Abstract：Fourier transform spectrometer is an important instrument in the remote sensing applications. There are phase error problems in the Fourier transform spectrometer signal processing procedure. In the present paper, the cause of phase error of Fourier transform spectrometers is shown firstly. It is mainly because of inaccuracy of sampling. Then the nonlinearity of phase error is analyzed. It is suggested that it is because that the interferogram is of finite length and the interferogram is discrete that this nonlinearity exists. The authors studied this problem with a new method. The nonlinearity is shown by rigorous derivation and the authors draw the conclusion by reasoning. Then through the nonlinearity of phase error, the authors have a discussion on the possible error in the Mertz phase correcting method. The possible error lies in the phase interpolation procedure, a part of Mertz method. A method consisting of zero adding and transforming is given to reduce this error. The methods are compared and illustrated by an experiment which uses simulated interferogram from standard spectrum library. The experiment demonstrates that the method of zero adding and transforming can reduce the phase error of phase interpolation and improve the problem of rapid phase change under some circumstances, which can help get better spectrum.
[1] Mertz L. Transformations in Optics. New York: Wiley, 1965. [2] Mertz L. Infrared Phys., 1967，7: 17. [3] Sanderson R B, Bell E E. Applied Optics, 1973, 12(2): 266. [4] Forman M L, Steel W H, Vanasse G A. J. Opt. Soc. Am., 1966, 56: 59. [5] Sakai H, Vanasse G A, Forman M L. J. Opt. Soc. Am., 1968, 58: 84. [6] Bell R J. Introductory Fourier Transform Spectroscopy. New York: Academic Press, 1972. [7] WENG Shi-fu(翁诗甫). Fourier Transform Infrared Spectrometer(傅里叶变换红外光谱仪). Beijing: Chemical Industry Press(北京：化学工业出版社), 2005. [8] WU Hang-xing, HUA Jian-wen, WANG Pei-gang, et al(吴航行，华建文，王培纲，等). Infrared Technology(红外技术)，2004，26(4)：25. [9] Revercomb Henry E, Buijs H. Applied Optics, 1988, 27(15): 3210. [10] ZHANG Tian-shu, LIU Wen-qing, GAO Min-guang, et al(张天舒，刘文清，高闽光，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析)，2006，26(3)：430. [11] Chase D B. Applied Spectroscopy, 1982, 36: 240. [12] Griffiths Peter R, de Haseth James A. Fourier Transform Infrared Spectrometry. New York: John Wiley & Sons, 1986. [13] LI Zhi-gang, WANG Shu-rong, LI Fu-tian(李志刚，王淑荣，李福田). Spectroscopy and Spectral Analysis(光谱学与光谱分析)，2000, 20(2): 203. [14] FAN Shi-fu, LI Yan-ning, ZHAO Yu-chun, et al(范世福，李艳宁，赵玉春，等). Analytical Instrumentation(分析仪器)，1995，(2)：51. [15] Leamer Richard C M, Thorne Anne P, Wynne-Jones Jan. J. Opt. Soc. Am. A, 1995, 12(10): 2165.
