Yesterday the cavity has been aligned and locked with the CW Koheras laser.

the FSR has been measured by modulation technique at 133.344MHz at 1mbar pressure in the cavity.

the polarization has to be optimized for the Finesse measurement otherwise, some "shoulders" appear beside the Airy peak and reduce Finesse fit.

once it is done, 3 consecutive measurements give an average Finesse of 20800.