偏心纳米管结构的光学吸收和散射特性分析

Absorption and scattering properties of gold nanotubes with an offset core

摘要:

利用时域有限差分法，理论研究了内核偏移量、内核材料和外界环境以及入射光入射方向对偏心金纳米管的吸收和散射强度的影响。结果表明，随着内核偏移量的增大，吸收和散射光谱均发生红移，且吸收和散射强度的比值随着内核偏移量的增大而增大，并且，当内核材料介电常数增大或外界环境介电常数减小时，该比值增大。而入射光入射方向对该强度比值影响则较复杂。利用等离激元杂化理论对该现象进行了解释。

Abstract:

The effects of core offset, dielectric constants of core and embedding medium as well as incident light direction on the absorption and scattering properties of gold nanotubes with a nonconcentric core are theoretically studied by the finite difference time domain method. The numerical results show that the absorption and scattering spetra red shift and the absorption-scattering ratio increases with increasing core offset distant of the inner core from the nanotube centre. Moreover, the absorption-scattering ratio also increases with the increased core dielectric constant or the decreased dielectric constant of embedding medium. When the incident light direction is parallel to core offset direction, the greater absorption-scattering ratio appears as the position of the core is close to the incident light, but the ratio is smaller than that one when the incident light direction is perpendicular to offset direction as the core offest is given.