Surface Plasmon Resonance
A semicontinuous gold layer on a template with a zig-zag structure has been demonstrated to be a highly sensitive substrate for surface-enhanced Raman scattering (SERS). Obliquely deposited gold layers on different templates yield different SERS strengths. In this work, a finite-difference time-domain method is utilized to analyze the electric field distribution within the gold layer when the film is illuminated by light. The random gold nanostructures are scanned and transformed into binary images to allow them to be simulated. The field intensities and SERS enhancement factors of different samples are calculated and compared. Our analysis results reveal the near-field characteristics of strong SERS and agree closely with experimental measurements.
Multilayered structures were designed on both sides of a thin silver film to let both transverse-magneticand
transverse-electric-polarized electromagnetic waves propagate along a thin metal film simultaneously
in the same configuration, as so-called long-range surface-plasmon-polariton (LRSPP) waves.
Based on the admittance analysis and design, the propagation length of an unpolarized LRSPP wave
can be extended by more than 1 order of magnitude compared with previous results.
A normalized admittance diagram assists in describing and designing multilayered structures to excite longrange surface-plasmon-polariton (LRSPP) waves of either the p- or the s-polarization state. These structures comprise symmetric periodic multilayers on one or both sides of a metal thin film in either the Kretschmann or the Sarid configuration. The normalized admittance diagram even assists in designing structures that can be used to excite LRSPP waves of both polarization states simultaneously.
