Dan, Alexei, Thomas
This was about work done last night but I pushed backspace on my aLOG... you know the rest.
We took a beam profiler (nanoscan) to measure AS_AIR with the SRM CO2 and SR3 RoC heaters on/off to measure the beam size change at various powers. Also we measured the full beam profile of AS_AIR with the SRM CO2 Laser on/off and will fit the q-parameter to try and guess the relative gouy phase of the acutators.
We also scanned the OMC PZT and found that the mode matching increased from 90% to ~99%. Alexei will post the detailed analysis using his omc_scanalyzer scripts.
We're still in the process of analyzing the data but here's some of the preliminary results from when we are ramping the SRM heater power from 0 to ~800mW.
The profile of the AS_AIR beam with SRM heater on (800mW) and off
The SRM lens appears to be producing a beam that isn't very gaussian. We believe we are well aligned when we took this profile. The AS_C yaw and pitch doesn't change when the SRM heater is switched on and off.
Movie of the OMC mode scan
Highlighted are the 0th, 1st and 2nd order peaks. Bottom plot shows the 1st/0th and 2nd/0th ratios. The 2nd order peak is being reduced as we ramp the SRM heater power from 0 to 800mW. However we get some increase in the 1st order peak. Likely the odd shaped beam we are generating as seen above.
Ratio of HOM plot
Height of the TEM00 peak as we ramp the power. Overall the transmitted power through the OMC is improved as we increase the SRM lens