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- 2019
- Photovoltaics
- Finite-difference
- Nanotechnology
- Absorption enhancement
- Plasmonics
- Time domain simulation
- Localized surface plasmon resonance
- Optoelectronic Information Materials and Devices
- Islamic Azad University
- Aerospace Research Institute
- Tehran University
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[IEEE 2018 18th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM) - Waterloo, ON (2018.8.19-2018.8.22)] 2018 18th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM) - Plasmon Excitation and Transition Radiation in Graphene Traversed by a Fast Charged Particle
摘要： A progress report is presented on recent theoretical investigations of the interaction of fast charged particles with single and multiple graphene layers. By adopting a fully relativistic formulation of the problem, special focus is placed on retardation effects in the energy loss of a charged particle due to electronic excitations in graphene, which include its plasmon polariton modes, as well as the energy that is emitted from graphene in the form of transition radiation. Using both empirical and ab initio models for the dynamic in-plane conductivity of graphene allows the exploration of energy losses at frequencies ranging from the terahertz to the ultraviolet.
关键词： transition radiation,electron energy loss,graphene,relativistic effects,plasmon polariton
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - Chengdu (2018.3.26-2018.3.28)] 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - Beam-Scanning Antenna Excited by Planar Spoof Surface Plasmon Polaritons
摘要： a wide-angle frequency-controlled beam-scanning antenna excited by planar spoof surface plasmon polaritons (SPPs) is proposed in this paper. The scanning angle and the gains of the proposed antenna can reach 83 degrees and 11.5dBi, respectively. The features of high gain, planar structure and wide scanning angle make this kind of antennas have great values in integrated communication systems.
关键词： antenna,beam-scanning,spoof surface plasmon polaritons (SPPs)
更新于2025-09-23 15:23:52
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Direct Imaging of Surface Plasmon-Driven Hot Electron Flux on the Au Nanoprism/TiO <sub/>2</sub>
摘要： Direct measurement of hot electron flux from a plasmonic Schottky nanodiode is important for obtaining fundamental insights explaining the mechanism for electronic excitation on a surface. Here, we report the measurement of photo-induced hot electrons on a triangular Au nanoprism on TiO2 under incident light with photoconductive atomic force microscopy (pc-AFM), which is direct proof of the intrinsic relation between hot electrons and localized surface plasmon resonance. We find that the local photocurrent measured on the boundary of the Au nanoprism is higher than that inside the Au nanoprism, indicating that field confinement at the boundary of the Au nanoprism acts as a hot spot, leading to the enhancement of hot electron flow at the boundary. Under incident illumination with a wavelength near the absorption peak (645 nm) of a single Au nanoprism, localized surface plasmon resonance resulted in the generation of a higher photo-induced hot electron flow for the Au nanoprism/TiO2, compared with that at a wavelength of 532 nm. We show that the application of a reverse bias results in a higher photocurrent for the Au nanoprism/TiO2, which is associated with a lowering of the Schottky barrier height caused by the image force. These nanoscale measurements of hot electron flux with pc-AFM indicate efficient photon energy transfer mediated by surface plasmons in hot electron-based energy conversion.
关键词： hot electron,Photoconductive atomic force microscopy,localized surface plasmon resonance,Schottky diode,field confinement,Au nanoprism
更新于2025-09-23 15:23:52
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Rejection of Spoof SPPs Using the Second Resonant Mode of Vertical Split-Ring Resonator
摘要： In this letter, the studies of the vertical split-ring resonator (VSRR) at its second resonant mode are carried out for the first time. The VSRR can be regarded as an electric resonator at such resonant mode, which is proven by its resonant current distribution. Then, a new type of rejection plasmonic filter is constructed by adding the VSRR on the planar spoof surface plasmon polariton (SPP) waveguide using double-side corrugated metallic strips. The second resonance of the VSRR is excited by the z-component of the electric field of the spoof SPP mode, near which the SPP propagation is prevented. Utilizing this principle, a plasmonic filter with broadband rejection is designed and fabricated. The measurement result is presented to confirm the highly efficient filtering performance of the proposed filter, which makes it possible to be applied in the advanced integrated plasmonic devices and circuits at microwave and terahertz frequencies.
关键词： vertical split-ring resonator (VSRR),Rejection plasmonic filter,spoof surface plasmon polaritons (SPPs)
更新于2025-09-23 15:22:29
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Narrowband and Full-Angle Refractive Index Sensor Based on a Planar Multilayer Structure
摘要： This work reports a design of a narrowband and full-angle refractive index sensor based on Tamm plasmon resonance (TPR) by introducing a distributed Bragg reflector (DBR) integrated with a non-adjacent metal layer. The analyte flows into the cavity comprising of the DBR and the non-adjacent metal layer. Simulated results show that the incident light can be strongly confined in the specially designed cavity. The sharp reflection dip within the forbidden band of the isolated DBR indicates the excitation of Tamm mode, and the spectral characteristics were monitored upon exposure to various analytes with different refractive indices. The optimally designed system shows the sensitivity (S) and full width at half-maximum (FWHM) can be up to 860 nm/RIU (refractive index unit) and ~2.2 nm with a figure of merit (FOM) of 391. Furthermore, the highly-sensitive characteristic can be sustained in a wide angle range of 0° to almost 90° under both TM- and TE-polarized lights.
