Yaochin and Yuhang

(Actually, we started to do this since last Friday)

After realizing the importance of this work, we started to move the two lenses between OPO and AMC. After reaching a matching level of 98.5%, we found the beam on the second lens is quite off-center. We know that this will cause the problem of astigmatism(see attached figure). So we should try to avoid this. However, actually, this is caused by the alignment of homodyne BS and dichroic mirror just after OPO.

For the homodyne BS, we adjust its pitch and yaw to balance homodyne. The consequence of this adjustment is that we need to tilt BAB in order to overlap it with LO.

For the dichroic after OPO, we forgot to change it back to flat after the characterization work of its loss. Then it may tilt the beam as well.

To correct these two things, we did again the check of beam flatness from OPO to homodyne. And at the same time, we changed the PBS after OPO to a normal mirror.

(This work is still going on)