[Daniel, Torrey]
We measured the actual beam going through the cavity with the beam profiller. The beam has a waist 13 cm after m2 and the 2 sigma waist diameter is 736 um. The intended beam has a waist at m3 and a diameter of 1210 um. The m2 to m3 distance is approximately 60 cm, so the waists are off by 47 cm. The cavity mismatch is 34% in this configuration according to finesse. To fix this with the current lenses, the last lens would need to go on top of a mirror. Thus, we are going to do a new mode matching solution tomorrow, hopefully one that is more robust to changes.
Attached is the first bowtie cavity in Finesse and my proposed mode matching solution. I am accounting for the curvature of the input mirror now. Also attached is the distances to noteable optics on this sled, for people's convenience. Note that we don't have the lenses for this mode matching solution. I have ordered some, as well as a surplus of weak, broadband 1064-1700nm coated lenses ranging from f=1m to f=2.5m. They should arrive monday or tuesday so we will try and finalize the cavity then.