MichaelR and RickS

Today we leveled the FSS path beam at the 10 cm optical height (centered on lenses and irises).
The mount for the AOM does not allow it to go low enough with the beam level, so we replaced it temporarily with the eLIGO AOM mount sitting on 1" spacers.  We will modify the aLIGO mount and replace it ASAP.

We set up the FSS path to use the frequency upshifted beam and adjusted the alignment to get the following powers with the VCO mod level set at Max (32767):
47 mW incident on the AOM
33 mW in single pass (upstream of curved mirror M25)
20.5 mW double pass (downstream of PBSC and first turning mirror M26)

42% double pass efficiency.  Not great. We did not check the beam size at the AOM or the RF power delivered to the AOM.

We installed irises in both the single-pass and double-pass paths to block the unwanted diffraction orders.