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Message ID: 61     Entry time: Mon Feb 8 22:03:32 2010
Author: Frank 
Type: Laser 
Category: RC noise 
Subject: new results 

everything is back, pointing is much much less, power modulation too, ugf of the other loop is much higher - but nevertheless the performance is not much better, only one order of magnitude. it turns out that the noise is limited by the existing FSS stuff. tuning the gains (common, fast) can produce almost any shape and level (see graph), except much lower levels are not possible, at least not for more than a couple of seconds before everything starts to oscillate. so i will to debug the old FSS stuff first to see whats going on there. will try to investigate the noise of the FSS loop and maybe replace the VCO by a function generator and probably the RF photodiode to see if that changes something. Those can be exchanged easily without changing to much...

refcav-noise_2010-02-08.png

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