mesoSPIM_excitation_path_L4_alignment
As noted above, the distance between L4 and M6 (the galvo) needs to be the focal length of a L4. This allows the L3-L4 relay to reimage the focusing action of the tunable lens into the back focal plane of the scan lens. For this, an alignment collimator is placed on the raised FLS-40 rail and used at full beam size. By directing the beam via M4 to L4 and onto M6, the spot size on M6 can be used to set this distance.
Direction matters:
Move L4 in the cube back and forth till the spot on the scanner (M6) is minimal in size.
L4 insertion
L4 to M6 adjustment
