Refractive index sensing characteristics of dual resonances in rectangular fractal nano-apertures

Recent advances in the metamaterial and metasurface-based biosensor in the gigahertz, terahertz, and optical frequency domains

“…Sensing platforms based on the aperture configuration can be used for the biosensing applications [ 171 ]. A dual-resonant nano-antenna array based on the aperture configuration of complex rectangular fractal was introduced by Aslan et al for ultra-sensitive biosensing and chemical applications [ 172 ]. Another example includes the works of Cetin et.…”

Shaping the Plasmonic Response: Hollow Gold Elliptical Nanotubes

“…[ 13 ] Multiple resonances are key to nonlinear harmonic generation [ 14–16 ] and improving the figure of merit of multichannel refractive index sensing. [ 17–19 ]…”

“…[13] Multiple resonances are key to nonlinear harmonic generation [14][15][16] and improving the figure of merit of multichannel refractive index sensing. [17][18][19] Considerable efforts have been devoted to engineer the spectral and spatial plasmonic properties beyond conventional dipolar responses of basic geometries such as nanospheres, nanotubes, and nanowires. The most common mechanism to achieve required LSP resonances is assembling several basic nanoparticles together where the near-field coupling results in hybridized or emerging plasmonic modes together with dramatic light confinement.…”

Fractal Shaped Periodic Metal Nanostructures Atop Dielectric-Metal Substrates for SERS Applications

“…29,230 Generally, these resonances are associated with the formation of subwavelength-localized areas with strong FEs, so-called hot spots, in the regions of constructive interference of corresponding (localized and/or propagating SP) modes. 29 Fractal structures featuring various FE effects have found diverse applications, 30 ranging from subwavelength imaging, 31 broadband absorbers, 32 sensors, 33 to graphene photodetectors. 34 We have previously explored light scattering by fractal shaped periodic arrays of gold nanoparticles fabricated on thick gold films, and associated generation of localized FEs.…”

“…Considering approaches to cover large substrate areas with nanostructures, the usage of fractal patterns in the geometry of plasmonic nanostructures is appealing because these structures are known to support multiple tunable resonances over broad spectral domains. Generally, these resonances are associated with the formation of subwavelength-localized areas with strong FEs, so-called hot spots, in the regions of constructive interference of corresponding (localized and/or propagating SP) modes . Fractal structures featuring various FE effects have found diverse applications, ranging from subwavelength imaging, broadband absorbers, and sensors to graphene photodetectors . We have previously explored light scattering by fractal-shaped periodic arrays of gold nanoparticles fabricated on thick gold films and associated generation of localized FEs. , The boundary of such a structure is defined by the shape of the Mandelbrot fractal, and hot spots are produced inside the structure due to the interference of (excited by scattering of incident radiation) SPP waves that are reflected and diffracted at the boundaries. , The underlying physical mechanism of hot spot generation is therefore similar to the mode formation in acoustic fractal drums .…”