scholarly journals Plasmonic Nanosensor Based on Mie Scattering in Multi-mode Metallic Nanoparticles

2021 ◽  
Author(s):  
jun zhu ◽  
Yihong Ren
Keyword(s):  
Refractive Index ◽  
Metallic Nanoparticles ◽  
Structural Parameters ◽  
Mie Scattering ◽  
Absorption Efficiency ◽  
Spherical Particles ◽  
Light Extinction ◽  
Refractive Index Sensor ◽  
Refractive Index Sensitivity ◽  
Multi Mode

Abstract The scattering and absorption characteristics of light by spherical particles are often analysed based on the classical Mie scattering theory.In this paper，we study refractive index sensor of multi-mode based on the Mie scattering and its extension theories. Based on the Mie scattering theory, the light extinction, scattering, absorption cross-section, and absorption efficiency associated with the spherical particle can be calculated.The structure that we design has a long wavelength possesses a higher power than that with a short wavelength.Also,the structural parameters induces a red-shift in the resonance spectrum. Lastly,the results of multi-mode are obtained: the transmittance of modes 1, 2, and 3 vary within the ranges 0.43–0.67, 0.61–0.46, and 0.26–0.5, respectively; the figures of merit of modes 1, 2, and 3 can reach as high as 12, 27.7, and 3.8, respectively; the refractive index sensitivity can reach as high as and . As indicated by these findings, the proposed structure can significantly improve the transmission characteristics of nanodevices. Such a structure holds significant potential for application in the field of on-chip plasma sensing and optical communication.

scholarly journals Narrowband Perfect Absorber Based on Dielectric-Metal Metasurface for Surface-Enhanced Infrared Sensing

2020 ◽  
Vol 10 (7) ◽  
pp. 2295 ◽  
Author(s):  
Guilian Lan ◽  
Zhongxie Jin ◽  
Jinpeng Nong ◽  
Peng Luo ◽  
Caicheng Guo ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Sensors ◽  
Incident Angle ◽  
Structural Parameters ◽  
Refractive Index Sensor ◽  
Perfect Absorber ◽  
Refractive Index Sensitivity ◽  
Infrared Sensing ◽  
Surface Enhanced ◽  
Infrared Frequencies

We proposed a narrowband perfect absorber that was based on dielectric-metal metasurface for wide-band surface-enhanced infrared sensing. It is found that the narrowband perfect absorber can generate the hybrid guided modes with high quality-factor at infrared frequencies, which make the absorber highly sensitive to the surrounded analyte. Moreover, tuning the incident angle can actively modulate the resonant wavelength of absorber. Such an absorber with excellent features is employed to realize both refractive index sensing and infrared vibrational fingerprint sensing on a single substrate. It is demonstrated that a refractive index sensitivity of 1800 nm/RIU and figure of merit of 62 RIU−1 can be obtained as the refractive index sensor. While, as a surface enhanced infrared absorption spectroscopy substrate, two closed vibrational modes of analyte with nanometer thick layers can be effectively identified and selectively detected with 50-folds enhancement by actively tuning the incident angle without any change in the structural parameters (periodicity, width, height, and refractive index of the grating) of the device after fabricating. Our study offers a promising approach for designing high-performance surface-enhanced infrared optical sensors in the infrared region.

Tuning the Fano resonances in a single defect nanocavity coupled with a plasmonic waveguide for sensing applications

2015 ◽  
Vol 29 (33) ◽  
pp. 1550218 ◽  
Author(s):  
Tiesheng Wu ◽  
Yumin Liu ◽  
Zhongyuan Yu ◽  
Han Ye ◽  
Changgan Shu ◽  
...  
Keyword(s):  
Refractive Index ◽  
Structural Parameters ◽  
Fdtd Method ◽  
Refractive Index Sensor ◽  
Fano Resonances ◽  
Refractive Index Sensitivity ◽  
Absorbing Boundary ◽  
Single Defect ◽  
Sensing Applications ◽  
Metal Insulator Metal

A novel surface plasmon polaritons (SPPs) refractive index sensor based on a single defect nanocavity coupled with a metal–insulator–metal (MIM) waveguide is proposed and numerically simulated by using the finite difference time domain (FDTD) method with perfectly matched layer absorbing boundary condition. It is found that the defect structure can realize two Fano resonances and these two Fano resonances originate from two different mechanisms. The results demonstrate the liner correlation between the resonance wavelengths of the device and the refractive index of the material under sensing. Through the optimization of structural parameters, we achieve a theoretical value of the refractive index sensitivity as high as 1800.4 nmRIU[Formula: see text]. It could be utilized to develop ultra-compact nanodevice for high-resolution biological sensing.

scholarly journals Enhanced Plasmonic Resonance Characteristics of AgNRs–Gold Film Hybrid System

