采用‘分割光束’的方法模拟计算了光子扫描隧道显微镜样品表面近场光强。用平面波对一维结构光盘进行的初步计算结果表明其表面近场光强分布相当复杂,一般情况下近场光强分布并不能真实地描述表面结构,近场光强受到表面结构很强的调制。当针尖与样品间距增大时,光强分布上会迭加上一些微小的波动。光强分布和样品表面结构之间会产生位移,这可能影响利用扫描近场光学显微镜进行纳米加工和定位。将数值计算结果与他人的实验结果进行了比较。

A numerieal sim ulation is used to cakulate the near—field intensity by “split light beam ”. The preliminary resuRs of the calculation on one dimension compact disk sample using plane wave are demonstrated. It shows that the near—field intensity profiles have rather complicated structures. In many cases the near—field intensity does not represent the actual surface profile. The near—field intensity is strongly modulated by the surface structure. When the distance between the sample and the proble becomes larger, some subtle oerturhation is added to the intensity profile. and a shift be tween the surface profile and the intensity distribution be came more remarkable. The shift may cause some problems when we use the optical probe as a multi—function probe to do some lithograph work or to position. A comparsion be tween the calculation and other experimental results is also made.