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Entry  Tue Dec 6 02:57:44 2011, kiwamu, Update, Green Locking, 1st trial of handing off YarmALS.png
    Reply  Wed Dec 7 02:55:38 2011, kiwamu, Update, Green Locking, locking activity tonight 
Message ID: 6076     Entry time: Tue Dec 6 02:57:44 2011     Reply to this: 6080
Author: kiwamu 
Type: Update 
Category: Green Locking 
Subject: 1st trial of handing off 

I succeeded in handing off the servo from that of the ALS to IR-PDH.

However the handing off was done by the coarse sensor instead of the fine sensor because I somehow kept failing to hand off the sensor from the coarse to the fine one.

The resultant rms in the IR-PDH signal was about a few 100 pm, which was fully dominated by the ADC noise of the coarse sensor.


Tomorrow I will try :

  (1) Using the fine sensor.

  (2) Noise budgeting with the fine sensor.


Here is the actual time series of the handing off.


(Upper left ):  intracavity power.
            As the offset was adjusted the power increased to ~ 0.8. Eventually the power becomes close to the nominal value of 1 after the handing off.
(Lower left) : Frequency of the beat-note.
            After the engagement of the ALS servo, I was scanning the arm length and searching for the resonance by changing the error point of this signal.
(Lower right) : IR-PDH signal.
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