I have measured the beam profile coming out of the 775nm collimator for the first filter cavity and calculated a mode matching solution. The mode matching solution can be found at "\Nextcloud\GQuEST\B102\Output Filter Cavity\775_OFC_MM.jam". Note the the implementation varies by +/- 1 inch for each lens. 775nmprofile.png is a measurement after putting the lenses in. I can then use my finesse code to predict the mismatch in the cavity. This calculation yields up to 1% mismatch.

Note that per a previous log post, the newport 1550 HR mirrors do not reflect enough light at low AOI and 775nm. We will need to replace all the mirrors in the cavity. When this happens we will move the curved optic to the M3 position. This calculation takes that into consideration. This will then require a new mode matching solution for the 1550nm light. For now though, we are ready to inject 775nm light into the cavity.