Our lens positions for mode matching into the PMC seem to be based ON LIES. I cannot locate my old data on the first PSL scans and fitting. I have now learned a very important lesson in imitating Aidan.

Since my old "measurement" (quoted number) seems to disagree with what I have found by roughly a sign, I am operating under the assumption that I was simply wrong in the linked entry.

I have plotted our old mode matching solution with the new beam parameters.

I have also found 2 mode matching solutions for the "average" mode coming out of the PSL, one with two 500mm lenses, and an alternative in case we don't have them around.

If these do not suffice for our locking needs, we will need to deal with the ellipticity of the beam. I think it will be fine for now based on this.

I have included plots of the two offered mode matching solutions, as well as the picture of what we were using for coupling into the cavity.