Rahul, Jennie W, Keita

Just catching up on historical alogs

We increased the dither amplitude to 1Vpp to give us better coherence in our horizontal input dither -> PD array RIN measurement compared to our previous alog (#87140).

We got pretty good coherences on PDs 2,3 5 -8. All of these measured between about 0.1 per m and 30 per m RIN.

After showing the results to Keita he got us to do two more measurements where we changed the input alignment yaw either side of the nominal to see if this had the expected results on the magnitude and phase of the transfer function.

The results are shown in the attached graphs, PD number is on the x axis and Magnitude, phase and coherence of each measurement are on the 3 y-axis. The measurements with the input aligned are shown in blue.

To get the two other measurements I looked at the two leeft-most diodes on the array (I think these are 4 on the top and 8 on the bottom) with the beam viwer as Rahul moved the PZT steering mirror in yaw.

For these three measuremenrts Keita pointed out that the discrepancy between the diodes phases didn't make much sense.