Transition of surface-plasmon resonance from out-of-plane photonic crystal effect is observed in a semiconductor array of subwavelength holes by optical pump-terahertz probe measurements. The dielectric properties of the photoexcited array are essentially altered by the intense optical excitation due to photogenerated free carriers. As a result, the array becomes metallic and favors the couplin...

We show high resolution measurements of a surface plasmon resonance (SPR) sensor based on a rectangular nanohole array in a metal film. This SPR setup uses balanced intensity detection between two orthogonal polarizations of a He-Ne laser beam, which allows for sensitivity improvement, noise reduction and rejection of any uncorrelated variation in the intensity signal. A bulk sensitivity resolu...

We investigated grating-coupled transmission-type surface plasmon resonance (SPR) for sensing applications. In the transmission-type SPR structure, propagating surface plasmons are outcoupled to radiation modes by dielectric and metallic gratings on a metal film. The results calculated in air and water suggest that the proposed structures present extremely linear sensing characteristics. In ter...

Optical chiral metamaterials have recently attracted considerable attention because they offer new and exciting opportunities for fundamental research and practical applications. Through pragmatic designs, the chiroptical response of chiral metamaterials can be several orders of magnitude higher than that of natural chiral materials. Meanwhile, the local chiral fields can be enhanced by plasmon...

In this work, a novel photoelectrochemical biosensing strategy was designed for cell assay under 630 nm (red light) excitation. WS2/Au NP nanocomposites were prepared as a photoelectrochemical biosensing substrate. The localized surface plasmon resonance effect of Au NPs tremendously improved the photoelectric conversion efficiency and enhanced the detection sensitivity.

Localized surface plasmon resonance (SPR) biosensors with metallic nanowires regularly patterned on a gold film are considered for sensitivity nhancement. The theoretical investigation was conducted using rigorous coupled wave analysis in terms of various design metrics, such as the esonance angle shift, the SPR curve angular width, and the minimum reflectance at resonance. The results show tha...

An in-hole nanohole surface plasmon resonance sensing scheme is demonstrated. Arrays of periodic nanoholes milled through thin layers of SiO(x) and gold were used to detect the binding of organic and biological molecules inside the nanoholes, while blocking the gold surfaces outside the holes. This new approach is more efficient than the previous nanohole array method, where the response was re...

We report on the observation of Feshbach resonances in an ultracold mixture of two fermionic species, (6)Li and (40)K. The experimental data are interpreted using a simple asymptotic bound state model and full coupled channels calculations. This unambiguously assigns the observed resonances in terms of various s- and p-wave molecular states and fully characterizes the ground-state scattering pr...

We demonstrate the use of tilted fiber gratings to assist the generation of localized infrared surface plasmons with short propagation lengths and a sensitivity of dlambda/dn = 3,365 nm in the aqueous index regime. It was also found that the resonances could be spectrally tuned over 1,000 nm at the same spatial region with high coupling efficiency (in excess of 25 dB) by altering the polarizati...