Today we made progress on the work to minimize polarization noise in the fiber optic circuit for the squeezer installed in the rack in Figure 1 in the atrium
- We have improved the alignment of the polarization to the fast axis of the PM fiber that carries the pick of from the detection to the atrium (acting on the l/2 and l/4 plates as described in entry #67833).
- We have minimized the ellipticity of the polarization exiting the squeezing fiber during heating with a heat gun. This required optimizing the mating connections in the first junction box (figure 2) which is located at the bottom of the rack This required testing several different mating and two different fiber splitters. We also had a burn at the output of fiber exit from the injection. This required polishing the fiber with polishing sheets.
- We replaced the 10 meter long Thorlabs PM fiber between the first ("out0" in figure 2) and the second ("SQZ and phase cam" in figure 3) splitting boxbox with a 2 meter long OZ PM fiber
In the end we achieved a good result up to the fiber output connected in the ''split box' (see entry #67833 and figure3). The optimization of the alignments beyond this box will be continue in a future shift.
