Directionally controlled plasmon excitation in gold nanoparticles for near-field nanopatterning by femtosecond laser
Directionally controlled plasmon excitation in gold nanoparticles for near-field nanopatterning by femtosecond laser
复制标题
DOI：
10.1117/12.880738
复制
发表时间：
2010-09
期刊：
影响因子：
--
通讯作者：
T. Miyanishi;M. Terakawa;M. Obara;N. Nedyalkov;P. Atanasov
中科院分区：
文献类型：
--
作者：
T. Miyanishi;M. Terakawa;M. Obara;N. Nedyalkov;P. Atanasov
我们提出了理论和实验结果的纳米孔的制作在硅衬底上的多个金纳米粒子周围的等离子体激元近场的飞秒激光的斜入射激发。利用金纳米颗粒周围增强的近场，即使在近红外激光激发下，也可以在基底表面制造纳米孔。具有近红外入射波长的纳米孔的形成将为在空气中制造新的光学器件开辟智能应用。然而，金纳米粒子内部的等离子体受到邻近金粒子的等离子体的影响，导致近场分布的改变和等离子体共振波长的移动。这将导致纳米孔的形状不均匀，降低硅衬底上的近场强度。因此，控制等离子体激元的方向对于精确的纳米孔加工是非常必要的。我们提出了一种新的方法来减少粒子之间的等离子体激元相互作用，通过使用p偏振照射倾斜入射到衬底表面。实验和理论研究表明，当p偏振光束以最佳斜入射方式照射金纳米颗粒阵列时，可以通过抑制相邻等离子体激元的作用获得均匀的纳米孔。
We present theoretical and experimental results of nanohole fabrication on a silicon substrate by plasmonic near field around multiple gold nanoparticles excited by oblique incidence of femtosecond laser. Using the enhanced near field around a gold nanoparticle, nanohole can be fabricated on the substrate surface even at the near-infrared laser excitation. The formation of nanoholes with the near-infrared incident wavelength will open up smart applications for new optical device fabrication in air. However, the plasmons inside gold nanoparticles are affected by the plasmons of neighboring gold particles, resulting in an alteration of near-field distribution and the shift of resonant wavelength of plasmons inside the gold particles. These cause inhomogeneous shape of nanoholes and decrease the near-field intensity on silicon substrate. Therefore it is necessary to control the direction of plasmon for precise nanohole fabrication. We propose a new method to reduce plasmon interaction between particles by using p-polarized irradiation at oblique incidence to the substrate surface. Experimental and theoretical study demonstrated that uniformed nanoholes can be achieved by restraining effects from neighboring plasmon when p-polarized beam is irradiated to gold nanoparticle arrays with optimal oblique incidence.