This is a quick update on 57906, the last part of which has information about mode matching for the F path.

I moved the optics in the F path (CLF to OPO matching), the attached photo shows this path as it is now, no longer interfering with the transmitted beam from SFI1.  The +150mm ROC lens F:L1 is placed 40mm from the front of the collimator adapter ring, (the collimator lens itself is a couple of mm behind the front of the ring). The distance from the front of the collimator ring to the steering mirror F:M1 is 205mm, and there is about 102 mm from F:M1 to the OPO mirror M2.  With this set up the 2nd order mode has about 10% as much power as the 00 mode.