Vicky, Camilla
Took ZM4,5,6, SRM alignment and PSAMs back to their values on 2024/07/17 20:18 to 20:23 UTC as in 79193. Plot here. We hope this will allow the SQZ beam through the OFI. SDFs for ZMs attached but not saved (incase we want to revert them if SQZ beam not seen), SRM optical align alignments were 2240, -3436 before as not svn monitored. SRM WD was tripped, Tony reset this.
SQZ OPO is seed dither locked but I can't see the most of the beam power on the SQZT7 diode. Vicky pointed out I should use the RLF QPDs to check for FC1, ZM1,2,3 pointing, they looked bad but there was some light on the QPDs, moved alignment sliders to get the FC1, ZM1,2,3 osems to be the same as 2024/07/17 20:18 to 20:23 UTC. This made the beam completely off the QPDs so I reverted, plot and sdf attached. We started walking the beam with FC1 and ZM3 as in 75509. Then Daniel asked if we had the TECs on...d'oh. after the TECs were turned on we had the QPDs saturating and I reverted all ZM1,2,3 and FC1 changes.
After lunch: Can reduce SEED power and check centering on QPDs. Can open SQZT7 and check the beam is going though the irises.
Jennie, Camilla, Naoki, TJ
Put SEED back to 75mW, IR PD still had 0.79mW (expect (1.3mW), we tried reverting ZM4,5 to the values this morning, before I corrected for the vent, this dropped the power further.
Only 0.7mW was making it to SQZT7. We dropped SEED power for 75mW to 5mW, started well centered on QPDA but -0.7 off QPDB_PIT, plot. We moved ZM3/FC1 to improve this to 0.88mW . We are normally +0.3 off in PIT, see attached. Later, once we were on SQZT7, Naoki noticed that this alignment wasn't good enough as SK beams were not co-aligned. Photo attached.
On SQZT7 we used ZM4 to align to first iris and ZM5 to align to second iris, now H1:SQZ-OPO_IR_PD_DC_POWERMON increased to 0.96mW, still now 1.3mW we're expecting. Opened Beam divertor, TJ then checked that the SQZ beam was making it to SRM and back through the OFI! We can even see SQZ light on AS_C, plot attached. Not easy to take a photo of the beam on the KTP yet.
The SQZ alignment we liked is attached, sdf'ed and was what we had at 2024/07/19 23:00UTC.
Next week, we can decide to keep this alignment or improve the SK co- alignment and realign ZM4,5 path. We should then take our set of power measurements through the OFI/SRM.
