Coupling-induced excitation of a forbidden surface plasmon mode of a gold nanorod

• 来源期刊: 中国科学G辑（英文版）
• 年，卷（期）: 2009,（8）
• 页码范围: 1129-1138
• 页数: 10页
• 语种: 英文
• DOI: 10.1007/s11433-009-0171-5

摘要

Using the finite-difference time-domain (FDTD) method, we simulate the coupling between a gold nanorod and gold nanoparticles with different plasmonic resonant frequencies/volumes as well as that between the nanorod and a dielectric nanosphere. The influences of coupling with different nanoparti-cles on the excitation of a forbidden longitudinal surface plasmon mode of the nanorod under normal incidence are investigated. It is found that the cause of this excitation is the broken symmetry of the local electric field experienced by the nanorod resulting from the charge pileup on the other nanopar-ticle. This result is valuable for understanding the near-field optical characterization of plasmonic metal nanoparticles.