NAOJ GW Elog Logbook 3.2
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.
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.