This morning I went to the bifurcated laser hazard and adjusted alignment of the ALS SHG path on ISCT1, picking up where Jenne left off yesterday.  Drawing here

The IR beam was reasonably centered on the bottom periscope mirror and the 1" steering mirror right after it, it was clipping on the 1" BS used for the monitor PD.  I yawed the 1" mirror right after the periscope to reduce the clipping, seen on a card right after the BS.  Then I continued to yaw that first steering mirror to get a beam transmitted through the SHG, as you translate the beam you can see lots of glints transmitted which aren't the actual beam.  As soon as there was full beam going through the SHG, the green beam was alinged onto the COMM A broadband PD, so I didn't move any steering optics other than the first one.  

The monitor diodes do not agree with the power levels that they showed before the table move.  The IR one shows 6 times more power than before the table move, which makes me think the diode may not have been well aligned at the end of O4.  The beam in reflection off that first beamsplitter has two lobes visible on a card, possibly the front and back surfaces of the BS.  The beam was clearly missing the green power monitor PD, (before photo), I moved the diode to center, but the beam is still too low.  Nearly a year ago TJ and I wrote that this diode wasn't working, 84558, it does but seems to have been working since June 9th 2025, a day when the table was realigned as described in 84900. Since this alignment puts the beam onto the COMM diode, which is quite far from the SHG, I think it must be similar to previous alignments, and we probably need to adjust the height of this diode.

The power on the COMM A PD is about 300 counts, similar to what it was in O4.  So, this is probably a good enough alignment for us to proceed with locking with.