title: Wavenumber scanning-based Fourier transform white-light interferometry.
abstract: Fourier transform white-light interferometry recovers the optical path difference of an interferometer by measuring the phase change caused by scanning wavelength. However, the optical spectrum, obtained by wavelength scanning method (λ-method), contains a chirp in period. The chirp would induce deviation and decrease the measurement accuracy. An improved method, the wavenumber scanning method (k-method), is proposed and experimentally demonstrated, in which there is no chirp in the optical spectrum. The measurement results using the k-method and the λ-method are compared experimentally. The experimental results show that the standard deviation of the measurement results decreases from 0.015 to 0.004 μm, when an extrinsic Fabry-Perot interferometer with a cavity length of 387 μm is interrogated.
authors.affiliation: School of Opto-Electronics, Beijing Institute of Technology, No. 5 Zhongguancun South Street, Haidian District, Beijing 100081, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: Jiang