Measurments of Finesse with the 2 polarization states, let's call them H (higher) and L (lower): 24500 for the H and 23500 for the L.
We checked the polarization states in transmission of the FP cavity after a PBS. The H was stronger in PBS trans and the L stronger in PBS ref.
We measured the power in reflection of the PBS and added a half WP that we aligned with the PBS polarization. Then, to get the maximum power we had to tilt the half WP of 22° for the H and 18° for the L.
Finally we checked the extinction through half WP and PBS for H and L.
- For H : max 75 mW min 5 mW. Ratio 6.66%
- For L : max 70 mW min 4 mW. Ratio 5.7%
Right after Koheras : max 3.5 mW min 47 uW. Ratio 1.3%
|