| 摘要 |
PURPOSE:To generate an optional optical path difference by eliminating the parallel movement of an emitted light to keep one parallel plane mirror away from the other to the position as far as mechanical conditions permit. CONSTITUTION:The rotation angle of a rotary plane mirror 13 is changed synchronously with the movement of a moving mirror 11 out of a pair of parallel plane mirrors 11 and 12, which generate a change of optical path length, to make a light incident to the center of a rotary plane mirror 14. If the light is reflected three times by the mirror 11, the distance between a virtual image 24 of the mirror 14 generated by mirrors 11 and 12 and the mirror 14 is six times as long as a length l between mirrors 11 and 12. When the mirror 13 is so rotated that the reflected light of the mirror 13 is made incident to a center 32 of the image 24, the reflected light is made incident to a center 31 of the mirror 14. The position of the displaced mirror 11 is indicated by broken line 11', and the distance between a virtual image 25 of the mirror 14 in the position of the mirror 13 and the mirror 14 is six times as long as a length l' between mirrors 11' and 12. In this case, the light is made incident to the center 31 of the mirror 14 also. When the quantity of displacement of the mirror 11 and the rotation angle of the mirror 13 are determined in this manner, the light is made incident to positions 26-30 similarly. |
