I spent some time tonight trying to revive DRMI locking, with the arms held off on ALS. Not much news, I haven't been able to get more than a few short spurts of resonance, using 1F signals.

I did use SRY to measure the BS->SRCL coupling by exciting each mirror and looking at their relative coupling to AS55Q. I found that we should use a value of +0.28 +-0.01 in the MICH->SRM element.