| 摘要 |
PROBLEM TO BE SOLVED: To provide an algorithm which is hardly affected by light of 0th order in a phase distribution measuring method using the grating shearing interferometer. SOLUTION: This method, using a grating shearing interferometer which has two equally formed phase type diffraction gratings 1 and 2 arranged in parallel to each other while having their pitches in the same direction, the phase type diffraction grating 2 which can shift in the pitch direction is used to measure the phase distribution of light E which is made incident on this interferometer. The method has a process for measuring the intensity distribution of 2N+1 interference fringes by shifting the phase type diffraction grating 2 by p/2N.j (j=0, 1, 2..., 2N), where (p) is the pitch of the gratings and N is a natural number of 3 or more, and a process for finding the phase distribution of the light E based on the N intensity distributions obtained by averaging the intensity distributions of (k)th (k=0, 1, 2... N) interference fringes and intensity distributions of (k+N)th interference fringes.
|
