Yesterday, we tried to better adapt positions of the telescope lenses, dynamically, during the lock, to improve the matching between input beam and cavity mode.
it is a difficult task because it is quite sensitive to the alignment. we need to realign very often... and it is a long process.
at the end, we concluded that we need to move to much the lenses to be feasible, then we stopped.

then we tried also to change the cavity mode by moving the spherical mirrors inside the cavity but again, the telescope is too far from its expected parameters.
we need to make a cavity mode smaller at high power and we need to move too far the spherical mirrors, then we stopped also this trial.

the conclusion is we need to better measure the cavity mode and make a telescope better adapted to the "hot" cavity.
it is still strange to measure a tranmsission signal AND a coupling signal with a "thermal" decay at the beginning of the lock for both and we expect that they complementary and should vary in contrary direction.
very strange as we use very large PhD which should net be sensitive to misalignments.