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 共查询到20条相似文献,搜索用时 0 毫秒
1.
Wang  Jin  Yang  Guofeng  Ye  Xuanchao  Zhang  Qing  Gao  Shumei  Chen  Guoqing 《Plasmonics (Norwell, Mass.)》2017,12(5):1641-1647
Plasmonics - We theoretically explore the appearances and characteristics of Fano resonances in novel-designed nanobelt cluster, which shows strong modulation depths, and the Fano dips can be...  相似文献   

2.
Li  Yuan  Huo  Yiping  Zhang  Ying  Zhang  Zhongyue 《Plasmonics (Norwell, Mass.)》2017,12(5):1613-1619
Plasmonics - The plasmon resonances and field enhancement in split ring-perfect ring (SR-PR) nanostructure are investigated numerically by using a finite element method. Multiple electric...  相似文献   

3.
We proposed a plasmonic nanosensor with an ultra-high sensitivity based on groove and ring resonator. Simulation results show that these sharp Fano profiles originate from the interference between the groove and ring resonator. The profile can be easily tuned by changing the parameters of the structure. Moreover, we introduce a new way to achieve multiple Fano resonances through independent processes by adding a side-coupled stub cavity, and the Fano resonances can be tuned independently. These characteristics offer flexibility in the design of the devices. This nanosensor yields an ultra-high sensitivity of ~2000 nm/RIU, which is rarely seen in the previous report. Our structures may have potential applications for nanosensors, slow light, and nonlinear devices in highly integrated circuits.  相似文献   

4.
Plasmonic Fano resonances arise in symmetric single-layer conical nanoshells, which can be switched on and off by changing the polarization of the incident electric field. By breaking the symmetry, higher-order dark hybridized modes emerge in the spectrum, which couple to the superradiant bright mode and induce higher-order plasmonic Fano resonances. From a comparison with spherical nanostructures, it comes out that single-layer conical nanoshells are found to be highly capable in the generation of higher-order Fano resonances with larger modulation depths in the optical spectra. Such nanostructures are also found to offer high values of figure of merit and contrast ratio due to which they are highly suitable for biological sensors.  相似文献   

5.
Zhou  Chen  Huo  Yiping  Guo  Yiyuan  Niu  Qiqiang 《Plasmonics (Norwell, Mass.)》2021,16(5):1735-1743
Plasmonics - A metal-insulator-metal (MIM) waveguide consisting of two stub resonators and a ring resonator is proposed, which can be used as refractive index sensor and stop-band filter at the...  相似文献   

6.
Huang  Yu  Ma  Lingwei  Hou  Mengjing  Zhang  Zhengjun 《Plasmonics (Norwell, Mass.)》2016,11(5):1377-1383
Plasmonics - We have demonstrated directly that the physical origin of Fano resonances in two-dimensional (2D) plasmonic crystals (PCs) is a wave-interference phenomenon. This is achieved by...  相似文献   

7.
We theoretically investigate the plasmonic Fano resonance in a triangular nanoprism dimer. By adjusting the geometry parameters, we have observed a Fano line shape in the scattering spectra, which is induced by the competence of bonding and antibonding modes in the triangular nanoprism dimer. The Fano line shape can be well described by a theoretical model of two harmonic oscillators. A figure of merit value as high as 16.1 is achieved in the triangular nanoprism dimer, which is caused by the Fano resonance. The electric field at the corner of the triangular prisms is the highest among the circular cylinder dimer and square rod dimmers, which shows that the triangular prism dimer is more suitable for the detection of biomolecules. The triangular prism dimer may also used in plasmonic circuits.  相似文献   

8.
Fano resonances are numerically predicted in an ultracompact plasmonic structure, comprising a metal-isolator-metal (MIM) waveguide side-coupled with two identical stub resonators. This phenomenon can be well explained by the analytic model and the relative phase analysis based on the scattering matrix theory. In sensing applications, the sensitivity of the proposed structure is about 1.1?×?103 nm/RIU and its figure of merit is as high as 2?×?105 at λ?=?980 nm, which is due to the sharp asymmetric Fano line-shape with an ultra-low transmittance at this wavelength. This plasmonic structure with such high figure of merits and footprints of only about 0.2 μm2 may find important applications in the on-chip nano-sensors.  相似文献   

