Combining Cubic Spline Interpolation and Fast Fourier Transform to Extend Measuring Range of Reflectometry  

作　　者：Ju Cheng Jian Lu Hong-Chao Zhang Feng Lei Maryam Sardar Xin-Tian Bian Fen Zuo Zhong-Hua Shen Xiao-Wu Ni Jin Shi 程菊;陆建;张宏超;雷枫;Maryam Sardar;边心田;左芬;沈中华;倪晓武;施锦(School of Science, Nanjing University of Science and Technology;School of Physics and Electronic Electrical Engineering, Huaiyin Normal University)

机构地区：[1]School of Science,Nanjing University of Science and Technology,Nanjing 210094 [2]School of Physics and Electronic Electrical Engineering,Huaiyin Normal University,Huai＇an 223001

出　　处：《Chinese Physics Letters》2018年第5期20-24,共5页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant No 11604115;the Educational Commission of Jiangsu Province of China under Grant No 17KJA460004;the Huaian Science and Technology Funds under Grant No HAC201701

摘　　要：The reflectometry is a common method used to measure the thickness of thin films. Using a conventional method,its measurable range is limited due to the low resolution of the current spectrometer embedded in the reflectometer.We present a simple method, using cubic spline interpolation to resample the spectrum with a high resolution,to extend the measurable transparent film thickness. A large measuring range up to 385 m in optical thickness is achieved with the commonly used system. The numerical calculation and experimental results demonstrate that using the FFT method combined with cubic spline interpolation resampling in reflectrometry, a simple,easy-to-operate, economic measuring system can be achieved with high measuring accuracy and replicability.The reflectometry is a common method used to measure the thickness of thin films. Using a conventional method,its measurable range is limited due to the low resolution of the current spectrometer embedded in the reflectometer.We present a simple method, using cubic spline interpolation to resample the spectrum with a high resolution,to extend the measurable transparent film thickness. A large measuring range up to 385 m in optical thickness is achieved with the commonly used system. The numerical calculation and experimental results demonstrate that using the FFT method combined with cubic spline interpolation resampling in reflectrometry, a simple,easy-to-operate, economic measuring system can be achieved with high measuring accuracy and replicability.

关 键 词：FIGURE FFT Combining Cubic Spline Interpolation and Fast Fourier Transform to Extend Measuring Range of Reflectometry 

分 类 号：O484.5[理学—固体物理]