scholarly journals Design of Nanoscale Hybrid Insulator-metal-insulator Plasmonic Waveguide

2021 ◽  
Author(s):  
Pintu Kumar ◽  
D. K. Singh ◽  
Rakesh Ranjan
Keyword(s):  
Electric Field ◽  
Field Enhancement ◽  
Separation Distance ◽  
Plasmonic Waveguide ◽  
Coupling Length ◽  
Localized Surface Plasmon ◽  
Dielectric Waveguides ◽  
Plasmonic Waveguides ◽  
Propagation Length ◽  
Metal Insulator

Abstract Optical properties of the fundamental hybrid mode of hybrid insulator-metal-insulator plasmonic waveguide (HIMIPW), consists of insulator-metal-insulator sandwiched between two dielectric waveguides, have been investigated to achieve the relatively high propagation length and large normalized intensity at 1.55 µm working wavelength. The main aim of the current work is to settle the issues of high power loss and size of waveguide dimension. The optimum waveguide dimension of 0.2 µm × 0.02 µm has been obtained propagation length around 289.26 µm. The normalized intensity in the low-index region of the HIMIPW has been achieved around 67.50 , due to the electric field enhancement in this region. It is beneficial for the design of bio-sensing, optical manipulations, etc. The electric field intensity has been attained highest values at wavelength 1.55 µm for the optimum dimension of the HIMIPW ( = 0.2 µm, and ), due to highly localized surface plasmon resonance at the metal-dielectric interfaces. The investigation of the coupling length between the two identical parallel HIMIPWs with a separation distance has been done. Further to improve the coupling length, a metallic strip has been inserted between them, keeping the separation distance unchanged. The higher coupling length leads to lower crosstalk between two parallel hybrid plasmonic waveguides, which can be highly useful to achieve the larger integration over the photonic chip.

Tuning the Localized Surface Plasmon Resonance of Al-Al2O3 Nanosphere Towards NIR Region by Gold Coating

2020 ◽  
Vol 12 ◽  
Author(s):  
Jyoti Katyal ◽  
Shivani Gautam
Keyword(s):  
Electric Field ◽  
Field Distribution ◽  
Dielectric Layer ◽  
Electric Field Distribution ◽  
Active Material ◽  
Visible Region ◽  
Field Enhancement ◽  
Localized Surface Plasmon ◽  
Sers Substrate ◽  
Al Nanoparticles

Background: A relatively narrow LSPR peak and a strong inter band transition ranging around 800 nm makes Al strongly plasmonic active material. Usually, Al nanoparticles are preferred for UV-plasmonic as the SPR of small size Al nanoparticles locates in deep UV-UV region of the optical spectrum. This paper focused on tuning the LSPR of Al nanostructure towards infrared region by coating Au layer. The proposed structure has Au as outer layer which prevent the further oxidation of Al nanostructure. Methods: The Finite Difference Time Domain (FDTD) and Plasmon Hybridization Theory has been used to evaluated the LSPR and field enhancement of single and dimer Al-Al2O3-Au MDM nanostructure. Results: It is observed that the resonance mode show dependence on the thickness of Al2O3 layer and also on the composition of nanostructure. The Au layered MDM nanostructure shows two peak of equal intensities simultaneously in UV and visible region tuned to NIR region. The extinction spectra and electric field distribution profiles of dimer nanoparticles are compared with monomer to reveal the extent of coupling. The dimer configuration shows higher field enhancement ~107 at 1049 nm. By optimizing the thickness of dielectric layer the MDM nanostructure can be used over UV-visible-NIR region. Conclusion: The LSPR peak shows dependence on the thickness of dielectric layer and also on the composition of nanostructure. It has been observed that optimization of size and thickness of dielectric layer can provide two peaks of equal intensities in UV and Visible region which is advantageous for many applications. The electric field distribution profiles of dimer MDM nanostructure enhanced the field by ~107 in visible and NIR region shows its potential towards SERS substrate. The results of this study will provide valuable information for the optimization of LSPR of Al-Al2O3-Au MDM nanostructure to have high field enhancement.

scholarly journals A Triangle Hybrid Plasmonic Waveguide with Long Propagation Length for Ultradeep Subwavelength Confinement

Crystals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 64
Author(s):  
Qian Zhang ◽  
Jinbin Pan ◽  
Shulong Wang ◽  
Yongqian Du ◽  
Jieyu Wu
Keyword(s):  
Plasmonic Waveguide ◽  
Ohmic Loss ◽  
Plasmonic Waveguides ◽  
Propagation Length ◽  
Silicon Waveguide ◽  
Hybrid Plasmonic Waveguide ◽  
Light Waves ◽  
Fabrication Errors ◽  
Application Fields ◽  
Mode Area

