Optimizing Nano-Optical Antenna for the Enhancement of Spontaneous Emission

Abstract

Abstract-We study the characteristics of nano-optical antenna made of two gold nano-particles by three dimensional numerical calculations in visible and near infrared bands. To carry the computational burden and guarantee the precision and speed of a three dimensional FDTD calculation, adaptive mesh refinement technology is used. In this paper, we first highlight the concrete way of controlling the emitter position and orientation to fulfill the requirements of larger spontaneous emission enhancement. Then, we analyze the far field distribution and find that the far field directivity is strongly influenced by surface plasmon polaritons (SPPs). Choosing the incident wavelength of 600 nm, we compute the decay rates and radiant efficiency as a function of antenna geometry limitations. Next, the particle aspect ratio is optimized, and we obtain that L/R = 4 is the best for our optical-antenna. Furthermore, we present a spectrum analysis. Around 5000 fold spontaneous emission enhancement is successfully achieved. Finally, we find a piecewise linearity relationship between the particle length and resonant wavelength.

Resonance Wavelength Dependence and Mode Formation in Gold Nanorod Optical Antennas With Finite Thickness

“…These nanoscaled metallic structures possess a wide variety of extraordinary optical properties which assume essential roles in applications such as efficient light localization [4,5], high resolution microscopy and spectroscopy [6][7][8], sensing [9,10], photodetection [11,12], light emission [13][14][15] and photovoltaics [16][17][18]. For many years technological difficulty in accessing nanoscale accuracy has strongly slowed down nanoantennas development, but in the last decade the impressive improvements in nanotechnology have removed this main limit and opened up the possibility to build antennas operating in the visible and infrared spectral ranges [19,20].…”

Finite-Boundary Bowtie Aperture Antenna for Trapping Nanoparticles

“…These trapping potentials have been normalized to the kinetic energy of the nanoparticles' Brownian motion in water at room temperature (with the trapping potential defined to be zero at some infinitely distant location). According to the work reported in [10,30], the assumption made about the injected power in the calculation is considered low, and safe to the nanoparticles. We infer from the simulation results presented in Figure 4(c) that gold nanoparticles with diameters as small as 12 nm can be stably trapped inside the gap region [29] (since the trapping potential is slightly higher than the kinetic energy of Brownian motion for d = 12 nm).…”

“…Optical antennas have been widely employed as nanosources for higher harmonic light [4,5], thermal emitters [6], plasmonic sensors [7,8], and in applications such as photodetection or spontaneous emission efficiency enhancement [9,10], optical trapping, stacking and sorting [11], and subwavelength field confinement [12].…”

Terahertz Plasmonic Cross Resonant Antenna

“…Of particular in this context are resonant optical antennas [7][8][9][10][11][12][13][14] which can efficiently convert optical radiation into localized and enhanced energy, and vice versa. Up to the present, several types of optical antennas have been proposed, such as dipole antenna [7,10,11], bow-tie antenna [9,15], and monopole antenna [16,17].…”