R&D (FilterCavity)
YuhangZhao - 10:14, Tuesday 24 July 2018 (911)
The characterization of beam going out from Green Mode-cleaner

Yesterday, we measured the Green Mode-cleaner output beam. While measurement, I found the lock of green mode cleaner is more stable for half fringe. However, the lock we did last week is only for fringe higher than half fringe. If we lock it on half fringe we will have less power transmitted but more stable. However, I should say that even with half-fringe lock, the lock can be destoried by vibration. So maybe we should consider to put some rubber under the MZ to isolate the vibration.

Anyway, by locking the beam many times. I must say here that the measurement is performed with different locking condition. Although I tried to make the lock the same, I cannot make sure they are exactly the same. But the result is fine. I attached the figure here.

Images attached to this report
911_20180724031401_figure1.png
Comments related to this report
YuhangZhao - 19:49, Thursday 02 August 2018 (933)

Last time I used the wrong set up of the beam profiler. This time we used a correct one. The result is attached. The beam is not a round shape in this measurement. And I found the beam is shaking  while measurement.