We want there to be ~16000 cts of signal per quadrant on the optical levers. I think that most of the QPDs have been modified to have 100k transimpedance resistors.
From the attached 90 day trend, you can see that the ETMX, BS, PRM, and SRM are really low. We should figure out if we need to change the lasers or if the coating reflectivities are just low.
Steve, can you please measure the laser powers with a power meter and then reply to this entry?
Another possibility is that we are just picking a dim beam and a brighter one is available. |