scholarly journals Angstrom-Scale Active Width Control of Nano Slits for Variable Plasmonic Cavity

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2463
Author(s):  
Dukhyung Lee ◽  
Dohee Lee ◽  
Hyeong Seok Yun ◽  
Dai-Sik Kim

Nanogap slits can operate as a plasmonic Fabry–Perot cavity in the visible and infrared ranges due to the gap plasmon with an increased wavenumber. Although the properties of gap plasmon are highly dependent on the gap width, active width tuning of the plasmonic cavity over the wafer length scale was barely realized. Recently, the fabrication of nanogap slits on a flexible substrate was demonstrated to show that the width can be adjusted by bending the flexible substrate. In this work, by conducting finite element method (FEM) simulation, we investigated the structural deformation of nanogap slit arrays on an outer bent polydimethylsiloxane (PDMS) substrate and the change of the optical properties. We found that the tensile deformation is concentrated in the vicinity of the gap bottom to widen the gap width proportionally to the substrate curvature. The width widening leads to resonance blueshift and field enhancement decrease. Displacement ratio ((width change)/(supporting stage translation)), which was identified to be proportional to the substrate thickness and slit period, is on the order of 10−5 enabling angstrom-scale width control. This low displacement ratio comparable to a mechanically controllable break junction highlights the great potential of nanogap slit structures on a flexible substrate, particularly in quantum plasmonics.

2018 ◽  
Vol 101 (6) ◽  
pp. 48-57 ◽  
Author(s):  
Muneaki Kurimoto ◽  
Hiroya Ozaki ◽  
Tooru Sawada ◽  
Toshihisa Funabashi ◽  
Takeyoshi Kato ◽  
...  

2014 ◽  
Vol 1 ◽  
pp. 2 ◽  
Author(s):  
Cheng-Ping Huang ◽  
Che-Ting Chan

Confinement of light by subwavelength objects facilitates the realization of compact photonic devices and the enhancement of light-matter interactions. The Fabry-Perot (FP) cavity provides an efficient tool for confining light. However, the conventional FP cavity length is usually comparable to or larger than the light wavelength, making them inconvenient for many applications. By manipulating the reflection phase at the cavity boundaries, the FP cavity length could be made much smaller than the wavelength. In this review, we consider the subwavelength FP resonance in a plasmonic system composed of a slit grating backed with a ground plane, covering the spectral range from microwave to THz and infrared regime. For very narrow slit width and spacer thickness, a typical zero-order and deep subwavelength FP resonance in the metallic slits can be strongly induced. Moreover, due to the subwavelength FP resonance, greatly enhanced electromagnetic pressure can also be induced in the system. The sign and magnitude of the electromagnetic pressure are dominated by the field penetration effect in the metal as well as the field enhancement in the FP cavities. The effect promises a variety of potential applications, such as detecting tiny motions and driving the mechanical oscillations.


2020 ◽  
Vol 44 (2) ◽  
pp. 219-228
Author(s):  
D.V. Nesterenko

The resonance characteristics of the Fabry-Pérot resonator modes supported by metal/dielectric/metal planar structures are studied in the case of absorbing media for near-to-normal light incidence. Approximations based on rigorous solution and field-transfer model for the field and resonance line shapes in spectra are attributed to the class of Fano and Lorentz resonances. The analytical expressions are obtained for the propagation constant and field enhancement of the mode, width, height and slope of resonance line shapes in spectra as functions of structural parameters. With estimation of field characteristics of the fabricated loss structures based on aluminum and quartz, the peaks in the transmission spectra can be attributed to the excitation of Fabry-Pérot modes. Fundamental characterization of Fabry-Pérot resonances may find applications in optical processing and sensing.


Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 619 ◽  
Author(s):  
Junhua Tong ◽  
Songtao Li ◽  
Chao Chen ◽  
Yulan Fu ◽  
Fengzhao Cao ◽  
...  

A random laser was achieved in a polymer membrane with silver nanoflowers on a flexible substrate. The strong confinement of the polymer waveguide and the localized field enhancement of silver nanoflowers were essential for the low-threshold random lasing action. The lasing wavelength can be tuned by bending the flexible substrate. The solution phase synthesis of the silver nanoflowers enables easy realization of this type of random lasers. The flexible and high-efficiency random lasers provide favorable factors for the development of imaging and sensing devices.


