Fit beam waist going to FC - NEW measurements

[Eleonora P., Yuhang]

We measured accurately the size of the beam that will go inside FC and we extimated the parameters of this beam.
We checked the locking of the PLL (ML and ppol) for each point, we used the fork to fix the camera on the bench, we tried to make the beam going as straight as possible inside the camera.

Parameters from the fit (fig 1) of the data are:
for W direction
-z0 = (14.8 +/- 0.8) cm --> distance from PBS
-z0 = (14.8 + 35)cm = 59.8 cm --> distance from OPO
-w0 = (126 +/- 3) um

for V direction
-z0 = (14.8 +/- 0.5) cm --> distance from PBS
-z0 = (14.8 + 35)cm = 59.8 cm --> distance from OPO
-w0 = (126 +/- 2) um

Parameters from the simulations, considering different positions z OPO-lens (since we are not sure about waist beam position inside the OPO):
for z = 0.13 m (fig 2)
-z0 = 59 cm --> distance from OPO
-w0 = 124 um

for z = 0.127 m (fig 3)
-z0 = 56 cm --> distance from OPO
-w0 = 113 um

for z = 0.135 m (fig 4)
-z0 = 52 cm --> distance from OPO
-w0 = 98 um

The results are good.

Next step:
- Telescope before FC