INFLUENCE OF ACTIVE NANO PARTICLE SIZE AND MATERIAL COMPOSITION ON MULTIPLE QUANTUM EMITTER ENHANCEMENTS: THEIR ENHANCEMENT AND JAMMING EFFECTS (Invited Paper)

Abstract

Abstract-In the 150 years that scientists and engineers have used Maxwell's equations to describe electromagnetic phenomena, canonical scattering and radiating problems have played a very important role, providing explanations of and insights into their underlying physics. With the same intent, a variety of active coated nano-particles are examined here theoretically with regard to their ability to effectively enhance or jam the responses of quantum emitters, e.g., fluorescing molecules, and nanoantennas to an observer located in their far-field regions. The investigated spherical particles consist of a gain-impregnated silica nano-core covered with a nano-shell of a specific plasmonic material. Attention is devoted to the influence of the over-all size of these particles and their material composition on the obtained levels of active enhancement or jamming. Silver, gold and copper are employed as their nanoshells. The over-all diameters of the investigated coated nano-particles are taken to be 20 nm, 40 nm, and 60 nm, while maintaining the same ratio of the core radius and shell thickness. It is shown that the jamming levels, particularly when several emitters are present, are significantly larger for particles of larger sizes. These configurations are also shown to lead to the largest enhancement levels of the surrounding quantum emitters. Furthermore, for a fixed particle size and for a gain constant that produces the largest enhancement peak at optical wavelengths, it is demonstrated that these larger levels are most notable when the nano-shell is gold.

Cylindrical and Spherical Active Coated Nanoparticles as Nanoantennas: Active Nanoparticles as Nanoantennas

“…Both the near and far field behaviours of a variety of passive and active CNPs shown in Figure 1 have been studied in our previous works [3,Ch. 4], [37,42,77,78,81,82,84]. The results for the passive cases indicate where the geometry resonances occur, which can be tuned by the geometry shape/size and the material parameters.…”

“…The NRR behaviours reported below and the near-field characteristics of the S-CNPs excited with a single or with multiple EHDs were reported in [3,Ch. 4], [42,77,78]. Their directivity behaviours were studied thoroughly in [84].…”

“…As reported in [3,Ch. 3], [42,77,78], both enhanced and reduced radiation/scattering effects can be achieved in various CNP configurations. In particular, specific spherical CNPs, denoted here as S-CNPs, can be designed to be resonant and wellmatched to the radiating EHD, which leads to large enhancements in the total radiated power.…”

“…On the other hand, other nano-antenna designs can significantly reduce emissions. It has been shown that CNP designs can effectively jam the fields radiated from a single or from multiple emitters [42,77,78]. Non-radiating or dark states associated with the passive configurations were recognized in [79].…”

Passive and active metamaterial-inspired nano-scale antennas

“…Electrically small antenna designs have been realized with a single metamaterial unit cell and small sets of them; they have been shown to have many potential applications. The metamaterial-inspired, near field resonant parasitic (NFRP) paradigm also has been extended to visible wavelengths, leading to active ENZ optical metamaterials [3], as well as passive and active nano-antennas [4]- [8]; nanolasers [9], [10]; highly directive nano-antennas [10]- [12]; nano-amplifiers [13], [14]; and quantum jammers [13]- [15].…”