带纳米金属棒PSTM孔径光纤探针成像的数值模拟

The simulation of photo scanning tunnel microscopy image with a metal nano-rod afflicted to an aperture fiber probe

用三维时域有限差分方法对带纳米金属棒孔径光纤探针成像进行了数值模拟。采用等高扫描从分辨率和灵敏度的角度分别讨论了纳米金属棒长度、扫描高度、孔径大小及镀膜厚度对成像的影响。数值模拟结果显示,带纳米金属棒镀膜孔径探针的性能主要受纳米棒的尺寸决定,较普通孔径探针在分辨率和灵敏度方面都有明显改进,并且稳定性更高。

The image of photo scanning tunnel microscope（PSTM）,using fiber probe coated by metal with a nano-rod at the edge of the aperture,is analyzed with 3-D finite difference time domain（FDTD）.The influences of the rod length,scanning height and different scale of apertures as well as different coating thickness on the resolution and sensitivity of PSTM are investigated with constant high scanning.The results show that the obtained images by the probe with a nano-rod,mainly determined by the parameters of the nano-rod,has higher resolution and sensitivity,while its stability is better.