Yesterday, Sheila and I gathered the information on the measurements of seed mode (see 43084), and got the conclusion that the seed waist is 556um at 3m before the upper periscope mirror.

Then I measured the beam mode profile coming out from the LO fiber coupler, which is divergent with waist 188um at 1.12m before the fiber coupler (Beam fitting as attached.)

If the estimation from the measurements is good enough, a potential mode matching solution is shown as below (I hereby copied the layout and labels from LLO):

• UPM/LPM = Upper/Lower Periscope Mirror
• L0: FL = 0.667m
• L12: FL = 0.445m; L13: FL = -0.334m
• L14/15: ROC = +50; FL = 0.1112m (already installed before, info from label)
• Positions of M13,14,15,16 and BS are only illustration, not precise positions yet. These can be adjusted according to the space on table, and will be updated later.
• The x-axis is in meter. 

For future use, I attached the alm matlab code of the mode matching solutions that can reproduce the graphs. 

• The UPM is at 3m, and the fiber coupler is at 1.2m, these are fixed points to start. (The 0 is tricky due to some restrictions of the code.) 
• Please follow the relative positions after the UPM and fiber coupler.

I will begin to install lenses and place them to rough positions without the seed beam.

I found that the Homodyne filters have already been added, including anti-whitening and calibration ones.