• Chinese Journal of Lasers
  • Vol. 35, Issue s2, 215 (2008)
Wu Xuhua1、*, Chen Lei2, and Chang Jianhua1
Author Affiliations
  • 1[in Chinese]
  • 2[in Chinese]
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    Wu Xuhua, Chen Lei, Chang Jianhua. Calibration of the Frequency-response Function for Interferometer Based on Step-Phase Comparing Method[J]. Chinese Journal of Lasers, 2008, 35(s2): 215 Copy Citation Text show less

    Abstract

    When the phase wavefront is measured by a large aperture interferometer, there are anamorphic effects on the wavefront power spectral density (PSD) with high spatial frequency. So it’s necessary to calibrate the frequency-response function of the large aperture interferometer to guarantee the precision of the testing process. In this paper, the calibration principle of the frequency-response function is mainly discussed by adopting the wavefront PSD through the theoretical and experimental methods. After the calculation model of the frequency-response function is setup, the calibration methods such as sinusoidal phase grating method and step-phase comparing method are pointed out respectively. Depending on comparison between the advantages and disadvantages of these two methods, reasonable experiment method with a step is confirmed, which feasibility to calibrate an interferometer is also discussed thoroughly, and two necessary conditions for a step sample used to do calibration are given. Based on the principle of phase comparing, a standard phase object that contained a step phase is designed and fabricated. The frequency-response function is obtained by comparing the theoretical values and the measured value of the PSD. The experiment results and curves are also given in this paper. At last, the main error sources appeared in the testing process and their influences are systemically analyzed.
    Wu Xuhua, Chen Lei, Chang Jianhua. Calibration of the Frequency-response Function for Interferometer Based on Step-Phase Comparing Method[J]. Chinese Journal of Lasers, 2008, 35(s2): 215
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