9.
Zhang  Xingfang  Yan  Xin  Liu  Fengshou  Liang  Lanju 《Plasmonics (Norwell, Mass.)》2021,16(4):1041-1048
Plasmonics - Split theta-shaped nanocavities composed of an elliptical disk embedded in a nonconcentric split ring are theoretically investigated by the finite-difference time-domain method....  相似文献   

10.
In this work, we conceive and demonstrate the magneto-electric double Fano resonances of a hetero-cavity composed of Si disk and Au split ring, where Si disk can provide additional magnetic responses besides electric responses. The interference between electric and magnetic responses in proposed hetero-cavity gives rise to magneto-electric double Fano resonances with magnetic and electric near-field enhancements. Dipole radiative enhancement is used to analyze magnetic and electric responses of hetero-cavity and the spectral features of hetero-cavity can be used to quantitatively characterize by coupled oscillator model. And the spectral tunability of magneto-electric double Fano resonances is investigated, highlighting a potential for applications in low-loss sensing and nanophotonic devices.  相似文献   

11.
Wang  Luwei  Qu  Junle  Song  Jun  Xian  Jinhong 《Plasmonics (Norwell, Mass.)》2017,12(4):1145-1151
Plasmonics - A novel plasmonic nanolaser is proposed based on a heptamer of silver nanoparticles surrounded by gain material. Optical properties of the proposed laser are analyzed using the finite...  相似文献   

12.
A simple T-shaped plasmonic nanostructure composed of two perpendicular coupled nanorods is proposed to produce strong Fano resonances. By the near-field coupling between the “bright” dipole and “dark” quadrupole plasmons of the nanorods, a deep Fano dip is formed in the extinction spectrum, which can be well fitted by the Fano interference model. The effects of the geometry parameters including nanorod length, coupling gap size, and coupling location to the Fano resonances are analyzed in detail, and a very high refractive index sensitivity is achieved by the Fano resonance. Also by adjusting the incident polarization direction, double Fano resonances can be formed by the interferences of the dipole, quadrupole, and hexapole plasmons. The proposed nanorod dimer structure is agile, and a trimer which supports double Fano resonances can be easily formed by introducing a third perpendicular coupled nanorod. The proposed T-shaped nanorod dimer structure may have applications in the fields of biological sensing and plasmon-induced transparency.  相似文献   

13.
Binfeng  Yun  Ruohu  Zhang  Guohua  Hu  Yiping  Cui 《Plasmonics (Norwell, Mass.)》2016,11(4):1157-1162
Plasmonics - A plasmonic waveguide system composed of metal-insulator-metal (MIM) stub coupled with circular cavity resonator was proposed to produce ultra sharp Fano resonances, which resulted...  相似文献   

14.
Optical properties of disk-ring plasmonic nanostructures with double symmetry breaking are investigated theoretically. Tunable higher order Fano resonance is achieved, and it is sensitive to the degree of asymmetry of the nanoring, the offset and the dimension of the nanodisk. It is demonstrated that such higher order Fano resonances originate from the destructive interference between the bright mode of the displaced nanodisk and the dark mode of the asymmetric nanoring. By tunning the asymmetry degree of the nanoring, the offset, and the dimension of the nanodisk, certain higher order Fano resonances can be suppressed or enhanced. Double asymmetry breaking also allows the realization of the stronger electric field enhancement, resulting from the stronger interaction between the displaced nanodisk and the asymmetric nanoring.  相似文献   

15.
Zhou  Hang  Gao  Dongliang  Gao  Lei 《Plasmonics (Norwell, Mass.)》2018,13(2):623-630
Plasmonics - We study the multipolar surface plasmon modes and its link to Fano resonances in bimetallic nanoparticles. General expressions for the multipolar surface plasmon frequencies and...  相似文献   

