On Friday I reattached the omega-straps to the FI. The operation went very smoothly, and the magnet securely rests on all points of contact (see photos).

After that Mike and I have moved the granite block under the FI to allow beamscans to be made on the edge of the optical table. We did it by first moving the periscope to a clean cart, leaving 3 alignment posts to determine the position of the FI. We then moved the granite block, and finally reinstalling the FI the to positioning posts.

I have setup an output periscope by stealing the bottom ALS periscope mirror. The final setup is shown in the attached .png file. The list of moved mirrors in the current setup:

OSA and OSA mount are moved out of the beam path

IO_AB_L4 is moved out of the beam path

IO_AB_M12  moved to position (170;3) to serve as 1st turning mirror in FI testing path

IO_AB_M8 moved to (170;31) as the 2nd turning mirror

A HWP obtained from Rick is in (180;31)

IO_AB_M10 moved to (186;31)

2" mirror from eLIGO HAM7  at (186;45)

2" mirrors from eLIGO comprize pol-preserving periscope (182;45)

The beam passes through the FI (locked at an angle), and is eventually dumped on a water-cooled 300 W power meter at (132; 148)

The output periscope presently does not contain a TOP mirror. This will need to alternate between a 180 deg reflector for alignment, and a ~1% beamsplitter for thermal measurements.

ALS_M4 mirror was moved to (146;48) to act as the bottom periscope mirror.

IO_AB_M13 moved to (146; 53) as the beam camera mirror.

I have partially assembled the FI HWP rotator assembly, including the 16 roll-bearings and springs. However the springs are attached only on the top, and the motor itself is not in place.

I have also placed a temporary 1" siskiu mount on a set of clean washers for the alignment of DKDP. DKDP itself is not yet installed.

The optical alignment itself is in the same state as on Thursday, with both s- and p-pol beams leaving the FI.