Validation of electromagnetic field enhancement in near-infrared through Sierpinski fractal nanoantennas.

We introduced fractal geometry to the conventional bowtie antennas. We experimentally and numerically showed that the resonance of the bowtie antennas goes to longer wavelengths, after each fractalization step, which is considered a tool to miniaturize the main bowtie structure. We also showed that the fractal geometry provides multiple hot spots on the surface, and it can be used as an efficient SERS substrate.

LSPR enhanced MSM UV photodetectors.

We fabricated localized surface plasmon resonance enhanced UV photodetectors on MOCVD grown semi-insulating GaN. Plasmonic resonance in the UV region was attained using 36 nm diameter Al nanoparticles. Extinction spectra of the nanoparticles were measured through spectral transmission measurements.

'Fairy Chimney'-shaped tandem metamaterials as double resonance SERS substrates.

A highly tunable design for obtaining double resonance substrates to be used in surface-enhanced Raman spectroscopy is proposed. Tandem truncated nanocones composed of Au-SiO(2)-Au layers are designed, simulated and fabricated to obtain resonances at laser excitation and Stokes frequencies. Surface-enhanced Raman scattering experiments are conducted to compare the enhancements obtained from double resonance substrates to those obtained from single resonance gold truncated nanocones.

Nanoantenna coupled UV subwavelength photodetectors based on GaN.

The integration of nano structures with opto-electronic devices has many potential applications. It allows the coupling of more light into or out of the device while decreasing the size of the device itself. Such devices are reported in the VIS and NIR regions.

Electron beam lithography designed silver nano-disks used as label free nano-biosensors based on localized surface plasmon resonance.

We present a label-free, optical nano-biosensor based on the Localized Surface Plasmon Resonance (LSPR) that is observed at the metal-dielectric interface of silver nano-disk arrays located periodically on a sapphire substrate by Electron-Beam Lithography (EBL). The nano-disk array was designed by finite-difference and time-domain (FDTD) algorithm-based simulations. Refractive index sensitivity was calculated experimentally as 221-354 nm/RIU for different sized arrays.