The confinement of surface plasmon polaritons (SPPs) offers strong field strengths also for longitudinal field components. Phenomena like spin-momentum locking can thus be exploited for novel functionality in nanodevi...
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The confinement of surface plasmon polaritons (SPPs) offers strong field strengths also for longitudinal field components. Phenomena like spin-momentum locking can thus be exploited for novel functionality in nanodevices. External control of transport or directional coupling of propagating SPPs would be highly interesting for applications. Herein, the coupling of noble metal and magnetic nanoparticles to a silver nanowire acting as SPP waveguide using a hybrid self-assembly approach is demonstrated. A designated setup is reported to isolate and investigate magnetically controlled transport in such devices. Various configurations are measured to quantify the required sensitivity for the typically tiny magnet response at moderate strengths of the magnetic field. Although magnetic control cannot be achieved, the required improvements can be estimated based on a heuristic numerical model. It is suggested using an approach to enhance magnetic response using a combination of metal and magnetic nanoparticles. Such devices can be assembled in principle with self-assembly approach in a multistep process. The confinement of surface plasmon polaritons (SPPs) and spin-momentum locking phenomena can be exploited for novel functionality in nanodevices using an external control of SPPs propagation. In this article, the coupling of noble metal and magnetic nanoparticles to a silver nanowire acting as SPPs waveguide is demonstrated using a hybrid self-assembly approach to investigate an external control of *** (c) 2023 WILEY-VCH GmbH
Integrated silicon plasmonic circuitry is becoming integral for communications and data processing. One key challenge in implementing such optical networks is the realization of optical sources on silicon platforms, d...
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Integrated silicon plasmonic circuitry is becoming integral for communications and data processing. One key challenge in implementing such optical networks is the realization of optical sources on silicon platforms, due to silicon's indirect bandgap. Here, we present a silicon-based metal-encapsulated nanoplasmonic waveguide geometry that can mitigate this issue and efficiently generate light via third-harmonic generation (THG). Our waveguides are ideal for such applications, having strong power confinement and field enhancement, and an effective use of the nonlinear core area. This unique device was fabricated, and experimental results show efficient THG conversion efficiencies of eta = 4.9 x 10(-4), within a core footprint of only 0.24 mu m2. Notably, this is the highest absolute silicon-based THG conversion efficiency presented to date. Furthermore, the nonlinear emission is not constrained by phase matching. These waveguides are envisioned to have crucial applications in signal generation within integrated nanoplasmonic circuits.
We propose and demonstrate a broadband 3-dB power splitter based on a non-Hermitian triplet waveguide fabricated on a silicon-on-insulator (SOI) platform. By exploiting mirror symmetry, we show that the triplet can be...
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We propose and demonstrate a broadband 3-dB power splitter based on a non-Hermitian triplet waveguide fabricated on a silicon-on-insulator (SOI) platform. By exploiting mirror symmetry, we show that the triplet can be decoupled into two virtual subspaces: a Hermitian subspace featuring a lossless zero mode and a non-Hermitian subspace supporting lossy modes. The zero mode, with its intensity equally distributed between the outer two waveguides, plays a crucial role in achieving broadband performance, effectively suppressing mode competition and maintaining stable splitting against dimensional errors. Experimentally, the 1-dB operational bandwidth of the splitter is confirmed to exceed 70 nm, ranging from 1480 nm to 1550 nm. Furthermore, this approach can be directly extended to any 1xn power splitter, providing a scalable and robust solution for photonic integration. (c) 2025 Optica Publishing Group. All rights, including for similar technologies, are reserved.
Here we experimentally demonstrate an electrically pumped surface plasmon waveguide laser, which generates surface plasmons on a flat metal surface. The laser is formed by a narrow strip of electrically pumped semicon...
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Here we experimentally demonstrate an electrically pumped surface plasmon waveguide laser, which generates surface plasmons on a flat metal surface. The laser is formed by a narrow strip of electrically pumped semiconductor optical gain medium placed close to a flat silver surface. The gain medium is electrically pumped via long thin laterally connected semiconductor pathways. The semiconductor gain medium acts as a dielectric load to localize the surface plasmon component on the silver surface. Lasing is demonstrated at wavelengths near 1500 nm with a section of waveguide which forms a Fabry-Perot cavity. The lasing mode is shown to be the predicted zero order transverse magnetic mode, which allows the greatest miniaturization of the laser size. Lasing is demonstrated at low temperatures due to fabrication imperfections. However, analysis of the results shows the structure has good potential for room temperature operation. With the fabricated device parameters a material gain of 55 cm-1 is required in theory to overcome metal losses, and the confinement factor for the laser waveguide is 0.5. This laser demonstration shows that lateral electrical pumping schemes can be realized. Furthermore, that the schemes provide sufficient pumping of the gain medium to overcome metal losses in surface plasmon waveguides.
A general approach is proposed for calculating the transmission characteristics of a tapered section between two shielded waveguides with rectangular cross sections. The calculation technique is based on the Lorentz i...
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A general approach is proposed for calculating the transmission characteristics of a tapered section between two shielded waveguides with rectangular cross sections. The calculation technique is based on the Lorentz integral relationship and applied to solve the problem on matching rectangular waveguides with different cross sections.
