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Message ID: 53     Entry time: Fri Feb 5 21:10:48 2010
Author: Frank 
Type: Laser 
Category: RefCav 
Subject: new PD for frequency-shifted power detection 

added a detector behind the curved mirror to measure the changes in deflected power (1.order) while changing the frequency of the VCO. PD is a large area Si diode to reduce pointing effects. Signal is connected to QPD-SUM instead of the QPD signal (QPD channels for x and y still connected and valid, only sum disconnected !!). We didn't trust the sum anymore as we can see slightly pointing related changes there as well.

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