- 标题
- 摘要
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- 实验方案
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Optical Beam Steering With an All-Silicon Particle Chain
摘要： Optical beam steering is fundamental and important in optics and photonics. In this study, we report a nearly total negative angle refraction over a wide angle range when an optical beam passes through an all-silicon particle chain. This phenomenon is concluded as the product of an interference effect of the double modes excited in the chain, which has potential applications for on-chip beam manipulation, routing, and filtering for its simplicity and low loss nature.
关键词： nanophotonics,Nanoparticles,optical beams
更新于2025-09-11 14:15:04
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Mitigating Chromatic Dispersion with Hybrid Optical Metasurfaces
摘要： Metasurfaces control various properties of light via scattering across a large number of subwavelength-spaced nanostructures. Although metasurfaces appear to be ideal photonic platforms for realizing and designing miniaturized devices, their chromatic aberrations have hindered the large-scale deployment of this technology in numerous applications. Wavelength-dependent diffraction and resonant scattering effects usually limit their working operation wavelengths. In refractive optics, chromatic dispersion is a significant problem and is generally treated by cascading multiple lenses into achromatic doublets, triplets, and so on. Recently, broadband achromatic metalenses in the visible have been proposed to circumvent chromatic aberration but their throughput efficiency is still limited. Here, the dispersion of refractive components is corrected by leveraging the inherent dispersion of metasurfaces. Hybrid refractive-metasurface devices, with nondispersive refraction in the visible, are experimentally demonstrated. The dispersion of this hybrid component, characterized by using a Fourier plane imaging microscopy setup, is essentially achromatic over about 150 nm in the visible. Broadband focusing with composite plano-convex metasurface lenses is also proposed. These devices could find applications in numerous consumer optics, augmented reality components, and all applications including imaging for which monochromatic performance is not sufficient.
关键词： metasurfaces,nanophotonics,hybrid optics,dispersion
更新于2025-09-10 09:29:36
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - Femto-Farad Optoelectronic Coupling and Low-Latency Nanophotonic Computing
摘要： We demonstrate that the capacitance of OE/EO conversion devices, such as photo-detectors and electro-optic modulators, can be reduced down to a fF level by use of photonic crystals. This enables us to drastically reduce the energy efficiency of OE/EO conversion. We show that on-chip high-speed photo-receivers can be operated without any electrical power, and pseudo-all-optical-nonlinear devices can be realized by a combination of a fF photodetector and a fF electro-optic modulator. Integrated nanophotonics technologies, including those fF-optoelectronic devices, will enable optical pass-gate logic circuits for low-latency optical computation. We present our novel designs for various examples including optical full adder circuits. In addition, we show linear optic gates for logic functions which enable extremely small latency.
关键词： photodetector,nanophotonics,optical computing,optical transistor,electro-optic modulator,photonic crystal
更新于2025-09-10 09:29:36
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[IEEE 2018 IEEE Research and Applications of Photonics In Defense Conference (RAPID) - Miramar Beach, FL, USA (2018.8.22-2018.8.24)] 2018 IEEE Research and Applications of Photonics In Defense Conference (RAPID) - Wideband Mid-IR Semiconductor Resonant Reflectors
摘要： Mid-IR resonant reflectors are presented offering wideband polarized and unpolarized responses. Devices are fabricated from durable and commercially available IR transparent semiconductor materials, offering the possibility of rugged and economical opto-electronic integration.
关键词： Nanophotonics,Optical resonators,Micromirrors
更新于2025-09-10 09:29:36
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Single crystal diamond membranes and photonic resonators containing germanium vacancy color centers
摘要： Single crystal diamond membranes that host optically active emitters are highly attractive components for integrated quantum nanophotonics. In this work we demonstrate bottom-up synthesis of single crystal diamond membranes containing the germanium vacancy (GeV) color centers. We employ a lift-off technique to generate the membranes and perform chemical vapour deposition in a presence of a germanium source to realize the in-situ doping. Finally, we show that these membranes are suitable for engineering of photonic resonators such as microdisk cavities with quality factors of ~ 1500. The robust and scalable approach to engineer single crystal diamond membranes containing emerging color centers is a promising pathway for realization of diamond integrated quantum nanophotonic circuits on a chip.
关键词： germanium vacancy,Diamond,microring,nanophotonics,membranes,cavity
更新于2025-09-10 09:29:36
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Exact Multipolar Decompositions with Applications in Nanophotonics
摘要： The multipolar decomposition of electromagnetic sources is an important tool for the study of light–matter interactions in general, and optical materials in particular. Here, a report is given on recent progress in the multipolar decomposition of electromagnetic sources. First, the exact and simple expressions for the multipolar moments of electric current density distributions are reviewed, and then, the results are extended to multipolar moments of magnetization current density distributions due to intrinsic spin. The consideration of both electric and magnetic sources allows to establish the conditions for sources of pure handedness. Scripts are provided that facilitate the computation of multipolar moments of arbitrary order. The work and the included examples of use are placed in the context of nanophotonics and metamaterials, and an outlook for applications in these and other fields is provided.
