基于表面等离子体共振效应的椭圆柱银纳米线的光力研究

运用有限时域差分方法,研究了两椭圆柱银纳米线之间的光力及其物理机制,并且分析了椭圆柱银纳米线的尺寸以及相对位置对光力的影响.结果表明:椭圆柱银纳米线的尺寸以及相对位置等结构参量的变化导致两椭圆柱银纳米线之间光力的明显变化.由于局域耦合共振,Ag纳米颗粒间的内壁上存在电子的振荡行为,将微腔中光子的能量转化成电子集体振荡的动能,这使得微腔中的电磁场能量减小到负能态,从而产生收缩的负光力.因此,Ag纳米颗粒间相互吸引.

Plasma Resonance and Optical Forces Between Two Ellipsoidal Silver Nanowires

Based on the finite-difference time-domain method, the optical forces between two ellipsoidal silver nanowires and the physical mechanism were investigated. The effect of the relative position and the dimention of two ellipsoidal silver nanowires on the optical forces were analyzed. A slight change of them would result in an obvious change of the optical force. The silver internal electrons were oscillated due to local coupling resonance. The plasma resonance would convert the photon energy in cavity into the kinetic energy of electronic collective oscillation. The electromagnetic field energy was reduced to negative state, which caused the contractive and negative optical force. Therefore, ellipsoidal silver nanowires attracted each other.