I moved stuff on the PSL table to accommodate the PMC ringdown setup.
I used the beam that leaks from the steering mirror at the PMC transmission that was dumped to a razor blade dump. I installed a Y1 to steer the beam to the ringdown PD. Power in the beam 75mW.
I am guessing that 75 mW will burn / destroy any Thorlabs PD. I hope that mW is supposed to be uW.