表面等离激元光学力研究进展

Research progress in surface-plasmon-induced optical force

当一束光照射在物质上,光子与物质发生动量交换,部分动量转移到物质,等效于对物质产生作用力,称为光学力.这一作用力非常弱,一般在pN甚至更小的量级,但一定条件下,仍足以捕获和操纵纳米、微米尺度的物体.在金属纳米结构中,由于表面等离激元共振效应,诱导的局域电场可以产生增强的光学力,可以在亚波长尺度实现光操纵,并且由此衍生出一个极具吸引力的研究方向——表面等离激元光学力.本文介绍了利用金属纳米结构进行表面等离激元光学力操纵的最新研究进展.

When light shines on matter, part of the momentum of the incident photons is transferred to matter, resulting in a back-force acting on it, the so-called ＂optical force＂. This force is usually extremely weak of the order of pN or less. However, under certain circumstances, the optical force can be so strong that it is possible to optically trap and manipulate objects at the micro-/nano-scale. In metal nanostructures, the optical force can even be enhanced due to the excitation of surface plasmons, and the optical manipulation at the sub-wavelength scale becomes possible, leading to the derivation of an attractive research branch––surface-plasmon-induced optical forces. This paper will discuss the recent advances on the optical trapping and manipulation using surface-plasmon-induced optical forces.