| 摘要 |
PURPOSE:To accurately monitor the movement of a moving mirror through a simple construction, by installing an auxiliary semi-transmission mirror consisting of two prisms between a main fixed mirror and the moving mirror. CONSTITUTION:The semi-transmission mirror 13 consisting of the rectangular prisms 11, 12 is installed between the main fixed mirror 3 and the moving mirror 4 so that the semi-transmission mirror 13 extends almost parallel with a main semi- transmission mirror 5. Monochromatic light emitted from a light source 8 is introduced into a face (a) of the semi-transmission mirror 13 so that the light is divided into two portions. These portions are totally reflected by the faces of the prisms and conducted to the moving mirror 4 and an auxiliary fixed mirror 6. The portions of the light are then reflected by the mirrors 4, 6, returned through the same optical paths and synthesized with each other by the auxiliary semi-transmission mirror 13. As a result, interference takes place. A detector 9 supplies a pulse signal with the movement of the moving mirror 4. |
