This morning we have checked and sligthly adjusted the polarization at the input of the pick off fiber.

We found that the buzzer used to inject some acoustic noise in the fiber was probably spoiling the measurement we did last time.

We aligned the output connector of the pick-off fiber so that the polarization in an optimal case should be s. Then we installed a polarizer

and minimized its transmission by adjusting the polarization at the input of the pick-off fiber.

We will ook at the data to check if the PC reference beam is now more stable in that condition.