Plasmonic array nanoantennas on layered substrates: modeling and radiation characteristics

Abstract

In this paper, we theoretically characterize the performance of array of plasmonic core-shell nano-radiators located over layered substrates. Engineered substrates are investigated to manipulate the radiation performance of nanoantennas. A rigorous analytical approach for the problem in hand is developed by applying Green's function analysis of dipoles located above layered materials. It is illustrated that around the electric scattering resonances of the subwavelength spherical particles, each particle can be viewed as an induced electric dipole which is related to the total electric field upon that particle by a polarizability factor. Utilizing this, we can effectively study the physical performance of such structures. The accuracy of our theoretical model is validated through using a full-wave finite difference time domain (FDTD) numerical technique. It is established that by novel arraying of nano-particl and tailoring their multilayer substrates, one can successfully engineer the radiation patterns and beam angles. Several optical nanoantennas designed on layered substrates are explored. Using the FDTD the effect of finite size substrate is also explored.

Experimental demonstration of reflectarray antennas at terahertz frequencies

“…Beyond the millimeter wave range, the concept of reflectarrays have been extended to the infrared band, where a binary phase reflectarray has been realized using subwavelength metallic patches on a dielectric substrate to act as a reflective Fresnel zone plate [7]. In addition, nano-sized spherical particles with a core-shell structure have been investigated as concept for an optical reflectarray [16,17]. By independently configuring the material properties or radii of the core and shell structures, the reflected phase change can be controlled.…”

Faced folded rods as nano-antenna for optical devices

“…Besides, the electric field near metal surface is abruptly enhanced by a surface charge oscillation, also called local plasmon. The electric field enhancement when the metal edges build a gap has been demonstrated in a bow-tie antenna, coupled metallic rods and nano-particle array 12,13,14 .On resonance, strong field enhancement in the nano antenna gap is observed. In this paper, in order to construct more hot spots, two single folded rods are faced each other.…”

Numerically Efficient Analysis of Array of Plasmonic Nanorods Illuminated by an Obliquely Incident Plane Wave Using the Characteristic Basis Function Method

“…In our numerical results, we assume x = 150 nm and y = 250 nm satisfy this criterion. By replacing the closed form for Int k r in (37) into the spectral representation of the mn-element of the CBF impedance matrix in (35) and by noting that there is only one visible Floquet mode, we obtain the following where N T is the truncation number for the infinite series embedded in the spectral representation of z CBF G mn as follows…”