I'm meditating over the mode matching from the mode cleaner to the ITMs, and I had another thought:
Have we changed the pointing of the MC significantly enough that we are no longer on the center of the MMT mirrors? To be this significant, we would probably also have had to scoot the Faraday a bit too, since it's skinny like a straw. It looks like our measurements of the input beam have been the following:
MC waist, 21 May 2010
After MMT2, 18 June 2010 (a few days before this, we flipped the MMT2 mount to 'perfect' the mode matching up to 99.3%, so I don't think the MMT has moved since then.)
After MMT2, 26 March 2012
There's a big o' ~2 year gap between our measurements, and we've been in and out of the vacuum a few times since then. I'll flip through the elog, but does anyone have any memory of us moving the Faraday after June 2010? When was the last time we made sure that we were at least close to the center of the MMT mirrors?