| 摘要 |
PURPOSE:To obtain a two-dimensional interference pattern having a good contrast by permitting >=3 pieces of luminous flux, which are interferential with one another, and their propagation vectors to be contained in the plane of a prescribed circular cone or ellipsoidal cone and by overlapping them in the direction forming an angle mutually. CONSTITUTION:An interferometer is constituted so that the arrays of spot light source become vertexes of squares. In this interferometer, the intensity distribution of a two-dimensional interference pattern obtained in an area 24 where four pieces of parallel luminous flux overlap one another is represented in contour as shown in the figure. In this case, the center point encircled by four pieces of concentrical contour has intensity 1 and the intensity successively decreases to 0.9, 0.8- toward the outside, and the intensity on a section line forming each boundary becomes 0. In the intensity distribution when exposure is carried out twice through crossing unidimensional interference fringes, the two-dimensional intensity distribution having a clear contrast like this is not obtained. |
