This alog only includes settings that worked and quick transfer functions. Still working on the noise budget
Here's the original scheme we are using now https://dcc.ligo.org/DocDB/0150/E1800057/002/E1800057-v2.pdf
TTFSS
After we found the HV was off this morning everything else worked fine. Daniel got the Beckhoff auto locking to work again. The UGF can be pushed to 250kHz until it started to run into some weird notches and bumps. From the RF transfer function it almost seems like there's a zero at ~~500kHz. We are back to using a PFD TTFSS for this scheme (S1700331).
OPO
The UGF can't be pushed much beyond 1kHz as it would ring up 15kHz line and harmonics. Which means we can't engage 20/2000Hz boost. 6kHz notch (slow option) is used. 80MHz LO and OPO refl RF signal is now sent to OPO common mode board. The slow output goes to PZT driver (CH3 I think). PDH Vpp is 222mV at 0.5mW input to the OPO.
CLF
Nothing changed here. I just wanted to include the setting. I only pushed UGF to ~1kHz since low power CLF is mostly limited by sensing noise beyond 1kHz. The best CLF power to operate with OMC is to be determined (another overdue alog).
LO
Fast output of LO common mode board now goes to the 79.2MHz VCO (that eventually hooked up to the frequency doubler). Now that both OPO and laser PZTs are in-loop in order to adjust the laser frequency so that beat note freq - (2 x IMC VCO freq) = 0 (for 3 MHz locking) the only knob I found work was to adjust the VCO offset itself.
