Here are the CCD movies at TMSX when ITMX was shaken at 0.1 Hz. The first movie was taken just after the second lens (RLNS2). The second movie is around the X axis's waist (z~1000, with z=0 at RLNS2). The last movie is at around z=1500. At the far field (z=1500). It shows pitch-and-yaw coupled motion. We'll check if this PY coupling is seen by the QPD at a far field or not. If not, we'll leave the beam as is and install the two QPDs with 90 deg Gouy phase separated, or if two QPD positions with 90 deg Gouy phase separated without PY coupling. We'll investigate the beam more if not.

[Hirose, Kokeyama, Remote Ushiba]