[Eleonora P, Yuhang]

Considering the beam parameters of entry #1133, we made the first simulation (using Jammt) for the IR injection telescope. In this simulation (fig 1) we put only two lenses in the straight path on the bench before the FC.

We set as initial position the one of PBS. 

Initial beam parameters (entry #1280):

z0 = 15 cm

w0 = 126 um

Resulting beam parameters (entry #1133):

z0 = 4,2673 m

w0 = 1032,7 um

The problem is that this solution is not robust, so there is a large mismatch as function of the position of the lenses of the telescope.

This is shown in fig 2 moving of +/- 5mm the 1st lens and in fig3 moving of +/- 5mm the 2nd lens.

Another problem is that with this configuration we are using the same two mirrors for the FC and homodyne alignment. 

Next step:

- extend the optical path before FC using 4 mirrors: good for alignment, bad for losses

- do again the simulation