title: Resonance modes, cavity field enhancements, and long-range collective photonic effects in periodic bowtie nanostructures.
abstract: The discovery of single-molecule sensitivity via surface-enhanced Raman scattering on resonantly excited noble metal nanoparticles has brought an increasing interest in its applications to the molecule detection and identification. Periodic gold bowtie nanostructures have recently been shown to give a large enhancement factor sufficient for single molecule detection. In this work, we simulate the plasmon resonance for periodic gold bowtie nanostructures. The difference between the dipole and the quadrupole resonances is described by examining the magnitude and phase of electric field, the bound surface charge, and the polarization. The gap size dependence of the field enhancement can be interpreted by considering cavity field enhancement. Also, additional enhancement is obtained through the long-range collective photonic effect when the bowtie array periodicity matches the resonance wavelength.
authors: Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan. hsuehc@ntu.edu.tw
authors: Chun-Hway
authors: CH
authors: Hsueh
authors: Chih-Hong
authors: CH
authors: Lin
authors: Jia-Han
authors: JH
authors: Li
authors: Nahla A
authors: NA
authors: Hatab
authors: Baohua
authors: B
authors: Gu
mesh_terms: D053768:Metal Nanoparticles / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D017785:Photons; D012542:Scattering, Radiation; D013059:Spectrum Analysis, Raman / Q000379:methods*; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D008670:Metals