Plasmonic Nanostructures for Optically Induced Movement

Abstract

Optical forces generated at the nanoscale using electric field gradients have proven to be a powerful tool for trapping and moving nano-objects in a variety of application fields ranging from aerospace engineering to biology and medicine. Typically, to achieve this optical effect plasmonic resonant cavities that combine localized surface plasmon resonances and propagative surface plasmon polaritons are used. Indeed, these structures allow to engineer the distribution of the excited field hotspots, so inducing a precise movement of the nanoparticles interacting with the plasmonic field. In this paper, starting from the theoretical analysis of the surface plasmons, the potentialities of plasmonic nanostructures are reviewed, analysing the geometric conformation designed according to the application. The configurations with the most interesting performance, among those mentioned in the literature, are described in detail, examining their main characteristics and limitations. Finally, the future development and prospects of these plasmonic nanostructures are discussed.

Polarization-Addressable Optical Movement of Plasmonic Nanoparticles and Hotspot Spin Vortices

“…However, in this paper, the system generates an evanescent wave, and, through the formation of spin momentum, it follows trajectories reliant on the polarization of the incident beam, owing to the induced plasmonic field. The ability to manipulate the position of a resonant system using a simple plane wave offers intriguing advantages, particularly in the plasmonic propulsion for the nanoparticle exit angle control [31][32][33]. In addition, functionalizing the plasmonic system holds promise in biosensing, drug delivery, and cancer therapy applications [25,26].…”

“…We show that the trajectory of a gold monomer can be addressed by the polarization of the incident beam. This polarization-dependent variation involves many applications regarding the control of plasmonic particles, such as in optical tweezers and metasurfaces [29,30], and also in the plasmonic propulsion of nanoparticles [31][32][33]. Secondly, we study the behavior of the spin angular momentum in the case of a gold dimer.…”

2D MXenes as a Promising Candidate for Surface Enhanced Raman Spectroscopy: State of the Art, Recent Trends, and Future Prospects

“…Therefore, the plasmonic metal nanostructures’ amplification of E in the nano‐evanescent field is essential for the EM effect. [ 49 ] In addition, the CT reaction between materials and molecules becomes straightforward when intermediate energy states are formed along with the formation of chemical bonds, thus producing a clear Raman amplification effect. However, the CM enhancement effect is 10 0 –10 2 times smaller than the EM enhancement in terms of amplitude.…”

Orthogonal mode couplers for plasmonic chip based on metal–insulator–metal waveguide for temperature sensing application

“…This domain delves into the interactions between electromagnetic (EM) waves and unbound electrons within tiny metallic structures, leading to the creation of surface plasmons (SPs) that can confine and control light at the nanoscale. The impact of plasmonics extends widely, with practical applications in diverse fields like optics 2 , sensing 3 , 4 , and information technology 5 . Plasmonic structures can be designed to amplify the sensitivity and precision of sensors, enabling the detection of exceedingly small quantities of molecules or nanoparticles 6 , 7 .…”