2015 ◽  
Vol 1109 ◽  
pp. 505-508
Author(s):  
J. Rouhi ◽  
F.S. Husairi ◽  
Kevin Alvin Eswar ◽  
M.H. Mamat ◽  
Salman A.H. Alrokayan ◽  
...  

A simple method for fabricating lateral Si diodes with various gap widths were designed using the special properties of anisotropic TMAH wet etching and local anodic oxidation. The electrical performance of lateral diode was characterized using an HP4156c semiconductor parameter analyzer (SPA300HV, Agilent) at room temperature in a vacuum environment lower than 10-8Torr. The emission current from the silicon emitter cathode was measured as a function of the applied anode voltage. The effect of changing the anode-cathode gap was observed in the I-V characteristics, with a distinct reduction in the device turn-on with a decrease in the gap. For narrowed nanogaps from 55 nm to 35 nm, the turn-on voltage was decreased from 21 V to 16 V. Values of field enhancement factor β and emitting area A for different gap width were measured using Fowler-Nordheim plot. Our results indicate that β reduces and emitting area increases with increasing of gap width.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Isa Kocakarin ◽  
Korkut Yegin

Surface plasmon-enhanced gold nanoantenna structures on glass substrate are studied for increased localized electric field and fluorescence at the feed gap locations of the antennas. Dipole, Archimedean balanced spiral, and bowtie and double bowtie geometries are studied for surface plasmon effect. Different flare angles for bowtie geometries are compared to each other. Double bowtie geometry with dual polarization capability exhibited superior performance with almost 56 dB field enhancement factor. We also studied the effect of substrate thickness on electric field enhancement and we found that glass thickness plays a critical role for coherent addition of surface plasmons at the feed gap location. The surface plasmon effect is proven by considering perfect electric conductor model of gold instead of its modified Drude model.


Author(s):  
Yunjie Shi ◽  
Yuming Dong ◽  
Degui Sun ◽  
Guangyuan Li

Metal nanoparticles supporting plasmons are widely used to enhance electromagnetic fields, resulting in strong light-matter interactions at the nanoscale in a diverse range of applications. Recently, it has been shown that when metal nanorods are periodically arranged with proper lattice periods, surface lattice resonances (SLRs) can be excited and near fields can be greatly enhanced over extended volumes. In this work, we report significant near field enhancement over even larger volumes by placing the metal nanorod array within a Fabry-Pérot (F-P) microcavity. Results show that taking advantage of strong coupling between the SLR and the photonic F-P resonances, the electric field intensity of the bonding split mode can be enhanced by up to 1935 times, which is about three times of the enhancement of the SLR, and the greatly enhanced field can extend over most of the F-P microcavity. We further show that the F-P resonances of both odd and even orders can strongly couple to the SLR by varying the nanorods position from the middle of the microcavity. We expect that the proposed plasmonic-photonic coupling system will find promising applications in nanolasers, nonlinear optics and sensing.


Nano Research ◽  
2014 ◽  
Vol 7 (8) ◽  
pp. 1146-1153 ◽  
Author(s):  
Shermin Arab ◽  
P. Duke Anderson ◽  
Maoqing Yao ◽  
Chongwu Zhou ◽  
P. Daniel Dapkus ◽  
...  

Author(s):  
J. W. Fang ◽  
Z. Sun ◽  
Y. R. Zhang

Abstract. A method integrating terrestrial laser scanning (TLS) and finite element modelling (FEM) is proposed in this study. It aims at assessing the structural deformation of a historic brick-masonry building, the Beamless Hall at Linggu Temple in Nanjing, China. The building was composed of a series of vaults and arches, the largest among whom spans over 11m. TLS (Z+F Imager5010X) was used to collect 3D point cloud with high density. Point slices and geometric feature computation (verticality) were employed to detect geometric displacement quantitatively and intuitively. FEM-simulation was based on an ideal 3D model ignoring geometric anomalies. Results show that the Beamless Hall has inherent structural defect owing to its asymmetric layout along the transverse axis. Computing geometric feature of point cloud is fast and intuitive to detect and show geometric deviation. Inferred by FEM-simulated results and TLS-based deviation analysis, the building’s asymmetrical layout under self-weight is probably the main reason causing its structural deformation. Further developments include FEM based on as-built geometry, corrected materials parameters, and a comprehensive geometric deviation analysis.


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