DETERMINATION OF OPTICAL PATH DIFFERENCE BY MEASURING COLOR VARIATION OF WHITE INTERFERENCE FRINGE

摘要

PROBLEM TO BE SOLVED: To quantitatively and readily estimate an optical path difference from interference color by a method wherein a scale curve is formed on a phase space in a predetermined number of dimensions on the basis of the relationship between a spectrum distribution obtained from interference color based on the interference of two kinds of white lights and the optical path difference between the two kinds of the white lights and the optical path difference of the two kinds of lights is obtained from a spectrum distribution created by a light of which optical path difference is unknown on the basis of the scale curve. ;SOLUTION: A characteristic value of a correlation matrix is calculated on the basis of a thirty one-dimensional data vector that is obtained such that 201 pieces of interference colors are made from optical path difference 0nm to optical path difference 1000nm in every 5nm and sampled in very 10nm, thereby obtaining seven base vectors. Since a visually representative space is a three-dimensional one, the above data is indicated on a figure where it is developed on the three-dimensional space designated by the first, second and fourth base vectors. The optical path difference is obtained from the spectrum distribution corresponding to the interference color based on the scale curve formed in accordance with the above method.;COPYRIGHT: (C)1997,JPO