jenne.driggers@LIGO.ORG - posted 18:07, Tuesday 04 October 2022 - last comment - 19:53, Tuesday 04 October 2022(65220)
Touched up EOM in FSS optical path, no strong effect on 2.5 MHz peak
[RyanS, Louis, Jenne]
We went in to the PSL enclosure today to see if adjusting the EOM in the FSS optical path would have an effect on the 2.5 MHz peak. Mostly, it didn't, unless we changed its alignment enough that we were clipping (and therefore lowering the optical gain in the FSS system). However, after we came out Daniel pointed out that the more useful EOM to try adjusting is the phase correcting EOM that is just after the NPRO, since that's the one that is an actuator for the FSS loop. We'll go in and try that later this week.
alog 17885 describes that there is a notch in the EOM path at ~1.8MHz. Plot goes to 2.5MHz and there maybe something visible just below.