In this paper, we study the problem of wave scattering from finite heterogeneities (in 1- and 2-D) by using the Atomistic Green's Function (AGF) technique. The application of AGF to classical wave scattering probl...
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In this paper, we study the problem of wave scattering from finite heterogeneities (in 1- and 2-D) by using the Atomistic Green's Function (AGF) technique. The application of AGF to classical wave scattering problems is novel and it allows us to compute the Green's function of the scatterers, which is central to understanding the dynamics of the problem and is, in general, difficult to obtain. The AGF method also allows us to efficiently compute the numerically exact transmission and reflection coefficients without the need for any artificial truncating boundaries such as perfectly matched layers or Dirichlet to Neumann (DtN) maps. The technique generates the effective Hamiltonian of the wave scatterer and uses it to compute the numerically exact Green's function of the scatterer. The formalism presented here is especially suited to scattering problems involving waveguides, phononic crystals, metamaterials, and metasurfaces. To illustrate the utility of the technique, we demonstrate the application of the method to three scattering problems: scattering from a slab (1D), scattering from a finite phononic crystal (1D), and scattering from defects in a waveguide (2D).
Integrated nonlinear optical devices play an important role in modern optical communications;however, conventional on-chip optical devices with homogeneous or periodic translation dimensions generally have limited ban...
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Integrated nonlinear optical devices play an important role in modern optical communications;however, conventional on-chip optical devices with homogeneous or periodic translation dimensions generally have limited bandwidth when applied to nonlinear optical applications. So far there lacks a general method to design compact nonlinear optical devices capable of operating over a broadband continuous frequency range. In this work we propose a general strategy based on transformation optics to design curved accelerating waveguides with spatially gradient curvatures, which can achieve broadband nonlinear frequency conversion on chip. Through rigorous analytical calculation, we show that increasing the acceleration (that is, the gradient in the waveguide curvature) broadens the output signal spectrum in the nonlinear process. In this experiment we use sum-frequency generation for infrared signal upconversion as an example and fabricated a variety of curved accelerating waveguides using thin-film lithium niobate on insulators. Efficient sum-frequency generation is observed over a broadband continuous spectrum. Our conformal mapping approach offers a platform for various nonlinear optical processes and works in any frequency range, including visible, infrared and terahertz bands. Apart from lithium niobate on insulators, our approach is also compatible with other nonlinear materials such as silicon, silicon nitride and chalcogenide glasses and so on. Conformal transformation optics is exploited to design curved accelerating waveguides with spatially gradient curvatures to boost the nonlinear efficiency and broaden the bandwidth of the nonlinear optical processes in the waveguides.
We propose and demonstrate an accurate method of measuring the effective refractive index and thermo-optic coefficient of silicon-on-insulator waveguides in the entire C-band using three Mach-Zehnder interferometers. ...
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We propose and demonstrate an accurate method of measuring the effective refractive index and thermo-optic coefficient of silicon-on-insulator waveguides in the entire C-band using three Mach-Zehnder interferometers. The method allows for accurate extraction of the wavelength dispersion and takes into account fabrication variability. Wafer scale measurements are performed and the effective refractive index variations are presented for three different waveguide widths: 450, 600, and 800 nm, for the TE polarization. The presented method is generic and can be applied to other waveguide geometries and material systems and for different wavelengths and polarizations.
Quantum effects in photosynthetic energy transport in nature, especially for the typical Fenna-Matthews-Olson (FMO) complexes, are extensively studied in quantum biology. Such energy transport processes can be investi...
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Quantum effects in photosynthetic energy transport in nature, especially for the typical Fenna-Matthews-Olson (FMO) complexes, are extensively studied in quantum biology. Such energy transport processes can be investigated as open quantum systems that blend the quantum coherence and environmental noise, and have been experimentally simulated on a few quantum devices. However, the existing experiments always lack a solid quantum simulation for the FMO energy transport due to their constraints to map a variety of issues in actual FMO complexes that have rich biological meanings. Here we successfully map the full coupling profile of the seven-site FMO structure by comprehensive characterisation and precise control of the evanescent coupling of the three-dimensional waveguide array. By applying a stochastic dynamical modulation on each waveguide, we introduce the base site energy and the dephasing term in coloured noise to faithfully simulate the power spectral density of the FMO complexes. We show our photonic model well interprets the phenomena including reorganisation energy, vibrational assistance, exciton transfer and energy localisation. We further experimentally demonstrate the existence of an optimal transport efficiency at certain dephasing strength, providing a window to closely investigate environment-assisted quantum transport.
We propose the double-metal-film waveguides for terahertz (THz) wave guiding. The loss and field features are analyzed. In the application of wavelength analysis, the formula of the wavelength has been derived, and it...
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We propose the double-metal-film waveguides for terahertz (THz) wave guiding. The loss and field features are analyzed. In the application of wavelength analysis, the formula of the wavelength has been derived, and it can be used to analyze the wavelength of the THz sources according to mode field distribution in the dielectric-substrate slab. The penetrating capability of the THz wave is also discussed for different structures. When there is more energy in the dielectric-substrate slab, it will be better for wavelength analysis. (C) 2015 Optical Society of America
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