A separation of the refractive index and topography in photon-scanning tunneling microscopy: simulations and experiments.
In order to separate the purely optical and topographic information from images in constant-gap mode simultaneously, we proposed the atomic force/photon-scanning tunneling microscopy (AF/PSTM). In this paper, we focus on the principle of separation of the refractive index image from the images of photon-scanning tunneling microscopy. We prove the formula of refractive index imaging by using a three-dimensional finite-difference time-domain method. The formula indicates that the refractive index of a sample is approximately proportional to photon tunneling information (DeltaI/I )2. From the viewpoint of practical use, we simulated the refractive index images for the realistic experiments. We present line scans along two orthogonal directions and the transmitted intensity as a function of the tip position under the constant-gap mode. The experimental results are presented and are in good agreement with the numerical results.
Wang
Xiaoqiu
X
Department of Physics, Dalian University of Technology, Dalian 116024, China. wangxqdl@sina.com
Zhang
Jian
J
Li
Yinli
Y
Jian
Guoshu
G
Suen
Wei
W
Pan
Shi
S
Wu
Shifs
S