Miniature optical sensors that specifically identify low concentrations of environmental and biological substances are in high demand. Currently, there is no optical sensor that provides identification of the aforementioned species without amplification techniques at naturally occurring concentrations. Recently, it has been demonstrated that triangular silver nanoparticles have remarkable optic...

In this paper, a fast and sensitive localized surface plasmon resonance (LSPR) based biosensor was developed and the optimization of gold – antibody conjugates through investigation of different parameters were performed. Gold nanoparticles (AuNPs) with a size of ~20 nm were synthesized via chemical reduction of HAuCl4 with trisodium citrate as reducing and stabilizing agent. The impacts of pH ...

Intrinsic coherent anti-Stokes emission is observed in lithographically patterned gold nanowires. Polarization dependent measurements reveal that the nanostructure's anti-Stokes response is polarized in the direction of the transverse surface plasmon resonance of the wire. We have used specially fabricated gold nanozigzag wires that are modulated in height between 20 and 80 nm to demonstrate tu...

For a fiber optical surface plasmon resonance (SPR) sensor a short part of its cladding should be removed to coat a thin layer of a metal. Usually this is problematic when an optical fiber with small core diameter is used. In this paper, a new method using µliter droplet of the HF acid for short fiber optical taper fabrication is reported. Using this method in a multi-mode optical fiber w...

The Green’s-theorem integral equation formulation is employed to study numerically the coupling into surface plasmon polaritons by illuminating a finite metal grating with a Gaussian beam from the vacuum half-space above the metal surface. A flat surface impedance boundary condition is used to simplify the scattering integral equations. The grating coupler period is chosen so that the first dif...

Thin Film Physics Division, Department of Physics, Chemistry and Biology, Linköping University, 581 83 Linköping, Sweden Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology (INT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany Joint Research Laboratory Nanomaterials (KIT and TUD) at Technische Universität Darmstadt (TUD), Jovanka-Bontschits-Str. 2, 64287...

We have developed a self consistent technique to predict the behavior of plasmon resonances in multi-component systems as a function of wavelength. This approach, based on the tight lower bounds of the Bergman-Milton formulation, is able to predict experimental optical data, including the positions, shifts and shapes of plasmonic peaks in ternary nanocomposites without using any fitting paramet...

Controlling plasmon-exciton coupling through band gap engineering of plasmonic crystals is demonstrated in the Kretschmann configuration. When the flat metal surface is textured with a sinusoidal grating only in one direction, using laser interference lithography, it exhibits a plasmonic band gap because of the Bragg scattering of surface plasmon polaritons on the plasmonic crystals. The contra...

In this manuscript pairs of flexibly linked silver nanoparticles, so called silver plasmon rulers, are synthesized using a rational DNA programmed self-assembly procedure. The plasmon resonance energy (E(res)) versus distance relationship is calibrated for dimers comprising sphere-like silver nanoparticles with diameters of 41.0 ± 4.6 nm and surface-to-surface separations between 1-25 nm. Singl...

Dual-mode surface-plasmon resonance (SPR) sensors use both long- and short- range surface plasmon waves to differentiate surface binding interactions from interfering bulk effects. We have optimized the design of these sensors for minimum surface limit of detection (LOD) using a Cramer-Rao lower bound for spectral shift estimation. Despite trade-offs between resonance width, minimum reflectivit...