16.
We report on the numerically and analytically investigated plasmonic and photothermal responses of a nanomatryushka structure composed of silver concentric nanoshells which exhibited strong plasmon resonance localization in the optical frequencies. Illuminating an isolated silver nanomatryushka in an aqueous system, we calculated the photothermal response of the structure and quantified the absorbed optical power and generated photothermal heat. In addition, it is shown that a couple of nanomatryushka structures as a symmetric molecular dimer in weak and strong coupling regimes are able to support strong plasmon resonances in the visible to the near-infrared region. Utilizing strong near-field coupling in the metallic nanostructures and hybridization of plasmons, and also employing silver as a highly absorptive material at the visible spectrum, we increased the energy dissipation per unit volume almost three orders of magnitude in comparison to the other analogous subwavelength structures. Employing numerical methods, we showed that a symmetric metallic nanomatryushka dimer is able to generate enough photothermal heat which could result in a remarkable amount of temperature change (ΔT?=?140 K) at the picosecond time scale. According to hybridization theory, the symmetric dimer is able to support strong bonding and antibonding plasmon resonant modes. Utilizing concentric nanoshells with high geometrical tunability facilitates using all of the surfaces and center of nanoparticles to generate heat with a large temperature change within a short relaxation time. This understanding opens new avenues to utilize simple nanoparticle orientations to generate significant heat power in an extremely short time scale for cancer therapy, photothermal therapy, and biological applications.  相似文献   

17.
Plasmonics - Breaking the morphological and compositional symmetries of metallic nanoparticle (NP) dimers provides a novel approach to modulate plasmon coupling between the NPs. In this study, we...  相似文献   

18.
Plasmonic optical trapping is widely applied in the field of bioscience, microfluidics, and quantum optics. It can play a vital role to extend optical manipulation tools from micrometer to nanometer scale level. Currently, it is a challenge to obtain the highly stable optical trapping with low power and less damage. In this paper, we propose Fano resonance-assisted self-induced back-action (FASIBA) method, through which a single 40-nm gold particle can be trapped in hole-slit nano-aperture milled on metallic film. It is used to achieve ultra-accurate positioning of nanoparticle, metallic nanostructures at wide infrared wavelength range, quite effectively and evidently. The stable plasmonic trapping is achieved by tuning the transmission wavelengths and modifications of nanoslit, indicating that the depth of potential well can be increased from minus 8KT to 12KT, with the input power of 109 W/m2. This can be attributed to great modifications in Fano resonance transmissions according to self-induced back-action (SIBA) theory. The results are basically helpful to facilitate the trapping with lower power and less damage to the objects, which enables new scenario for the treatment of undesirable spread of a single nanoscale creature, such as virus.  相似文献   

19.
This paper proposes a compact plasmonic structure that is composed of a metal-insulator-metal (MIM) waveguide coupled with a groove and stub resonators, and then investigates it by utilizing the finite element method (FEM). Simulation results show that the interaction between the local discrete state caused by the stub resonator and the continuous spectrum caused by the groove resonator gives rise to one of the two Fano resonances, while the generation of the other resonance relies only on the groove. Meanwhile, the asymmetrical linear shape and the resonant wavelength can be easily tuned by changing the parameters of the structure. By adding stubs on the groove, we excited multiple Fano resonances. The proposed structure can serve as an excellent plasmonic sensor with a sensitivity of 2000 nm/RIU and a figure of merit of about 3.04?×?103, which can find extensive applications for nanosensors.  相似文献   

20.
We propose a compact plasmonic structure comprising a metal-dielectric-metal (MDM) waveguide coupled with a side cavity and groove resonators. The proposed system is investigated by the finite element method. Simulation results show that the side-coupled cavity supports a local discrete state and the groove provides a continuous spectrum, the interaction between them, gives rise to the Fano resonance. The asymmetrical line shape and the resonant wavelength can be easily tuned by changing the geometrical parameters of the structure. Moreover, we can extend this plasmonic structure by the double side-coupled cavities to gain the multiple Fano resonances. The proposed structure can serve as an excellent plasmonic sensor with a sensitivity of ~1900 nm/RIU and a figure of merit of about ~3.8?×?104, which can find wide applications for nanosensors.  相似文献   

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