Optimized Sensitivity and Electric Field Enhancement by Controlling Localized Surface Plasmon Resonances for Bowtie Nanoring Nanoantenna Arrays

Abstract

The surface plasmon resonances of gold bowtie nanoring antenna arrays were simulated using the finitedifference time-domain method in the present study. Both the local field and transmission spectra of bowtie nanoring antennas with various nanohole sizes were examined to find the optimum conditions to induce the greatest local electromagnetic field enhancement and sensitivity compared to the solid bowtie antenna. With the optimized nanohole size of bowtie nanoring, the local electromagnetic field enhancement, the decay length of the electric field, and the bulk sensitivity were increased as high as about 73, 349, and 63 %, respectively, compared to the solid bowtie antenna. The electric field enhancement profile and the charge distribution of the bowtie nanoring antennas were studied to characterize the coupled plasmon configurations, and it was used to explore the mechanism of enhanced sensitivity and resonance-wavelength shift of bowtie nanoring array with different surrounding dielectric media. This highly localized electromagnetic field enhancement and sensitive bowtie nanoring array system can be applied in the field of surface-enhanced Raman scattering and bio-sensing.

Integration of bow-tie plasmonic nano-antennas on tapered fibers

“…Besides that, it would be possible to measure sensitivities experimentally on the magnitude order predicted by Calderón and colleagues [31] and our device is more compact compared to long periodic gratings based sensitivity devices [32]. Moreover, it would also be possible to improve the sensitivity figure by placing a circular hole within the bowtie nano-antenna triangular element as demonstrated by Nien et al [33].…”

Ultra High Figure-of-Merit Mushroom Nanoantenna Array for Refractive Index Sensing

“…Bowtie and bowtie nanoring nantenna arrays' performance are studied in [9]. The sensor consists of gold bowtie with 200 nm side length, bowtie gap width of 40 nm and the hole size inside the bowtie varied from 20 nm to 50 nm.…”

Free-standing gold elliptical nanoantenna with tunable wavelength in near-infrared region for enhanced Raman spectroscopy

“…Localized surface plasmon has been widely used on surface-enhanced Raman spectroscopy (SERS) [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Coupling between two metal surfaces separated by few nanometers brings localized surface plasmon to resonate at the gap and induces large electromagnetic field enhancement.…”

“…The resonance wavelength is strongly dependent on the geometry of the antenna, and the enhancement factor can be manipulated by the gap distance [1] or the corner radius [17]. Recently, the enhancement factor has shown the dependence on the column and row distances of the periodic nanostructure due to the long-range resonance between each individual bowtie antenna [2][3][4][5]. The maximum enhancement can be achieved as the periodic distance in the polarization direction matches the incident wavelength for the bowtie structure [6].…”