- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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The Role of Rayleigh-Wood Anomalies and Surface Plasmons in Optical Enhancement for Nano-Gratings
摘要： We propose and report on the design of a 1-D metallo-dielectric nano-grating on a GaAs substrate. We numerically study the impact of grating period, slit and wire widths, and irradiating angle of incidence on the optical response. The optimal wire width, w = 160 nm, was chosen based on previous results from investigations into the influence of wire width and nano-slit dimensions on optical and electrical enhancements in metal-semiconductor-metal photodetectors. In this present project, resonant absorption and reflection modes were observed while varying the wire and nano-slit widths to study the unique optical modes generated by Rayleigh-Wood anomalies and surface plasmon polaritons. We observed sharp and diffuse changes in optical response to these anomalies, which may potentially be useful in applications such as photo-sensing and photodetectors. Additionally, we found that varying the slit width produced sharper, more intense anomalies in the optical spectrum than varying the wire width.
关键词： Rayleigh-Wood anomalies,photo-sensing,nano-optics,plasmonics
更新于2025-09-23 15:21:01
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Near-field observation of guided-mode resonances on a metasurface via dielectric nanosphere excitation
摘要： We study laser-induced guided-mode resonances on an ultra-thin anisotropic metallic metasurface using direct near-field mapping. Coupling of the incident light to the surface waves is provided by a resonant laser-printed silicon nanosphere placed on the metasurface using nano-manipulation under electron-beam supervision. To visualize the propagation of the guided modes, we employ scattering-type scanning near-field optical microscopy in the near-infrared region (850 nm). The guided-mode resonances excited by the nanosphere demonstrate vanishing anisotropy due to weak confinement at the metasurface/air interface. We also extract the wavenumber of the observed modes through Fourier transformation of the measured near-field maps and find it to be in good agreement with numerical calculations.
关键词： Metasurface,Surface waves,Anisotropy,s-SNOM,Guided-mode resonance,Nano-Optics
更新于2025-09-23 15:21:01
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Ultrabroadband plasmonic induced transparency in random metamaterial with nanocavity
摘要： A three-dimensional (3D) metamaterial is very easily assembled as a stacked structure with two physical vapor deposition layers, one metallic and one dielectric, and with a spray of gold nanospheres (GNS) on top. The first planar metasurface is a semicontinuous gold nanocomposite which is transformed into a “dark metasurface” when embedded in a dielectric nanocavity. The second metasurface is a radiative mirror composed of the self-arranged GNS at the nanocavity’s surface. The two random metasurfaces are strongly coupled through their near field inside the nanocavity. Plasmonic induced transparency is observed at normal incidence over a very wide spectral bandwidth of a few hundred terahertz from the visible to the NIR. The induced transmission maximum occurs in a spectral region where the scattering cross section from the GNS is maximum. Critical coupling between the two metasurfaces is achieved with multiple deposits of GNS and the transition from induced transparency to induced absorption is experimentally observed. Such a simple 3D metamaterial could be used to enhance non-linear optical effects, optical switching and slow light generation in the NIR.
关键词： Plasmonics,Nanocomposites,Nanospheres,Critical coupling,Metamaterials,Nano optics
更新于2025-09-19 17:13:59
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Polarization nano-tomography of tightly focused light landscapes by self-assembled monolayers
摘要： Recently, four-dimensional (4D) functional nano-materials have attracted considerable attention due to their impact in cutting-edge fields such as nano-(opto)electronics, -biotechnology or -biomedicine. Prominent optical functionalizations, representing the fourth dimension, require precisely tailored light fields for its optimal implementation. These fields need to be like-wise 4D, i.e., nano-structured in three-dimensional (3D) space while polarization embeds additional longitudinal components. Though a couple of approaches to realize 4D fields have been suggested, their breakthrough is impeded by a lack of appropriate analysis techniques. Combining molecular self-assembly, i.e., nano-chemistry, and nano-optics, we propose a polarization nano-tomography of respective fields using the functional material itself as a sensor. Our method allows a single-shot identification of non-paraxial light fields at nano-scale resolution without any data post-processing. We prove its functionality numerically and experimentally, elucidating its amplitude, phase and 3D polarization sensitivity. We analyze non-paraxial field properties, demonstrating our method’s capability and potential for next generation 4D materials.
关键词： four-dimensional (4D) functional nano-materials,nano-optics,non-paraxial light fields,self-assembled monolayers (SAMs),polarization nano-tomography
更新于2025-09-12 10:27:22
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Conductive polymer nanoantennas for dynamic organic plasmonics
摘要： Being able to dynamically shape light at the nanoscale is one of the ultimate goals in nano-optics. Resonant light–matter interaction can be achieved using conventional plasmonics based on metal nanostructures, but their tunability is highly limited due to a fixed permittivity. Materials with switchable states and methods for dynamic control of light–matter interaction at the nanoscale are therefore desired. Here we show that nanodisks of a conductive polymer can support localized surface plasmon resonances in the near-infrared and function as dynamic nano-optical antennas, with their resonance behaviour tunable by chemical redox reactions. These plasmons originate from the mobile polaronic charge carriers of a poly(3,4-ethylenedioxythiophene:sulfate) (PEDOT:Sulf) polymer network. We demonstrate complete and reversible switching of the optical response of the nanoantennas by chemical tuning of their redox state, which modulates the material permittivity between plasmonic and dielectric regimes via non-volatile changes in the mobile charge carrier density. Further research may study different conductive polymers and nanostructures and explore their use in various applications, such as dynamic meta-optics and reflective displays.