关键词： sensitivity,refractive index sensor,Tamm plasmon resonance,figure of merit
更新于2025-09-23 15:22:29
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Reflective SPR Sensor for Simultaneous Measurement of Nitrate Concentration and Temperature
摘要： In this paper, a reflective fiber optic sensor based on surface plasmon resonance (SPR) was proposed to measure nitrate concentration and temperature simultaneously. The sensor adopted reflective structure, and used gold film as metal film for exciting SPR. Then, Cu-nanoparticles/carbon nanotubes composite film was used as sensitive material to measure nitrate concentration, and it was coated on the surface of the gold film by the dip coating method. Finally, polydimethylsiloxane was coated on part of the sensing probe to produce two independent resonance dips in the output spectrum. When the nitrate concentration and temperature changed, the two resonance dips would all move, but with different sensitivities. By monitoring the wavelength shifts of the two dips, the nitrate concentration and temperature could be measured simultaneously with using the dual-wavelength matrix method. Experimental results demonstrated that the measurement sensitivity of the nitrate concentration could reach 3.25 nm/lg[M], and the temperature measurement sensitivity was ?2.02 nm/°C. Moreover, the sensor had high-mechanical strength and was easy to package, which could be applied to remote measurement field.
关键词： reflective surface plasmon resonance (SPR),optical fiber sensor,Nitrate concentration,simultaneous measurement,temperature
更新于2025-09-23 15:22:29
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Investigation of a low cost tapered plastic fiber optic biosensor based on manipulation of colloidal gold nanoparticles
摘要： We demonstrate a low cost Tapered Fiber Optic Biosensor (TFOBS) based on manipulation of colloidal gold nanoparticle in the evanescent field of tapered fiber. The sensor consists of a biconical tapered plastic optical fiber with colloidal gold nanoparticles coated on the tapered region. The strength of evanescent field absorption as a function of gold nanoparticle size is evaluated using Finite Difference Time Domain simulation. Simulation results suggest that in order to achieve maximum absorption in visible range of wavelength, the size of the gold nanoparticle should be in the range 3-4 nm. Gold nanoparticle of desired size is then synthesized and coated on the tapered region to fabricate a TFOBS. It is found experimentally that coating of gold nanoparticles enhances the fraction of light coming out to the cladding surface. This is explained as a consequence of local surface plasmonic resonance. The TFOBS is then tested for its sensing application to detect Bovine Serum Albumin. Level of detection of the proposed sensor is calculated and is found as 0.326gm/dL.As normal albumin level in healthy human blood serum is between 3.5 to 5.5gm/dL, the proposed TFOBS can be used as a low cost accurate albumin sensor.
关键词： Tapered Fiber Optic Sensor,Local Surface Plasmon Resonance,Manipulation of nanoparticle
更新于2025-09-23 15:22:29
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Novel SPR sensing platform based on superstructure MoS2 nanosheets for ultrasensitive detection of mercury ion
摘要： Water contamination by Hg2+ and its detection have attracted much attention. However, the detection limit for Hg2+ by traditional techniques is 200 pM, which is far higher than the maximum Hg2+ concentration allowed in effluent (7.5 pM). Here, we developed a novel surface-plasmon-resonance (SPR) sensor for Hg2+ detection by using superstructure MoS2 nanosheets as the sensing layer material. The simulations and structural characterizations reveal that the ultra-high sensitivity of the SPR sensor arises from the large interlayer spacing and sufficient unsaturated bonds in MoS2 superstructure, which promotes transporting and adsorbing Hg2+. Surprisingly, the Hg2+ detection limit of the SPR sensor is as low as 1.0 pM, which is 200 times lower than those of existing Hg2+ sensors. Therefore, our research presents an effective method for detecting ultra-low concentration of Hg2+ and also reveals the sensing mechanism of MoS2 – based SPR sensor. This not only extends the application of superstructure MoS2 nanosheets, but also provides a novel design idea for the development of ultra-sensitive detection technologies.
关键词： surface plasmon resonance,biosensor,superstructure,MoS2,mercury
更新于2025-09-23 15:22:29
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Metallic Nanostructures for Multispectral Filters
摘要： A metal-dielectric-metal structure with cross-shaped-hole array in metal thin films is studied for plasmonic multispectral filters, which covers visible to near-infrared wavelengths. Surface plasmons are induced from incident wave by a periodic array of nanostructures, then the localized surface plasmon polaritons oscillate in the cavity, which is formed by the two layers of metals through near-field excitation. The transmission spectrum of the metal-dielectric-metal structure with cross-shaped-hole array is investigated with the finite-difference time-domain method; our simulations show that the features of the hole, and the refractive index and the thickness of the dielectric layer all affect the optical spectral performance. This metal-dielectric-metal structure provides additional flexibility in tuning transmission spectrum due to its Fabry-Perot cavity property. Our study shows that it is possible to obtain desired multispectral filters by programming the refractive index and thickness of the dielectric layer, and these parameters of the metallic structures.
关键词： Surface Plasmon,Metallic Nanostructures,Multispectral Filters
更新于2025-09-23 15:22:29
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Scanning Surface Plasmon Microscope for Sensing Lipid Array and Au Film Defect
摘要： We demonstrated a scanning radially-polarized surface plasmon microscopy (SSPM) with submicron lateral resolution and high refractive index sensitivity. According to the captured images, SSPM could be used to verify the quality of deposited Au film and Au structure on surface plasmon sensing chip. The defect on the SPR chip, which disturbed the plasmonic wave around the focal point, could be easily detected by our system. Moreover, the application of SSPM in imaging lipid array was showed in this article. The 1, 2-Dioleoyl-sn-glycero-3-phosphocholine (DOPC) array was made by dip-pen nanolithography. The results indicated that SSPM system could be used in comparing the thickness of DOPC array. Because of the high sensitivity and high spatial resolution of the system, we expected the SSPM to be used in measuring the properties of nanogold array structures and apply to digital-array biosensors in nanoscale.
关键词： 1,2-Dioleoyl-sn-glycero-3-phosphocholine,Scanning surface plasmon microscope,lipid array,nanostructure
更新于2025-09-23 15:22:29