| 摘要 |
An alignment device is provided for aligning a primary mirror with a secondary mirror in an optical system having the primary mirror and the secondary mirror arranged so as to face each other along the optical axis. The alignment device has a dichroic film formed on a surface on the front side of the secondary mirror and configured to reflect light used in the optical system and to transmit alignment light, a back reflecting surface formed on the back side of the secondary mirror and configured to reflect the alignment light, and a detection system which detects a positional deviation between the primary mirror and the secondary mirror, based on the alignment light having traveled via the dichroic film, the back reflecting surface, and a reflecting surface of the primary mirror. |
