| 摘要 |
PURPOSE:To obtain an interdigital type pattern by using the interference fringes of two sets of coherent light and executing one simple mask displacement between them. CONSTITUTION:A light sensitive material 4 is exposed to the interference fringes of coherent lights 1 and 2 through the opebing of a mask 3. Next, coherent lights 1' and 2' are projected to the light sensitive material 4 through the opening of a mask 3'. The interference fringes at this time are positioned in the intervals between the adjacent interference fringes of the previous step. To do so, the mask 3' must be moved parallel to the interference fringes of the previous step by a distance DELTA. Carry out the second exposure in this state. The interference fringe patterns P1 and P2 thus obtained by the first and the second exposures become the interdigital type patterns of a constant pattern interval l respectively when the coherent lights are all plane waves, and the adjacent intervals of the interdigital type pattern vary as l1<l2<l3 when the coherent light 1 or 1' is a plane wave one and the 2 or 2' is a cylindrical surface wave one. |
