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Schematic representation of the interaction of (a) linearly polarized PW, (b) tightly focused linearly polarized beam, and (c) tightly focused radially polarized beam with a NP of radius ‘a’. Here, θ is the conic angle.
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Interactions of gold and silver spherical nanoparticles (NPs) of a wide range of radius size with tightly focused beams are investigated for a wide range of wavelengths. The scattering of tightly focused beams with a single NP of varying size is examined using a generalized Mie theory and average intensity enhancement in the near-field due to local...
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Context 1
... focusing of a radially polarized incident beam creates a much tighter focal spot [37]. We consider a tightly focused radially polarized beam as shown in figure 1 to examine its scattering from NP. Putting f = a cos and f = b sin in equation (11), the polarization distribution for a radially polarized incident beam at the exit pupil is expressed as [43] And the expansion coefficient A n is given as, ...Context 2
... order to further examine impact of exotic beam structures at the focal plane and consider its influence on the scattering from the NP, we considered scattering of a tightly focused radially polarized beam as shown in figure 1. Results of the average radial intensity enhancement for tightly focused radially polarized beam with Au-NP in air and glass are shown in figures 4(a) and (b). ...Similar publications
Laser-induced periodic surface structures (LIPSS) have gained significant attention due to their ability to modify the surface morphology of materials at the micro-nanoscale and show great promise for surface functionalization applications. In this study, we specifically investigate the formation of LIPSS in silicon substrates and explore their imp...
Citations
... While originally the phenomenon was observed and widely investigated using spherical gold nanoparticles (NPs), nowadays different sizes, shapes, and materials have attracted the interest of researchers [5][6][7][8][9][10][11][12][13]. For example, nanostars (NSs) and nanorods have different LSPR attenuation bands compared to spherical NPs due to variations in their shapes and structural properties, with the possibility of generating multiple resonances but mostly of tuning the resonance wavelength position and sensitivity [14][15][16]. ...
In this work, we present a detailed numerical and experimental investigation of highly sensitive optical fiber sensors based on localized surface plasmon resonance (LSPR). These sensors are enhanced by the deposition of nanoparticles (NPs) and nanostars (NSs) onto uncladded silica multi-mode optical fiber. The unique optical properties of NSs - featuring a 40 nm gold core surrounded by silver branches of variable size and shape - allows for precise tuning of the LSPR effect. For comparison, we also explored spherical gold NPs with a 40 nm diameter to assess performance differences. Our findings, both numerical and experimental, demonstrate that the LSPR wavelength and sensitivity to surrounding refractive index can be finely tuned by adjusting the morphology of the NS branches. This is achieved by varying the silver nitrate content during their synthesis. Using the Finite Element Method-based design tool we performed simplified study cases, that led to experimental sensitivity of approximately 560 nm/RIU for an LSPR wavelength near 810 nm. As a practical demonstration, the sensor was successfully employed to detect Thiram, a common agricultural pesticide, with a wide dynamic range from 10 pM to 100 µM and an impressive low limit of detection of 0.3 pM. Moreover, we investigated the sensor selectivity, stability and response to environmental temperature changes. This study emphasizes the simplicity, cost-effectiveness, and tunable performance of NS-based optical fiber sensors. By manipulating nanostructure morphology, we can significantly enhance sensor performance, positioning this technology as a highly promising solution for environmental monitoring, biomedical diagnostics, and chemical detection.
... CVBs, specifically radial and azimuthally polarized beams, exhibit symmetrical field distributions that enable novel interactions with plasmonic structures [10]. Radial polarization, where the electric field points outward from the beam's center, has been shown to improve coupling efficiency with surface plasmons [11,12]. Meanwhile, azimuthal polarization, characterized by electric fields circulating tangentially, presents different coupling dynamics, providing additional flexibility in plasmonic excitation [13]. ...
This study explores the effects of various polarization states on surface plasmon resonance (SPR) in circular gratings, emphasizing their potential in sensing technologies. We present a mathematical modeling framework alongside experimental investigations involving the fabrication and characterization of circular gratings using linearly polarized, radially polarized, and non-polarized light. Our findings demonstrate stable SPR responses across multiple polarization angles, with strong signals achievable even with non-polarized light, minimizing reliance on polarizers. Additionally, we analyze spatial intensity responses and the influence of polarization on excitation patterns, enhancing our understanding of plasmonic interactions. Through Surface Plasmon Resonance imaging (SPRi), we highlight the capability to capture topographical information, further contributing to advancements in plasmonics and the development of improved sensing devices.
The microscopic structure of living things in nature is the inspiration for many human science and technology, and the structural color of butterfly wings has been applied in many fields. In the field of solar cells, butterfly wings have been successfully replicated and applied to dye-sensitized solar cells (DSSC).However, the improvement of power conversion efficiency of DSSC with only one bionic structure is limited. So combining the local surface plasmon resonance (LSPR) effect with the nanostructure of bionic butterfly wings in DSSC is expected to achieve higher power conversion efficiency. In this paper, taking dye-sensitized solar cells as the research object, a novel composite structure has been developed and applied to the photoanode, and the power conversion efficiency of the device has been significantly improved. First of all, The LSPR effect of gold nanoparticles was verified by simulation analysis using FDTD Solutions. The gold colloid with the particle size of 30 nm was prepared by sodium citrate reduction method, and the gold colloid was introduced in the process of replicating the wings of Papilio bianor. The gold nanoparticle modified TiO2-BW (Au/TiO2-BW) was obtained and applied to the photoanode of DSSC. The results showed that compared with the DSSC prepared by ordinary P25 photoanode, the power conversion efficiency of DSSC prepared by Au/TiO2-BW photoanode increased by about 17%. Thanks to the synergistic effect of the microstructure of Papilio bianor wings and the LSPR effect, the light absorption capacity of the photoanode was enhanced, and the JSC was effectively improved. At the same time, the introduction of Au/TiO2-BW can effectively inhibit charge recombination and promote carrier transport.
Tropical diseases present significant challenges to global health, particularly in resource-limited regions. Early and accurate detection of these diseases is vital for effective management and control. In recent years, metallic-based LSPR sensors have emerged as promising diagnostic tools for sensitive and rapid detection of tropical diseases. This comprehensive review aims to provide an in-depth analysis of the current state of research on metallic-based LSPR sensors for the detection of various tropical diseases. In this study, we focused on the connection between neglected tropical diseases (NTDs) and its risk using metallic-based LSPR sensors to identify potential inflammatory biomarkers. We conducted a literature search using PubMed, Web of Science, and Google Scholar. Only published materials written in English were considered, resulting in the identification of ∼ 220 articles. After a comprehensive evaluation, we selected 35 relevant ones. Our analysis revealed 35 links to neglected tropical diseases, providing valuable insights into their relationship using metallic-based LSPR sensors. Moreover, we explore the potential of metallic-based LSPR sensors in point-of-care testing and their integration with emerging technologies such as microfluidics and smartphone-based diagnostics. This review underscores the need for continued research efforts to develop affordable, sensitive, and user-friendly metallic-based LSPR sensors for early detection and surveillance of tropical diseases.
