先后在脉冲平面波和环形高数值孔径聚焦倏逝场两种不同的入射场条件下，使用时域有限差分(FDTD)方法对金属平行纳米棒结构和U型纳米结构的表面等离子体(SPs)激发特性进行了仿真研究。在脉冲平面波入射条件下，发现两种纳米结构在可见光波段具有相同的表面等离子体共振(SPR)激发波长。在此波长的线偏振光环形聚焦倏逝场中对这两纳米结构激发SPs的特性进行了仿真。结果表明，U型纳米结构具有最佳的局域场增强和远场传导能力，可构成等离子体光镊用以捕获纳米粒子。

The excitation properties of the surface plasmons (SPs) excited by the metallic parallel-nanorod and U-shaped nanostructures are simulated under the illumination field conditions of pulse plane wave and circular high numerical aperture focal evanescent field using the finite difference time domain (FDTD) method. Under the illumination of pulse plane wave, the two nanostructures present the same surface plasmon resonance (SPR) wavelength in the visible range. After that, we simulate the excitation properties of SPs excited by the two nanostructures in the fields of the circular high numerical aperture focal evanescent beam with the same SPR wavelength. The simulation results indicate that the U-shaped nanostructure performs the best local field enhancement and far field transmission ability, which can be used to construct a plasmonic tweezer for trapping nano-particles.