Rick, Dripta & I went into the PCAL lab to setup the PCAL lab for responsivity ratio measurements again.

We installed refl and trans mirrors and aimed the beam at the center of the Apatures on PS4 & PS5.
We also touched up the AOM to see if we can get rid of satelite beams around an iris inside the TX module.

The AOM was swapped out due to the old one (S.N. 124001) having what looks to be a crack in the outside of the AOM.
New AOM ( S.N. 125715 ) was put in it's place and aligned.
We then measured the input power before the AOM : 1.9 W
Then measured the First Order max diffracted power : 1.45 W
then measured the Zero Order power with the power to the AOM OFF: 1.85 W
So the new Diffration Efficiency is First Order / Zero Order: 78.4 %
The AOM Tx : Zero order / Input:  76.3%

We then Checked the BS power on the Trans beam using the High power head to get 333mW.
Then the Refl beam was 335 mW.

We then tuned up the OFS.
New OFS gain  is 5.62V
new OFS Loop Offset : 4.00V

Unity Gain Frequency : 61.5 khz
40 degrees of Phase margin
46 dB @ 100hz