2021 ◽  
Vol 8 ◽  
Author(s):  
Yanping Yin ◽  
Jin Zhu ◽  
Zaoji Wang ◽  
Guojun Ma ◽  
Huining Yuan ◽  
...  
Keyword(s):  
Refractive Index ◽  
Aspect Ratio ◽  
Gold Film ◽  
Spectral Response ◽  
Surrounding Medium ◽  
Resonance Wavelength ◽  
Spectral Shift ◽  
Refractive Index Sensor ◽  
Gap Size ◽  
Refractive Index Sensitivity

In recent years, the plasma gap resonance maintained by metal-film-coupled nanostructures has attracted extensive attention. This mainly originates from its flexible control of the spectral response and significantly enhanced field strength at the nanoparticle–film junction. In the present study, the tunability of local surface plasmon resonances (LSPRs) of nanorods coupled to a gold film is studied theoretically. To this end, the plasmonic resonances in the nanostructure of individual silver nanorod–gold film (AgNR-film) with different parameters are investigated. Obtained results show that the refractive index sensitivity (S) of nanostructures to the environment increases as the aspect ratio (Ar) of nanostructures increase. It is found that when the aspect ratio (Ar) is set to 3.5, the figure of merit (FOM) is the highest. Moreover, the variation in the gap distances of the nanorod monomer–gold film, electric field distribution of nanorods dimer, and the corresponding impact on the gold film are studied. It is concluded that the gap size of nanostructures has an exponential correlation with the resonance wavelength. Considering the remarkable influence of the gap size and the surrounding medium environment on the spectral shift of AgNR-film nanostructures, potential applications of the structure as a refractive index sensor and biomolecule measurement are proposed.

scholarly journals Sensitivity Enhancement of a Concave Shaped Optical Fiber Refractive Index Sensor Covered with Multiple Au Nanowires

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4210 ◽  
Author(s):  
Pathak ◽  
Rahman ◽  
Singh ◽  
Kumari
Keyword(s):  
Refractive Index ◽  
Structural Parameters ◽  
Localized Surface Plasmon ◽  
Refractive Index Sensor ◽  
Au Film ◽  
The Core ◽  
Enhanced Sensitivity ◽  
Guided Mode ◽  
Wide Range ◽  
Au Nanowires

In the present paper, a new kind of concave shaped refractive index sensor (CSRIS) exploiting localized surface plasmon resonance (LSPR) is proposed and numerically optimized. The LSPR effect between polaritons and the core guided mode of designed CSRIS is used to enhance the sensing performance. The sensor is characterized for two types of sensing structures coated with gold (Au) film and Au nanowires (AuNWs), respectively. The influence of structural parameters such as the distance (D) of the concave shaped channel (CSC) from the core, the diameter of the nanowire (dn) and the size (s) of the CSC are investigated here. In comparison to Au film, the AuNWs are shown to significantly enhance the sensitivity and the performance of the designed sensor. An enhanced sensitivity of 4471 nm/RIU (refractive index unit) is obtained with AuNWs, for a wide range of analytes refractive index (na) varying between 1.33 to 1.38. However, for conventional Au film; the sensitivity of 808.57 nm/RIU is obtained for the same range of analytes.

An Intensity Demodulated Refractive Index Sensor Based on A Hollow-Core Anti-Resonant Fiber

2022 ◽  
Author(s):  
Shidi Liu ◽  
Tianyu Yang ◽  
Liang Zhang ◽  
Ming Tian ◽  
Yuming Dong
Keyword(s):  
Refractive Index ◽  
Structural Parameters ◽  
High Sensitivity ◽  
Refractive Index Sensor ◽  
Hollow Core ◽  
Promising Candidate ◽  
Mid Infrared ◽  
Flow Through ◽  
Demodulation Method ◽  
High Absorption

Abstract A robust and simple mid-infrared hollow-core anti-resonant fiber (ARF) based refractive index (RI) sensor with an intensity demodulation method is presented and analyzed for monitoring liquid analytes. The ARF allows liquid analytes to flow through its hollow area for detection. To obtain ideal sensing performance, an epsilon negative (ENG) material is introduced into the selected anti-resonant tube. With the high absorption of the ENG material, only one fundamental mode is available for detection and is sensitive to the RI variation of analytes. Moreover, the effects of structural parameters on the sensing performances are discussed and analyzed to further understand the mechanism and optimization. The final result shows that the ARF sensor can exhibit a high sensitivity of -372.58 dB/RIU at a fixed wavelength within a broad RI range from 1.33 to 1.45, which covers most liquid analytes. It is a promising candidate for chemical and environmental analysis. Additionally, it has the potential for deep research to feed diverse applications.

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