采用时域有限差分方法计算全内反射和光子扫描隧道显微镜系统。光子扫描隧道显微镜的基本工作原理是隐失波的产生和探测,当入射光在两种介质的分界面上发生全内反射,并在界面处产生非辐射的电磁波――隐失波时,采取对两界面入射光进行分别设置的方法即“三波法”设置入射激励元。分别计算一个球和两个球形样品的近场分布,并计算散射小球为探针,一个球为样品的扫描图像。结果表明:采用二维时域有限差分方法计算能较直观地显示样品表面的近场分布。表明时域有限差分方法在光子扫描隧道显微镜理论研究中具有很大潜力。

The total internal reflection and the system of photon scanning tunneling microscope(PSTM) are simulated using finite difference time domain(FDTD) method. The basic principle of photon scanning tunneling microscope is that the surface evanescent wave generated under total internal reflection condition and the surface evanescent wave is explored. The incident wave is set throughout the problem space in photon scanning tunneling microscope into three-wave included the incident wave, reflective wave and transmitted evanescent wave. The intensity distribution of near field of sphere samples is calculated. And the scanning images can be obtained when the probe of sphere scans along a line above the sphere samples. The results show that the finite difference time domain method is an efficient tool for photon scanning tunneling microscope.