We tried to redo the mode matching to RCAV by adjusting the lense position using translational stages. However the result does not improve that much. The visibility is still roughly the same at 96.5%.
We will do the mode match for ACAV. Right now the visibility for ACAV is ~90%.
We also monitored the beam reflected from ACAV. TEM02 shows up (see below figure), but we could not get rid of it by beam alignment. It is probably the distortion from the AOM.