Metallic Plasmonic Array Structures: Principles, Fabrications, Properties, and Applications

Abstract

can efficiently couple light into nanostructures and confine light below diffraction limit. [8,9] With these properties, plasmonics have found important applications in various fields such as plasmonic sensing, [10][11][12][13] plasmon-enhanced spectroscopies, [14][15][16] plasmonic nanolasing, [17][18][19] and perfect light absorption. [20,21] The optical performances of plasmonic nanostructures are highly dependent on the resonance modes that they support. Generally, there are two fundamental surface plasmonic modes: localized surface plasmon resonance (LSPR) and propagating surface plasmon polaritons (SPP). [22,23] LSPR can be observed on metal nanoparticles. [22,24,25] However, the strong radiative damping of metal nanoparticles results in broad resonant spectra, severely limiting the applications of metal nanoparticles in fields such as plasmonic sensing and nanolasing. [26,27] SPP is usually generated at the interface between metal and dielectric with the assistance of a high refractive index prism or by constructing a grating structure. [23,28,29] The near-field decay length of SPP mode is 40-50 times larger than that of LSPR mode. [23] Therefore, SPP structures usually provide higher bulk sensitivity when used for plasmonic sensing. [23] However, it is difficult to achieve a flexible tuning of SPP mode only by above configurations. In addition, single resonance mode also greatly limits the applications of the devices.According to the plasmon hybridization theory, coupling of different resonance modes can endow plasmonic nanostructures with richer optical properties and thereby improve their performance and broaden their application fields. [30][31][32] Metallic plasmonic arrays have been demonstrated to be a powerful platform for the simultaneous excitation of the above two basic types of plasmonic modes. [33,34] In addition, they can also support many other types of resonance modes such as Fabry-Pérot (F-P) cavity mode, surface lattice resonance (SLR), and plasmonic Fano resonance due to the flexibility in structure design. [32,[35][36][37][38] These modes together give the nanostructured plasmonic arrays with attractive performance unattainable by using individual LSPR or SPP mode. Benefited from the abundant optical properties, nanostructured metallic plasmonic arrays can be utilized in a fashion of "device-by-design." For example, for plasmonic sensing, a plasmonic array with a narrow spectrum can be fabricated for an excellent sensing performance; [23,26] while for surface-enhanced Raman spectroscopy (SERS) detection, a plasmonic array with a relatively broad spectrum is needed to achieve local field enhancement and radiative enhancement simultaneously. [39,40] Therefore, the investigation The vast development of nanofabrication has spurred recent progress for the manipulation of light down to a region much smaller than the wavelength. Metallic plasmonic array structures are demonstrated to be the most powerful platform to realize controllable light-matter interactions and have found wide application...

Engineering Efficient Self-Assembled Plasmonic Nanostructures by Configuring Metallic Nanoparticle’s Morphology

“…The local field or near-field enhancement opens up an attractive optical property strongly relying upon the optical resonance of metallic nanostructures. These significantly enhance the electromagnetic field, mainly due to surface plasmon resonance (SPR) [13][14][15][16][17]. The electromagnetic field or near-field enhancement in plasmonic materials has generated significant interest in understanding various plasmonic modes [18][19][20][21].…”

“…Factors such as geometrical shape, size, material choice, doping, and surroundings (ex., such as a coated surface layer with different refractive index material) play a vital role in manipulating plasmonic properties in self-assembled nanostructures based upon application requirements [1,[4][5][6][7]13,[16][17][18][19][20]. It is essential to consider that this generated near-field is not uniformly distributed all over nanostructures but relatively highly localized in spatially narrow regions such as interparticle nanogaps, nanotips, or NP-spacer nanogaps, which were called hot-spots [1,[5][6][7][16][17][18][19][20]31,32]. One of the critical properties in effectively optimizing the hot-spot region will be the NP shape or surface morphology.…”

“…One of the critical properties in effectively optimizing the hot-spot region will be the NP shape or surface morphology. In optimizing hot-spot, NP shapes such as sphere, disk, and cube play an essential role, as reported in the vast literature [5,6,[13][14][15][16][17][18][25][26][27][28][33][34][35][36][37]. In particular, NP shapes such as spheres and cubes can help to fabricate self-assembled plasmonic nanostructures, owing to their commercial availability.…”

Numerical Investigation of Multifunctional Plasmonic Micro-Fiber Based on Fano Resonances and LSPR Excited via Cylindrical Vector Beam

“…often has high sensitivity to surrounding environment [25][26][27]. LSPR brought by different metal nanostructures i.e., nanoparticles [28], nanorods [29], nanostars [30] is also utilized in optical sensing for its ability of wavelength shift with the change of the surrounding [31] and enhancing scattering [32]. LSPR is significantly polarization-dependent [33][34][35], making it possible to improve the sensing performance through changing the illumination methods.…”

Designing an Efficient Self-Assembled Plasmonic Nanostructures from Spherical Shaped Nanoparticles

“…Factors like geometrical shape, size, material choice, doping, and surroundings (ex., like a coated surface layer with different refractive index material) play a vital role in the manipulation of plasmonic properties in self-assembled nanostructures based upon application requirements [1,[4][5][6][7]13,[16][17][18][19][20]. It is essential to consider that this generated near field is not uniformly distributed all over nanostructures but relatively highly localized in spatially narrow regions like interparticle nanogaps, nanotips, or NP-spacer nanogaps, which were called hot-spots [1,[5][6][7][16][17][18][19][20]31,32]. One of the critical properties in effectively optimizing the hot-spot region will be the NP shape or surface morphology.…”