We propose an expanded coupled mode theory to analyze sensing performance in a plasmonic slot waveguide side-coupled with a multimode stub resonator. It is confirmed by the finite-difference time-domain simulations. T...
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We propose an expanded coupled mode theory to analyze sensing performance in a plasmonic slot waveguide side-coupled with a multimode stub resonator. It is confirmed by the finite-difference time-domain simulations. Through adjusting the parameters, we can realize figure of merit (FOM) of similar to 59,010, and the sensitivity S can reach to 75.7. Compared with the plasmonic waveguide systems in recent Letters, our proposed structure has the advantages of easy fabrication, compactness, sensitivity, and high FOM. The proposed theory model and findings provide guidance for fundamental research of the integrated plasmonic nano-sensor applications. (C) 2016 Optical Society of America
We extend the Krylov-subspace-based time-dependent numerical simulation technique for a qubit interacting with photons in a waveguide to the multiple qubit case. We analyze photon scattering from two qubits and derive...
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We extend the Krylov-subspace-based time-dependent numerical simulation technique for a qubit interacting with photons in a waveguide to the multiple qubit case. We analyze photon scattering from two qubits and derive expressions for the bound states in the continuum (BICs). We show how the BIC can be excited. We use the BIC in a recent Pauli-Z gate proposal involving decoherence free subspaces and obtain the gate fidelity as a function of the gate parameters. The techniques presented in this Letter are useful for investigating the time evolution of quantum gates and other many-body systems with multiple quenches in the Hamiltonian. (C) 2016 Optical Society of America
Graphene nano-ribbon waveguides with ultra-short plasmon wavelength are a promising candidate for nanoscale photonic applications. Graphene edge plasmons are the fundamental and lowest losses mode. Through finite elem...
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Graphene nano-ribbon waveguides with ultra-short plasmon wavelength are a promising candidate for nanoscale photonic applications. Graphene edge plasmons are the fundamental and lowest losses mode. Through finite element method, edge plasmons show large effective refractive index and strong field confinement on nanoscale ribbons. The edge plasmons follow a k112 dispersion relation. The wavelengths of the edge plasmons and center plasmons differ by a fixed factor. The width of edge plasmon is inversely proportional to wave vector of edge plasmon kedge. Edge defects associate with graphene nano-ribbon induce extra losses and reduce the propagation length. Cut-off width of edge plasmons reduces with increasing frequency. Cut-off width of center plasmon is enlarged by edge component but the enlargement effect diminishing with the increase of kedge. The results are important for the application of graphene plasmon towards ultra-compact photonic devices. (C) 2016 Elsevier B.V. All rights reserved.
We experimentally investigate the impacts of fabrication error in Si wire-waveguides on the spectral variation of 5th-order coupled resonator optical waveguides (CROWs). In the fabrication of these waveguide devices, ...
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We experimentally investigate the impacts of fabrication error in Si wire-waveguides on the spectral variation of 5th-order coupled resonator optical waveguides (CROWs). In the fabrication of these waveguide devices, 40-nm-node CMOS technology with ArF immersion lithography was used. The characterization of the CROWS was done by using an automatic optical wafer-level probing system. As for the fabrication errors in 440-nm-wide/220-nm-thick waveguides, standard deviations in waveguide cross-sectional size for a single 300-mm wafer were confirmed to be 0.83 nm in width and 0.24 nm in height. The fabricated CROWs in a single wafer exhibited quite similar resonant peak shapes to each other, and also showed a remarkably small standard deviation of 0.67 nm in resonant wavelength, which agrees with the theoretical estimation from the fabrication error. These results show that the precise process control using ArF immersion lithography technology is effective to the reproducible device fabrication for wide-bandwidth optical interconnection. (C) 2015 Elsevier B.V. All rights reserved.
As2S3 glass has a unique combination of optical properties, such as wide transparency in the infrared region and a high nonlinear coefficient. Recently, intense research has been conducted to improve photonic devices ...
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As2S3 glass has a unique combination of optical properties, such as wide transparency in the infrared region and a high nonlinear coefficient. Recently, intense research has been conducted to improve photonic devices using thin materials. In this Letter, highly uniform rectangular single-index and 2 dB/m loss step-index optical tapes have been drawn by the crucible technique. Low-loss (<0.15 dB/cm) single-mode waveguides in chalcogenide glass tapes have been fabricated using femtosecond laser writing. Optical backscatter reflectometry has been used to study the origin of the optical losses. A detailed study of the laser writing process in thin glass is also presented to facilitate a repeatable wave-guide inscription recipe. (C) 2016 Optical Society of America
Nanoscale lasers are ideal light-signal sources for integrated photonic devices. Most of the present lasers made of dielectric materials are restricted to being larger than half the wavelength of the optical field. Pl...
