It is found that the best resolution still exists in the near-field optical microscope for these dielectric particles and happens at the position where the far field counteracts the near field.

• 利用麦克斯韦电磁场理论和偶极近似方法,导出了光场与介质球的相互作用常数,证明了近场光学显微镜对介质仍然存在最佳分辨,最佳分辨效果出现在近场与远场相消的位置。