Facing the problems of ohmic loss and short propagation length, the application of plasmonic waveguides is limited. Here, a triangle hybrid plasmonic waveguide is introduced, where a cylinder silicon waveguide is separated from the triangle prism silver waveguide by a nanoscale silica gap. The process of constant optimization of waveguide structure is completed and simulation results indicate that the propagation length could reach a length of 510 μm, and the normalized mode area could reach 0.03 along with a high figure of merit 3150. This implies that longer propagation length could be simultaneously achieved along with relatively ultra-deep subwavelength mode confinement due to the hybridization between metallic plasmon polarization mode and silicon waveguide mode, compared with previous study. By an analysis of fabrication errors, it is confirmed that this waveguide is fairly stable over a wide error range. Additionally, the excellent performance of this is further proved by the comparison with other hybrid plasmonic waveguides. Our work is significant to manipulate light waves at sub-wavelength dimensions and enlarge the application fields, such as light detection and photoelectric sensors, which also benefit the improvement of the integration of optical devices.

scholarly journals Synthesis of Au–Ag Alloy Nanoparticle-Incorporated AgBr Crystals

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 745 ◽  
Author(s):  
Shin-ichi Naya ◽  
Musashi Fujishima ◽  
Hiroaki Tada
Keyword(s):  
Aqueous Solution ◽  
Electric Field ◽  
Silver Halide ◽  
Field Enhancement ◽  
Local Electric Field ◽  
Localized Surface Plasmon ◽  
Light Illumination ◽  
Chemical Transformations ◽  
Electric Field Enhancement ◽  
Local Electric Field Enhancement

Nanoscale composites consisting of silver and silver halide (Ag–AgX, X = Cl, Br, I) have attracted much attention as a novel type of visible-light photocatalyst (the so-called plasmonic photocatalysts), for solar-to-chemical transformations. Support-free Au–Ag alloy nanoparticle-incorporated AgBr crystals (Au–Ag@AgBr) were synthesized by a photochemical method. At the initial step, Au ion-doped AgBr particles were prepared by adding an aqueous solution of AgNO3 to a mixed aqueous solution of KBr and HAuBr4. At the next step, UV-light illumination (λ = 365 nm) of a methanol suspension of the resulting solids yielded Au–Ag alloy nanoparticles with a mean size of approximately 5 nm in the micrometer-sized AgBr crystals. The mole percent of Au to all the Ag in Au–Ag@AgBr was controlled below < 0.16 mol% by the HAuBr4 concentration in the first step. Finite-difference time-domain calculations indicated that the local electric field enhancement factor for the alloy nanoparticle drastically decreases with an increase in the Au content. Also, the peak of the localized surface plasmon resonance shifts towards longer wavelengths with increasing Au content. Au–Ag@AgBr is a highly promising plasmonic photocatalyst for sunlight-driven chemical transformations due to the compatibility of the high local electric field enhancement and sunlight harvesting efficiency.

scholarly journals Propagation Characteristics of Multilayer Hybrid Insulator-Metal-Insulator and Metal-Insulator-Metal Plasmonic Waveguides

2014 ◽  
Vol 2 (3) ◽  
pp. 35 ◽  
Author(s):  
M. Talafi Noghani ◽  
M. H. Vadjed Samiei
Keyword(s):  
Transfer Matrix Method ◽  
Matrix Method ◽  
Slab Waveguide ◽  
Plasmonic Waveguides ◽  
Propagation Characteristics ◽  
Propagation Length ◽  
Metal Insulator ◽  
Slab Waveguides ◽  
Figures Of Merit ◽  
Metal Insulator Metal

Propagation characteristics of symmetrical and asymmetrical multilayer hybrid insulator-metal-insulator (HIMI) and metal-insulator-metal (HMIM) plasmonic slab waveguides are investigated using the transfer matrix method. Propagation length (Lp) and spatial length (Ls) are used as two figures of merit to qualitate the plasmonic waveguides. Symmetrical structures are shown to be more performant (having higher Lp and lower Ls), nevertheless it is shown that usage of asymmetrical geometry could compensate for the performance degradation in practically realized HIMI waveguides with different substrate materials. It is found that HMIM slab waveguide could support almost long-range subdiffraction plasmonic modes at dimensions lower than the spatial length of the HIMI slab waveguide.

