Vicky, Naoki, Sheila

Summary: We tried to improve squeezing by walking alignments, this wasn't sucsesful.  We did see that we were able to increase the ADF IQ SUM while decreasing sqz, which we didn't understand.

Since we saw a small improvement in sqz on the homodyne yesterday after moving ZM3, today we tried to move the filter cavity axis to see if we could reduce clipping while injecting sqz into the IFO.  We injected the ADF and set offsets on the FC green trans green QPD A, and watched for higher ADF.  The QPD offset didn't have much of an effect itself, we did however see a 10% increase in the ADF IQSUM channel while the AS42 loops had a large transient because of our QPD step.  

We were able to recreate the higher ADF IQ SUM by setting an offset of -0.3 in AS_A_RF42_YAW, but this didn't visibily improve the squeezing or range (we tried switching the offset back and forth several times, the initial improvement wasn't reproduced). 

We did some further steps, and saw that we could increase the ADF IQ SUM even further, but that the squeezing level was reduced with the higher ADF.  We wondered if we were being confused by a change in the squeezing angle.  We checked the sqz angle with and without the yaw offset engaged, rotating the sqz angle didn't explain the difference we saw with the alignment offset.