Amplified linear and nonlinear chiral sensing assisted by anapole modes in hybrid metasurfaces
Guillermo Serrera, Javier González-Colsa, Pablo Albella
备注：
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 124, 251701 (2024) and may be found at 10.1063/5.0212393. Copyright (2024) Authors. This article is distributed under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International (CC BY-NC-ND) License
The interaction between chiral molecules and circularly polarized light is largely influenced by the local optical chirality density. This interaction prompts substantial demand of the design of nanophotonic platforms capable of enhancing such effects across large and accessible volumes. Such a magnification requires nanostructures that provide strong electric and magnetic field enhancements while preserving the phase relation of circular light. Dielectric nanostructures, particularly those able to support resonances, are ideal candidates for this task due to their capacity for high electric and magnetic field enhancements. On the other hand, efficient third harmonic generation calls for strong electric field resonances within dielectric materials, a feature often boosted by incorporating plasmonic materials into hybrid systems. In this work, we numerically propose a coupled silicon disk-gold ring system that can exploit the anapole-induced field confinement to provide a broadband magnified circular dichroism under realistic conditions, reaching values up to a 230-fold enhancement. We also demonstrate that this structure can be employed as an efficient third harmonic generator which, when integrated with chiral media, enables an 800-fold enhancement in circular dichroism. Furthermore, we show that pulsed illumination at intensities up to 10 GW/cm2 does not induce temperature increments that could potentially damage the samples. These findings suggest that this system can be a promising and versatile approach towards ultrasensitive chiral sensing.
Metasurfaces have attracted a great deal of attention from researchers due to their prominent optical properties. In particular, metasurfaces may consist of structures possessing optical anapole resonances with strong field confinement and substantially suppressed scattering. As a result, such nanostructures display enhanced nonlinear optical properties. In this paper by means of three-dimensional finite-difference time-domain simulations, the ability of anapole modes in high-index dielectric metasurfaces with circular nanopores is shown. In the vicinity of the anapole state, the effective opt…
The optical anapole resonances in nanostructures display strong field confinement and substantially suppressed scattering. In this study using three-dimensional finite-difference time-domain simulations, it is shown that high refractive index dielectric nanohole array metasurfaces having different profiles of the holes can possess the anapole state. The multipole decomposition including the dipole electric toroidal moment for the lattice elements of the arrays is provided. The anapole state in the lattice elements is illustrated by time-averaged distributions of the energy. As a result, high-i…
Common optical metasurfaces are 2-dimensional functional devices composed of periodically arranged subwavelength constituents. Here, we achieved the positional-disorder-immune metasurfaces composed of core-shell cylinders which successively exhibit the magnetic dipole (MD) resonant, non-radiating anapole, and electric dipole (ED) resonant modes when their outer radii are fixed and the inner radii changes continuously in a range. The performances of the metasurfaces under a periodically structural design are not degraded even when the positions of the cylinders are subjected to random and consi…
We present all-dielectric polaritonic metasurfaces consisting of properly sculptured cylinders to sustain the dynamic anapole, i.e. a non-radiating alternating current distribution. One way for the anapole to emerge, is by combining modes based on the first and the fourth Mie resonance of a cylinder made of high permittivity LiTaO$_3$ for operation in the low THz. The circular cross-section of each cylinder varies periodically along its length in a binary way, from small to large, while its overall circular symmetry has to be broken in order to remove parasitic magnetic modes. Small cross-sect…
Magneto-optical intensity effect in a transparent perforated all-dielectric metasurface with an anapole state
Moscow Institute of Physics and Technology (National Research University) (MIPT)（莫斯科物理技术国立大学）；Faculty of Physics, Lomonosov Moscow State University（莫斯科国立大学物理系）；Russian Quantum Center (RQC) (International Center for Quantum Optics and Quantum Technologies)（俄罗斯量子中心）；Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research（塔塔基础研究所凝聚态物理与材料科学系）；National Physical Laboratory（国家物理实验室）
The nonlinear optical properties of the high index nanoparticles are boosted at the anapole state. Researchers intensively study this phenomenon as promising for various applications. In this work, the nonlinear optical Kerr effect of disordered and square lattice metasurfaces of GaP nanodisks is investigated as a function of the disk size in the vicinity of the anapole state at the wavelength of 532 nm. When the sizes of the nanodisks are close to the anapole state, the effective second order refractive index of the metasurface increases exponentially. On approaching the anapole state, the si…
Enhanced magneto-optical intensity effect in a helicity-preserving all-dielectric metasurface at Mie resonances and the anapole state
Russian Quantum Center（俄罗斯量子中心）；Moscow Institute of Physics and Technology (MIPT)（莫斯科物理技术学院）；Faculty of Physics, M.V. Lomonosov Moscow State University（莫斯科国立大学物理系）；National Engineering Research Center of Electromagnetic Radiation Control Materials, University of Electronic Science and Technology of China（电子科技大学电磁辐射控制材料国家工程研究中心）；State Key Laboratory of Electronic Thin-Films and Integrated Devices, University of Electronic Science and Technology of China（电子科技大学电子薄膜与集成器件国家重点实验室）
