[Kambara, Furuhata, Akutsu]

The BS oplev is on the way to the installation. This is the fisrt vertical optical lever. The difficulty is that Akutsu missed that the ~ 22.5 deg mirror will be required for the beam having the angle-of-incident of 45 deg to bent to horizontal toward QPD. Anyway, the light beam from a light source from the lower side (BS-F9) is hitting the BS, and exitting from the upper side (BS-F10). By the way, the reflection from the rear side is also strong...