关键词： light–matter interactions,nanophotonics,multipole moments,optical antennas,theory
更新于2025-09-10 09:29:36
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Scalable, Highly Uniform, and Robust Colloidal Mie Resonators for All-Dielectric Soft Meta-Optics
摘要： All-dielectric nanoparticles (NPs) with high (>3.0) or moderate (1.7–3.0) refractive indices have become fundamental to meta-optics, as they enable low-loss, low-heating, and quenching-free magnetodielectric Mie resonances, which are difficult to achieve by use of plasmonic counterparts. However, a scalable and versatile synthetic route for such magnetodielectric NPs retaining high uniformity, roundness, and robustness has remained elusive. Thus, soft self-assembly still represents an underutilized method in the optical engineer’s toolset, which in turn limits the accessible range of meta-optics. Herein, a gram-scale and versatile synthesis of dielectric colloidal Mie resonators is presented, in which selenous acid precursors are converted into highly uniform, crystalline colloids by a low demand reaction. These crystalline selenium (c-Se) colloids enable strong electric and magnetic resonances due to their moderate refractive index (2.8–3.2 at optical frequencies), while simultaneously satisfying the requirements of high uniformity, roundness, and robustness. Even with these exotic properties, c-Se colloids are successfully self-assembled into various all-dielectric meta-optics systems including (i) metafluids exhibiting directional scattering, (ii) metamolecules with nanogap-dielectric resonances, and (iii) metacrystals with magnetodielectric bandgaps. The design space of all-dielectric meta-optics will be greatly expanded by utilizing soft self-assembly of c-Se colloids.
关键词： soft nanophotonics,self-assembly,colloids,selenium,3D all-dielectric meta-optics
更新于2025-09-10 09:29:36
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - Second-Harmonic Generation by Mie-resonant Nanoparticles with Bulk Quadratic Nonlinearity
摘要： We study resonantly enhanced second-harmonic generation (SHG) by dielectric nanoparticles made of noncentrosymmetric materials with bulk quadratic nonlinearity. By combining analytical and numerical methods, we analyze the multipolar nature of the second-harmonic generated fields in AlGaAs and BaTiO3 nanoparticles optically excited in the vicinity of the low-order Mie resonances, with a particular focus on the magnetic dipole resonance. We derive selection rules for the multipolar composition of the nonlinear radiation depending on the symmetry of the crystalline structure and polarization of the incident light. The developed description can be instructive for design of highly-efficient nonlinear optical nanoantennas with reconfigurable radiation characteristics.
关键词： second-harmonic generation,nonlinear scattering,nanophotonics,Mie resonances,high-index nanoparticles
更新于2025-09-10 09:29:36
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Wavelength-Flattened Directional Coupler Based Mid-Infrared Chemical Sensor Using Bragg Wavelength in Subwavelength Grating Structure
摘要： In this paper, we report a compact wavelength-flattened directional coupler (WFDC) based chemical sensor featuring an incorporated subwavelength grating (SWG) structure for the mid-infrared (MIR). By incorporating a SWG structure into directional coupler (DC), the dispersion in DC can be engineered to allow broadband operation which is advantageous to extract spectroscopic information for MIR sensing analysis. Meanwhile, the Bragg reflection introduced by the SWG structure produces a sharp trough at the Bragg wavelength. This sharp trough is sensitive to the surrounding refractive index (RI) change caused by the existence of analytes. Therefore, high sensitivity can be achieved in a small footprint. Around fivefold enhancement in the operation bandwidth compared to conventional DC is achieved for 100% coupling efficiency in a 40 μm long WFDC experimentally. Detection of dichloromethane (CH2Cl2) in ethanol (C2H5OH) is investigated in a SWG-based WFDC sensor 136.8 μm long. Sensing performance is studied by 3D finite-difference time domain (FDTD) simulation while sensitivity is derived by computation. Both RI sensing and absorption sensing are examined. RI sensing reveals a sensitivity of ?0.47% self-normalized transmitted power change per percentage of CH2Cl2 concentration while 0.12% change in the normalized total integrated output power is realized in the absorption sensing. As the first demonstration of the DC based sensor in the MIR, our device has the potential for tertiary mixture sensing by utilizing both changes in the real and imaginary part of RI. It can also be used as a broadband building block for MIR application such as spectroscopic sensing system.
关键词： subwavelength grating,waveguide coupler,nanophotonics,photonics sensors,mid-infrared
更新于2025-09-10 09:29:36
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Adjoint method and inverse design for nonlinear nanophotonic devices
摘要： The development of inverse design, where computational optimization techniques are used to design devices based on certain specifications, has led to the discovery of many compact, non-intuitive structures with superior performance. Among various methods, large-scale, gradient-based optimization techniques have been one of the most important ways to design a structure containing a vast number of degrees of freedom. These techniques are made possible by the adjoint method, in which the gradient of an objective function with respect to all design degrees of freedom can be computed using only two full-field simulations. However, this approach has so far mostly been applied to linear photonic devices. Here, we present an extension of this method to modeling nonlinear devices in the frequency domain, with the nonlinear response directly included in the gradient computation. As illustrations, we use the method to devise compact photonic switches in a Kerr nonlinear material, in which low-power and high-power pulses are routed in different directions. Our technique may lead to the development of novel compact nonlinear photonic devices.
关键词： nanophotonics,Inverse design,integrated photonics,optical switching,nonlinear optics
更新于2025-09-10 09:29:36