mesoSPIM_excitation_path_M1_M2_alignment
M1 and M2 can then be added to the bottom cage rods suspended below both CPVM plates. Their height above the optical table does not matter. Adjust the position and rotation of M1 so that the laser beam footprint is centered on M2, then align the beam through the ETL so that it propagates along the axis of the raised FLS-40 rail. An iris with a SM1 cageplate on a FLS40 carrier might help with that.
Centering the beam on M2
Prepare the cage rods and cage plate to insert M3. You can use an additional
FLS-40 carrier to mark the position.