Minutes of Meeting
November 2nd, 2016
Participants: M. Barsuglia, E. Capocasa, R. Flaminio, Y. Guo, M. Tacca

1. Coating at LMA
Discussion on going.

2. Optical scheme
New optical scheme produced by Matteo and Eleonora.

2a. Which polarization shall we use? The OPO and the SHG seems to work with S-pol (TBC with
Matteo Leonardi). Which polarization one is compatible with the EOM that we have?
Yuefan wil check.

2b. SHG lock. It can be done in transmission. GEO did it in transmission. Virgo is doing
it in reflection. If so we can remove the optics to do the lock-in in reflection.

2c. Share of IR power between SHG path and 1064IMC path? Need to check with Matteo Lombardi
what is the minimum power required for the SHG.

2d. Modulation frequency for the SHG/1064MC: GEO was using 75MHz. Virgo is using 80 MHz.
We are planning to use 15 MHz.

2e. IMC's. Mechanical design received form JP Zendri. Finesse: 500? Polarization: S?
Raffaele will consult with Matteo Lombardi. APC team will consult with people at LKB.

2f. Telescopes. Now that the optical lenght are fixed, telescopes can be studied.
Yuefan is studying the telescope for the SHG. Matteo Tacca will pass to Yuefan
the information about three lenses telescopes.

3. Window on vacuum chamber
Flange size is about 15 cm
KAGRA design received from Akutsu. With KAGRA design max window size will be ~9cm.
Matteo Tacca will ask Virgo design for same type of flange.

4. Optical table height. Tatsumi is investigating possible solutions to ahve the beam height
at the same height as the window on the vacuum chamber.

5. Visit to NAOJ of Matteo Tacca. Goal of visit will be the set-up of the green path
for the filter cavity control and the injection into the OPO. Need to define the list of
components to be bought.