Optimizing bowtie structure parameters for specific incident light

• 来源期刊: 中国物理B（英文版）
• 关键词: bowtie aperture localized surface plasmons finite difference time domain method
• 年，卷（期）: 2010,（11）
• 页码范围: 588-592
• 页数: 5页
• 语种: 英文

摘要

We investigate optical properties of a bowtie-shaped aperture using the finite difference time domain method to optimize its geometric parameters for specific incident lights. The influence of the parameters on local field enhancement and resonant wavelength in the visible frequency range is numerically analysed. It is found that the major resonance of the spectrum is exponentially depended on the bowtie angle but independent of the whole aperture size. The simulation also demonstrates that increasing the aperture size raises the local field intensity on the exit plane due to an enlarged interaction area between the light and the metal medium. And the near-field spot size is closely related to the gap.Based on these results, the design rules of the bowtie structure can be optimized for specific wavelengths excited.