Naoki, Sheila, Camilla

To continue investigating alignment changes: 79105. More details in Sheila's 79127.

We put SRM back to before alignment shift, misaligned SRM2 and ITMs,  injected 1.28mW of SQZ SEED beam (as measured on SQZT7 OPO_IR_PD_DC_POWERMON). Followed as in 78115. Increased AS_AIR camera exposure form 10,000 to 100,000

Translated SQZ beam around last NLN spot, each direction the throughput was getting better but in both pitch directions we saturated ZM4 before moving far. Were able to get all expected 0.9mW throughput by moving ZM5 Pitch and yaw both positive.

• In starting alignment ASC-AS_C measured 0.1 to 0.2mW. Same after we centered beam on AS-C.  Time: 2024/07/15 17:52:14 UTC Plot. AS_AIR beam very bad.
• Moving ZM5 Positive YAW (recentering with ZM4 +Y), increased AS_C measured to 0.6mW before it started getting worse. Time: 2024/07/15 18:10:56 UTC Plot
• From this spot (ZM5 Positive YAW) we moved ZM5 Positive PITCH (recentering with ZM4 -P), increased AS_C measured to 0.9mW before it started getting worse Time: 2024/07/15 18:16:33 UTC Plot AS_AIR beam got better.
• We then went back to the original ZM4/5 alignment
• Moving ZM5 Negative YAW (recentering with ZM4 -Y) we were improving but saturating ZM4 before we could finish, AS_C measured to 0.44mW,  Time: 2024/07/15 18:55:00 UTC Plot
• Moving ZM5 Positive PITCH (recentering with ZM4 -P) we were improving but saturating ZM4 before we could finish, AS_C measured to 0.25mW,  Time: 2024/07/15 19:01:57 UTC Plot
• Moving ZM5 Negative PITCH (recentering with ZM4 +P) we were improving but saturating ZM4 before we could finish, AS_C measured to 0.22mW  Time 2024/07/15 19:12:57 UTC Plot
• Note the max we got when not aligned on AS_C was around 0.1mW, maybe caused by edge effects as expect 0.7% reflection off SRM HR surface = 0.7 x 1.28mW  = 0.896mW MAX.