- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Numerical simulation on terahertz wave propagation in plasma channels
摘要： Terahertz (THz) wave generated by femtosecond laser ?lamentation can spatially constrained inside the plasma channels. Our simulation results show that this constraint to THz wave will gradually weaken with the increasing THz frequency. At the same time, results also indicate that the higher plasma density possesses the stronger constraint. In addition, the model ?eld radius and width of THz wave will become larger with the increasing plasma channel radius. Based on the simulation results we ?nd the changes of refractive index at THz wave play an important role on THz wave propagation in plasma channels.
关键词： Plasma channel,Waveguiding,Terahertz wave propagation
更新于2025-09-23 15:23:52
-
[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) - Antiresonant Oxide Island as a Measure for Improved Single-Mode Emission in VCSELs
摘要： In this paper, we propose a novel ARROW VCSEL structure with an antiresonant oxide island placed inside the resonant cavity with the use of planar oxidation technique. The oxidized island does not only improve single-mode emission, which is one of the most desired effects in vertical-cavity surface-emitting lasers (VCSELs), but also has a strong impact on modal loss associated with each lateral mode and affects the shape of their profiles. In this work, we investigate the physical basis of this impact and show how the dimensions of oxidized island determine optical properties of the ARROW VCSEL, leading to the strongest modal discrimination.
关键词： optical modeling,oxidation,ARROW,VCSEL,antiresonance,waveguiding
更新于2025-09-23 15:23:52
-
Selfa??assembled Helical Arrays for Stabilizing the Triplet State
摘要： Room-temperature phosphorescence of metal and heavy atom-free organic molecules has emerged as an area of great potential in the recent past. A rational design played a critical role in controlling the molecular ordering to impart efficient intersystem crossing and stabilize the triplet state to achieve room-temperature ultralong phosphorescence. However, in most of the cases, the strategies followed to strengthen phosphorescence efficiency have resulted in a reduced lifetime, and the available nearly degenerate singlet-triplet energy levels impart a natural competition between delayed fluorescence and phosphorescence, with former one having the advantage. Here, an organic helical assembly supports it towards phosphorescence in this competitive pathway to exhibit an ultralong phosphorescence lifetime. In contrary to other molecules, 3,6-phenylmethanone functionalized 9-hexylcarbazole exhibits a remarkable improvement in phosphorescence lifetime (> 4.1 sec) and quantum yield (11 %) due to an efficient molecular packing in the crystal state. A right-handed helical molecular array act as a trap and exhibits triplet exciton migration to support the exceptionally longer phosphorescence lifetime. The present work will urge new molecular designs to achieve ultralong organic phosphorescence under ambient conditions.
关键词： ultralong phosphorescence,phenylmethanone,carbazole,waveguiding,helicity
更新于2025-09-23 15:21:01
-
Tunable multimodal magnetoplasmonic metasurfaces
摘要： The spectrally controllable enhancement of the transverse magneto-optical Kerr effect is realized in 2D hybrid metal-dielectric magnetoplasmonic metasurfaces. The light diffracted at different interfaces allows one to manipulate light phase in the condition of plasmonic and waveguiding resonance excitation controllable via the azimuthal angle. The multimodal nature of the system provides the flexible tunability of its magneto-optical response.
关键词： azimuthal angle,magneto-optical Kerr effect,magnetoplasmonic metasurfaces,plasmonic resonance,waveguiding resonance
更新于2025-09-16 10:30:52
-
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
-
Topological properties of bound states in the continuum in geometries with broken anisotropy symmetry
摘要： Waveguiding structures made of anisotropic media support bound states in the continuum (BICs) that arise when the radiation channel of otherwise semileaky modes is suppressed. Hitherto, only structures with optical axes aligned in symmetric orientations inside the waveguide plane, where BICs appear as lines in the momentum-frequency dispersion diagram, have been considered. Here we address settings where such symmetry is broken and unveil a number of fundamental different features. Weak and strong symmetry-breaking regimes are identified, corresponding to azimuthal and polar optical axes orientation asymmetries, respectively. The azimuthal symmetry breaking is found to still preserve the existence loci of BICs in the momentum-frequency dispersion diagram as lines. However, all possible BICs become interferometric, while the polarization separable states that occur in symmetric settings cease to exist. The polar symmetry breaking has stronger effects and transforms the BICs’ existence loci from lines to points, which correspond to full-vector states that exist at discrete values of the optical axis orientation for a given wavelength. Such transformation results in fundamental changes in the topological properties of the radiated field around the BICs.
关键词： anisotropic media,bound states in the continuum,topological properties,symmetry breaking,waveguiding structures
更新于2025-09-04 15:30:14
-
Controlling light in Airy and higher-order caustic photonic structures
摘要： Caustics form geometrically stable structures in light and are hierarchically categorized by the catastrophe theory. We embed higher-order cusp and swallowtail catastrophes in paraxial beams and investigate their dynamics. Utilizing high-intensity caustics that propagate on curved trajectories, we realize photonic caustic lattices in photosensitive media, and demonstrate waveguiding with a rich diversity of light guiding paths.
关键词： caustics,photonic structures,waveguiding,catastrophe theory,nonlinear photonics
更新于2025-09-04 15:30:14