[Craig, Elenna]

Craig and I input 2, 4, 6, 8, and 10 W of power from the IMC with the PRM aligned to get measurements of the shot noise on the ASC REFL WFS. This is a follow up of past ASC WFS measurements (alog 62473) that indicated we are not shot noise limited. DC centering was on during these measurements.

These are the DC counts on REFL A and B DC that I used to calculate the shot noise.

REFL_A_2W = 8200 ; % cts
REFL_B_2W = 8000 ; % cts
REFL_A_4W = 16200 ; % cts
REFL_B_4W = 16000 ; % cts
REFL_A_6W = 24000 ; % cts
REFL_B_6W = 24000 ; % cts
REFL_A_8W = 32000 ; % cts
REFL_B_8W = 32000 ; % cts
REFL_A_10W = 39400 ; % cts
REFL_B_10W = 40000 ; % cts

The RF chain follows a similar calibration to alog 62473 (linked above), but with different whitening gain:

REFL_A_RF45_gain = 9 ;
REFL_B_RF45_gain = 9 ;
REFL_A_RF9_gain = 15 ;
REFL_B_RF9_gain = 15 ;

This is in addition to a new 6 dB gain step on all channels added to compensate for the saturation at high power.

I think these plots reinforce the previous calculations and show that we are dark noise limited in the ASC REFL WFS.