摘要 |
A frequency-shifting interferometer gathers intensity data from a set of interference patterns produced at different measuring beam frequencies. A periodic function is matched to the intensity data gathered from the set of interference patterns over a corresponding range of measuring beam frequencies. Localized correlations involving phase offsets between the interfering portions of the measuring beam are used to inform a determination of a rate of phase change with measuring beam frequency corresponding to the optical path length difference between the interfering beam portions. |