Multilayered Nanostructure for Inducing a Large and Tunable Optical Field

2020 ◽  
Vol 10 (6) ◽  
pp. 840-848
Author(s):  
Jyoti Katyal
Keyword(s):  
Electric Field ◽  
Plasmon Resonance ◽  
Dielectric Layer ◽  
Inner Core ◽  
Strong Field ◽  
Fdtd Method ◽  
Wavelength Region ◽  
Field Enhancement ◽  
Surface Enhanced Raman Spectroscopy ◽  
Localized Surface Plasmon

Objective: The localized surface plasmon resonance (LSPR) and field enhancement of multilayered nanostructure over single and dimer configuration is studied using finite difference time domain (FDTD) method. Experimental: In multilayered nanostructure, there exist concentric nanoshells and metallic core which are separated by a dielectric layer. Strong couplings between the core and nanoshell plasmon resonance modes show a shift in LSPR and enhancement in field around nanostructure. The calculation of the electric field enhancement shows a sharp increase in the electric field on the surface of inner core i.e., inside the dielectric layer of Metal-Dielectric-Metal (MDM) structure whereas smaller enhancement on the outer layer of MDM structure is observed. Results: The Au-Air-Au mono MDM nanostructure shows strong near-field enhancement as compared to bare nanosphere in the infrared region, which have potential applications in surfaceenhanced spectroscopy, whereas Al-Air-Al and Ag-Air-Ag shows potential towards lower wavelength region. On coupling the MDM nanostructure forming a dimer configuration the field enhancement factor increases to 10^8. Conclusion: As compared to other nanostructures, MDM nanostructure provides both strong field enhancement and wide wavelength tunability therefore promising for surface enhanced Raman spectroscopy (SERS) applications.

scholarly journals Design of Plasmonic NOT Logic Gate Based on Insulator – Metal – Insulator (IMI) waveguides

2020 ◽  
Vol 9 (1) ◽  
pp. 91-94
Author(s):  
H. F. Fakhruldeen ◽  
T. S. Mansour
Keyword(s):  
Dielectric Material ◽  
Logic Gate ◽  
Incident Light ◽  
Contrast Ratio ◽  
Optical Signal ◽  
Limit Problem ◽  
Dielectric Waveguides ◽  
Plasmonic Waveguides ◽  
Metal Insulator ◽  
All Optical

   In this work, all-optical plasmonic NOT logic gate was proposed using Insulator-Metal-Insulator (IMI) plasmonic waveguides Technology. The proposed all-optical NOT gate is simulated and realized using COMSOL Multiphysics 5.3a software. Recently, plasmonic technology has attracted high attention due to its wide applications in all-optical signal processing. Due to its highly localization to metallic surfaces, surface plasmon (SP) may have huge applications in sub wavelength to guide the optical signal in the waveguides which results in overcoming the diffraction limit problem in conventional optics. The proposed IMI structure is consist of a dielectric waveguides plus metallic claddings, which guide the incident light strongly in the insulator region. Our design consists of symmetric nano-rings structures with two straight waveguides which based on IMI structure. The operation of all-optical NOT gate is realized by employing the constructive and destructive interface between the straight waveguides and the nano-rings structure waveguides. There are three ports in the proposed design, input, control and output ports. The activation of control port is always ON. By changing the structure dimensions, the materials, the phase of the applied optical signal to the input and control ports, the optical transmission at the output port is changed. In our proposed structure, the insulator dielectric material is glass and the metal material is silver. The calculated contrast ratio between (ON and OFF) output states is 3.16 (dB).

scholarly journals Optically Induced Field-Emission Source Based on Aligned Vertical Carbon Nanotube Arrays

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1810
Author(s):  
Mengjie Li ◽  
Qilong Wang ◽  
Ji Xu ◽  
Jian Zhang ◽  
Zhiyang Qi ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Electric Field ◽  
Field Emission ◽  
Field Enhancement ◽  
Absorption Efficiency ◽  
Photon Absorption ◽  
Nanotube Arrays ◽  
Carbon Nanotube Arrays ◽  
Induced Field ◽  
Optically Induced

Due to the high field enhancement factor and photon-absorption efficiency, carbon nanotubes (CNTs) have been widely used in optically induced field-emission as a cathode. Here, we report vertical carbon nanotube arrays (VCNTAs) that performed as high-density electron sources. A combination of high applied electric field and laser illumination made it possible to modulate the emission with laser pulses. When the bias electric field and laser power density increased, the emission process is sensitive to a power law of the laser intensity, which supports the emission mechanism of optically induced field emission followed by over-the-barrier emission. Furthermore, we determine a polarization dependence that exhibits a cosine behavior, which verifies the high possibility of optically induced field emission.

Sign in / Sign up

Export Citation Format

Share Document