All-dielectric nanophotonics has become one of the most active fields of research in modern optics, largely due to the opportunities offered by the simultaneous resonant control of electric and magnetic components of light at the nanoscale. In this rapidly evolving scenario, the possibility to design artificial Huygens sources by overlapping electric and magnetic resonances has established a new paradigm in flat optics, bringing devices closer to efficient wavefront shaping with a direct phase engineering at the level of the individual meta-atoms. However, their efficiency is fundamentally lim…
The ability to manipulate electric and magnetic components of light at the nanoscale delivered by dielectric and semiconductor components is paving the way towards novel types of sources and nanoantennae with exceptional electromagnetic signatures, flexible and tunable metasurface architectures, enhanced light harvesting structures, etc. Recently, the anapoles states arising from the destructive interference of basic multipoles and their toroidal counterparts have been widely exploited to cancel radiation from an individual scattering channel of isolated nanoresonators, while displaying nontri…
Amplified up-conversion of electromagnetic waves using time-varying metasurfaces
ARC Centre of Excellence for Transformative Meta-Optical Systems (TMOS), Research School of Physics, The Australian National University（澳大利亚国立大学变革性超光学系统卓越研究中心物理研究学院）；Instituto de Telecomunicações and Department of Electronics, Telecommunications and Informatics, University of Aveiro（阿威罗大学电信研究所电子、电信与信息系）
Modern nanophotonics has witnessed the rise of "electric anapoles", destructive interferences of electric dipoles and toroidal electric dipoles, actively exploited to cancel electric dipole radiation from nanoresonators. However, the inherent duality of Maxwell's equations suggests the intriguing possibility of "magnetic anapoles", involving a nonradiating composition of a magnetic dipole and a magnetic toroidal dipole. Here, we predict, fabricate and observe experimentally via a series of dark field spectroscopy measurements a hybrid anapole of mixed electric and magnetic character, with all …
Anapole states associated with the resonant suppression of electric-dipole scattering exhibit minimized extinction and maximized storage of electromagnetic energy inside a particle. Using numerical simulations, optical extinction spectroscopy and amplitude-phase near-field mapping of silicon dielectric disks, we demonstrate high-order anapole states in the near-infrared wavelength range (900-1700 nm). We develop the procedure for unambiguously identifying anapole states by monitoring the normal component of the electric near-field and experimentally detect the first two anapole states as verif…
Metasurfaces consisting of hybrid metal/dielectric nanostructures carry advantages of both material platforms. The hybrid structures can not only tightly confine subwavelength electromagnetic fields but also lower the absorption losses. Such optical characteristics are difficult to realize in metamaterials with only metal or dielectric structures. Hybrid designs also expand the scope of material choices and the types of optical modes that can be excited in a metasurface, thereby allowing novel light matter interactions. Here we present a metallo-dielectric hybrid metasurface design consisting …
Freed from phase-matching constraints, plasmonic metasurfaces have contributed significantly to the control of the optical nonlinearity and enhancing the nonlinear generation efficiency by engineering subwavelength meta-atoms. However, the high dissipative losses and the inevitable thermal heating limit their applicability in nonlinear nanophotonics. All-dielectric metasurfaces, supporting both electric and magnetic Mie-type resonances in their nanostructures, have appeared as a promising alternative to nonlinear plasmonics. High-index dielectric nanostructures, allowing additional magnetic re…
Frequency conversion processes, such as second- and third-harmonic generation, are one of the most common effects in nonlinear optics which offer many opportunities for photonics, chemistry, material science, characterization, and biosensing. Given the inherently weak nonlinear response of natural materials, one typically relies on optically large samples and complex phase-matching techniques to achieve nonlinear effects. A direct translation of these approaches to small dimensions, however, is extremely challenging, because nonlinear effects locally comparable to the linear response cannot be…
Nonradiating sources of energy have traditionally been studied in quantum mechanics and astrophysics, while receiving a very little attention in the photonics community. This situation has changed recently due to a number of pioneering theoretical studies and remarkable experimental demonstrations of the exotic states of light in dielectric resonant photonic structures and metasurfaces, with the possibility to localize efficiently the electromagnetic fields of high intensities within small volumes of matter. These recent advances underpin novel concepts in nanophotonics, and provide a promisin…
Optically resonant all-dielectric nanostructures attractively exhibit reduced losses compared to their plasmonic counterparts; however, achieving strong field enhancements at the nanoscale, especially within solid-state media, has remained a significant challenge. In this work, we demonstrate how subwavelength modifications to a conventional silicon nanodisk enable strong sub-diffractive and polarization dependent field enhancements in devices supporting anapole-like modes. We examine the electromagnetic properties of both individual and arrayed diabolo nanodisks, which are found to exhibit |E…
