Accuracy enhanced and synthetic wavelength adjustable optical metrology via spectrally resolved digital holography

作者:Claus D*; Pedrini G; Buchta D; Osten W
来源:Journal of the Optical Society of America A-Optics Image Science and Vision, 2018, 35(4): 546-552.
DOI:10.1364/JOSAA.35.000546

摘要

This paper demonstrates the usefulness of spectrally resolved digital holography for dual-wavelength optical metrology. Based on the large degree of phase information available, multiple de-correlated dual-wavelength phase maps can be generated, which, when averaged, result in a signal-to-noise-ratio improvement. Compared with single-wavelength averaging, no further post-processing of the reconstructed dual-wavelength phase map is required. Moreover, the constraint imposed on the wavelength stability, as experienced in the conventional dual-wavelength method, can be relaxed, and the corresponding synthetic wavelength is adapted to the object under investigation. In addition, the possibility of optical sectioning based on the narrow-width coherence envelope is also demonstrated in transmission mode.

  • 出版日期2018-4-1