During the reboots I took the opportunity to have another look into the OAT RefCav in the optics lab.

I removed the 50/50 beam pslitter infront of the RF LSC diode, so now ~30 mW of power is incident. In addition in optimised the HWP infront of the PM to reduce the AM, 2f_sb = < -80dB.

The few irises in the beam path are closed down, I looked with the viewer and reduced the iris so it was just not clipping.

I didn't find a low enough ND filter to o the paracitic interfernce hunt.

The cavity locks stable with a UGF ~300kHz, the settings are

The Laser temperature on the controller displays: T+40.991, the slow output (T-ed to the laser slow input and the oscilloscope) is at -620 mV.

Once we get the cavity locked again we can see if we gained anything.