关键词： plasmonics,nano-optics,conductive polymers,nanoantennas,dynamic control
更新于2025-09-12 10:27:22
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3D Multi-Branched SnO2 Semiconductor Nanostructures as Optical Waveguides
摘要： Nanostructures with complex geometry have gathered interest recently due to some unusual and exotic properties associated with both their shape and material. 3D multi-branched SnO2 one-dimensional nanostructrures, characterized by a “node”—i.e., the location where two or more branches originate, are the ideal platform to distribute signals of di?erent natures. In this work, we study how this particular geometrical con?guration a?ects light propagation when a light source (i.e., laser) is focused onto it. Combining scanning electron microscopy (SEM) and optical analysis along with Raman and Rayleigh scattering upon illumination, we were able to understand, in more detail, the mechanism behind the light-coupling occurring at the node. Our experimental ?ndings show that multi-branched semiconductor 1D structures have great potential as optically active nanostructures with waveguiding properties, thus paving the way for their application as novel building blocks for optical communication networks.
关键词： SnO2,waveguiding e?ect in nanostructures,3D multi-branched nanostructures,nanowires,light scattering,tin oxide nanostructure,nano-optics
更新于2025-09-11 14:15:04
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The photonic candle
摘要： Using light to manipulate small particles has proven an indispensable tool for ‘tweezing’, sorting and force measurements. To achieve effective optical traps with high ‘stiffness’, researchers often go to great lengths to tailor light fields, for example by using holographic elements. Now, Aliaksandra Ivinskaya and colleagues from Russia, the USA, the UK and Israel predict that small particles can be manipulated using a plane wave of light and a simple flat surface of an anisotropic media supporting hyperbolic modes. Their hyperbolic metamaterial is composed of metal and dielectric layers and is potentially less affected by losses and offers more broadband capability than purely plasmonic approaches. In their theoretical study a small dielectric sphere near a hyperbolic metamaterial is considered. The particle is sufficiently small to provide the required momentum to excite both surface plasmon and bulk hyperbolic waves from incident plane waves. Strong optical pulling forces were predicted over the 400–800 nm wavelength range thanks to the broadband high density of states of hyperbolic modes.
关键词： hyperbolic modes,nano-optics,optical manipulation,metasurface,plasmon
更新于2025-09-09 09:28:46
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Ultrawide tunability
摘要： Using light to manipulate small particles has proven an indispensable tool for ‘tweezing’, sorting and force measurements. To achieve effective optical traps with high ‘stiffness’, researchers often go to great lengths to tailor light fields, for example by using holographic elements. Now, Aliaksandra Ivinskaya and colleagues from Russia, the USA, the UK and Israel predict that small particles can be manipulated using a plane wave of light and a simple flat surface of an anisotropic media supporting hyperbolic modes. Their hyperbolic metamaterial is composed of metal and dielectric layers and is potentially less affected by losses and offers more broadband capability than purely plasmonic approaches. In their theoretical study a small dielectric sphere near a hyperbolic metamaterial is considered. The particle is sufficiently small to provide the required momentum to excite both surface plasmon and bulk hyperbolic waves from incident plane waves. Strong optical pulling forces were predicted over the 400–800 nm wavelength range thanks to the broadband high density of states of hyperbolic modes.
关键词： hyperbolic modes,nano-optics,optical manipulation,metasurface,plasmon
更新于2025-09-09 09:28:46
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Compact and efficient
摘要： Using light to manipulate small particles has proven an indispensable tool for ‘tweezing’, sorting and force measurements. To achieve effective optical traps with high ‘stiffness’, researchers often go to great lengths to tailor light fields, for example by using holographic elements. Now, Aliaksandra Ivinskaya and colleagues from Russia, the USA, the UK and Israel predict that small particles can be manipulated using a plane wave of light and a simple flat surface of an anisotropic media supporting hyperbolic modes. Their hyperbolic metamaterial is composed of metal and dielectric layers and is potentially less affected by losses and offers more broadband capability than purely plasmonic approaches. In their theoretical study a small dielectric sphere near a hyperbolic metamaterial is considered. The particle is sufficiently small to provide the required momentum to excite both surface plasmon and bulk hyperbolic waves from incident plane waves. Strong optical pulling forces were predicted over the 400–800 nm wavelength range thanks to the broadband high density of states of hyperbolic modes.
关键词： hyperbolic modes,nano-optics,optical manipulation,metasurface,plasmon
更新于2025-09-09 09:28:46
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Metasurface with pull
摘要： Using light to manipulate small particles has proven an indispensable tool for ‘tweezing’, sorting and force measurements. To achieve effective optical traps with high ‘stiffness’, researchers often go to great lengths to tailor light fields, for example by using holographic elements. Now, Aliaksandra Ivinskaya and colleagues from Russia, the USA, the UK and Israel predict that small particles can be manipulated using a plane wave of light and a simple flat surface of an anisotropic media supporting hyperbolic modes. Their hyperbolic metamaterial is composed of metal and dielectric layers and is potentially less affected by losses and offers more broadband capability than purely plasmonic approaches. In their theoretical study a small dielectric sphere near a hyperbolic metamaterial is considered. The particle is sufficiently small to provide the required momentum to excite both surface plasmon and bulk hyperbolic waves from incident plane waves. Strong optical pulling forces were predicted over the 400–800 nm wavelength range thanks to the broadband high density of states of hyperbolic modes.
关键词： metasurface,hyperbolic modes,plasmon,nano-optics,optical manipulation
更新于2025-09-04 15:30:14