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Nanoscale lasers are ideal light-signal sources for integrated photonic devices. Most of the present lasers made of dielectric materials are restricted to being larger than half the wavelength of the optical field. Plasmon lasers made from metallic nanostructures can help to break the diffraction limit, yet they suffer from low optical pump efficiencies and low quality factors. Integrating dielectric lasers with plasmonic waveguides to construct hybrid material systems may circumvent these problems and combine the advantages of the two components. Here we demonstrate the nanoscale output of dielectric lasers via photon-plasmon coupling in rationally designed perovskite/silver heterostructures. The perovskite crystals offer the gain and high-Q cavity for low-threshold laser generation, while the embedded silver nanowires (AgNWs) help to output the lasing modes efficiently in the form of surface plasmons. The output coupling can be modulated by controlling the resonant modes of the two-dimensional perovskite microcavities. The results would pave an alternative avenue to ultrasmall light sources as well as fundamental studies of light-matter interactions.
We propose an improved version of the symmetric metal slot waveguides with a Kerr-type nonlinear dielectric core adding linear dielectric buffer layers between the metal regions and the core. Using a finite element me...
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We propose an improved version of the symmetric metal slot waveguides with a Kerr-type nonlinear dielectric core adding linear dielectric buffer layers between the metal regions and the core. Using a finite element method to compute the stationary nonlinear modes, we provide the full phase diagrams of its main transverse magnetic modes as a function of the total power, buffer layer, and core thicknesses that are more complex than the ones of the simple nonlinear metal slot. We show that these modes can exhibit spatial transitions toward specific modes of the new structure as a function of power. We also demonstrate that, for the main modes, the losses are reduced compared to the previous structures, and that they can now decrease with power. Finally, we describe the stability properties of the main stationary solutions using nonlinear FDTD simulations. (C) 2016 Optical Society of America
Subwavelength gratings (SWG) are photonic structures with a period small enough to suppress diffraction, thereby acting as artificial dielectric materials, also called all-dielectric metamaterials. This property has b...
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Subwavelength gratings (SWG) are photonic structures with a period small enough to suppress diffraction, thereby acting as artificial dielectric materials, also called all-dielectric metamaterials. This property has been exploited in many high-performance photonic integrated devices in the silicon-on-insulator (SOI) platform. While SWG waveguides are theoretically lossless, they may exhibit leakage penalty to the substrate due to a combination of reduced modal confinement and finite thickness of the buried oxide (BOX) layer. In this Letter, for the first time, to the best of our knowledge, we analyze substrate leakage losses in SWG waveguides. We establish a direct relation between the effective index of the waveguide mode and the leakage losses which, remarkably, is independent of the geometric parameters of the SWG waveguide. This universal relation is demonstrated both numerically and experimentally, and it provides practical design guidelines to mitigate leakage losses. For BOX thicknesses of 2 and 3 mu m, we find negligible leakage losses when the mode effective index is higher than 1.65 and 1.55, respectively. (C) 2016 Optical Society of America
Visible reconfigurable waveguides were evidenced in a composite system formed with indium-tin-oxide (ITO) films coated on iron-doped lithium noibate (LN) slabs. Surface plasmon polaritions (SPPs) excited at the ITO/LN...
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Visible reconfigurable waveguides were evidenced in a composite system formed with indium-tin-oxide (ITO) films coated on iron-doped lithium noibate (LN) slabs. Surface plasmon polaritions (SPPs) excited at the ITO/LN interface were believed to be behind the observed light guiding, which is inherent with superlow loss for its sub-nanometer modified layer. The forward near-surface-normal scattering and accompanying reduction of the specular reflectivity in the front ITO/LN interface are consistent with SPP excitation. (C) 2016 Optical Society of America
AlGaAs is a promising material for integrated nonlinear photonics due to its intrinsic high nonlinearity. However, the challenging fabrication of deep etched AlGaAs devices makes it difficult to realize high-performan...
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AlGaAs is a promising material for integrated nonlinear photonics due to its intrinsic high nonlinearity. However, the challenging fabrication of deep etched AlGaAs devices makes it difficult to realize high-performance devices such as low-loss dispersion engineered waveguides and high-quality microring resonators. Here, we report a process to make high-quality AlGaAs-on-insulator (AlGaAsOI) wafers where high confinement waveguides can be realized. Using optimized patterning processes, we fabricated AlGaAsOI waveguides with propagation losses as low as 1 dB/cm and microring resonators with quality factors up to 350,000 at telecom wavelengths. Our demonstration opens new prospects for AlGaAs devices in integrated nonlinear photonics. (C) 2016 Optical Society of America
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