[Ushiba, Komori, Fujimoto, Ono, Tamaki]

We aligned the beam on the REFL.

Mainly, we adjusted the angle of periscope and one PYD-20, or hight of HWP1 (blue circle in the Fig1), then checked beam pass was ok.

By adjusting the angle of circled PYD-20, the beam entered in CCD camera, but due to the influence of pink-circled one (what reflects IR beam to weaken power entering CCD), interferece fringes can be seen (Fig2).

Then we aligned the beam injected into RFPD and WFSQPD (orange circle).