title: A separation of the refractive index and topography in photon-scanning tunneling microscopy: simulations and experiments.
abstract: 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.
authors.affiliation: Department of Physics, Dalian University of Technology, Dalian 116024, China. wangxqdl@sina.com
authors.forename: Xiaoqiu
authors.initials: X
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Yinli
authors.initials: Y
authors.lastname: Li
authors.forename: Guoshu
authors.initials: G
authors.lastname: Jian
authors.forename: Wei
authors.initials: W
authors.lastname: Suen
authors.forename: Shi
authors.initials: S
authors.lastname: Pan
authors.forename: Shifs
authors.initials: S
authors.lastname: Wu