inverse-designed Si-based metagrating with a semitransparent mirror to perform the required Neumann series and solve the equation in the analogue domain at the speed of light. The use of visible wavelength operation enables a compact, ultrathin device that can be integrated on a chip and has high processing speeds.
NATURE NANOTECHNOLOGY
(2023)
Editorial Material
Materials Science, Multidisciplinary
Andrea Alu
Summary: Optical Materials Express Editor-in-Chief, Andrea Ali, has introduced new topic categories for the Journal, redefining the Journal scope and better reflecting the current state of this dynamic field of research.
OPTICAL MATERIALS EXPRESS
(2023)
Article
Nanoscience & Nanotechnology
Sander A. . Mann, Heedong Goh, Andrea Alu
Summary: Enabling strong nonlinear optical phenomena requires carefully designed photonic devices to maximize light-matter interactions. Topology optimization has been widely used in optimizing photonic devices due to its efficiency in dealing with large parameter spaces. However, the application of topology optimization in nonlinear effects in dielectric structures is limited.
Article
Nanoscience & Nanotechnology
Nikita Nefedkin, Michele Cotrufo, Andrea Alu
Summary: Nonreciprocity originating from classical interactions among nonlinear scatterers is explored in this work, offering a promising tool for quantum information processing and quantum computing. It is shown that large nonreciprocal responses can be achieved in nonlinear systems by controlling the position and transition frequencies of the atoms, without requiring a nonreciprocal environment. The connection between this effect and the asymmetric population of a slowly decaying dark state is demonstrated.
Article
Optics
Alex Vallone, Nooshin M. Estakhri, Nasim Mohammadi Estakhri
Summary: Machine learning is a promising platform for the forward modeling and inverse design of photonic structures, especially in complex problems where analytical solutions are not feasible. This study focuses on the inverse design of multilayered nanoparticles using a region-specified approach and a small training dataset enhanced via random region specification in a convolutional neural network. The trained model successfully designs nanoparticles with high absorption levels and different absorption-to-scattering ratios.
JOURNAL OF PHYSICS-PHOTONICS
(2023)
Article
Optics
Asaf Farhi, Ahmed Mekawy, Andrea Alu, Douglas Stone
Summary: This paper analyzes the time-domain dynamics of resonators supporting exceptional points (EPs). It is found that EPs expand the class of waveforms that can be perfectly captured and improve the performance for energy storage and transduction. The analytical derivation and demonstration for several examples of coupled optical resonator systems are provided.
