Patent ID: 6741361
Filing Date: 2004-05-25
Classification: G01B

Abstract:
A multi-stage process for interpreting interferometric fluctuations of frequency-scanning interferometers comprising the steps of:producing a succession of N interference patterns between object and reference beams at N different beam frequencies within a range of beam frequencies; recording interferometric data for a corresponding area appearing in each of the N interference patterns, the interferometric data for the corresponding area cycling through conditions of constructive and destructive interference with variation in the beam frequencies; performing a first approximation of an interference frequency corresponding to a number of interference cycles the interferometric data for the corresponding area undergoes throughout the range of beam frequencies; determining bounds of the first approximation; performing a second approximation of the interference frequency within the bounds of the first approximation of the interference frequency; and converting the second or higher approximation of the interference frequency into a measure corresponding to a path length difference between portions of the object and reference beams that interfere within the corresponding area of the interference patterns.