peter.king@LIGO.ORG - posted 10:04, Tuesday 09 October 2018 - last comment - 16:52, Tuesday 09 October 2018(44429)
Reference cavity alignment tune up
Tuned up the alignment into the reference cavity. The transmission improved from ~2.2V to ~3V.
Removed the DC block from the AOM (see attached photo for the aftermath).
Measured the transfer function with the current gain slider settings. The UGF was ~452 kHz
with about 60 degrees of phase margin. Two measurements ar attached, one out to 2 MHz and the
other out to 10 MHz. No big changes were observed.
Images attached to this report
Comments related to this report
A quick note in passing, the cavity visibility is ~84% (1 - 80/500). The output of the locking photodiode was ~500 mV unlocked and ~80 mV locked.