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Entry  Mon Dec 20 14:35:23 2010, tara, Notes, Electronics Equipment, adjusting polarization for 35.5 MHz EOM 
    Reply  Mon Dec 20 22:52:55 2010, rana, HowTo, PMC, nuts 
       Reply  Thu Dec 23 22:26:14 2010, rana, HowTo, PMC, nuts 
Message ID: 436     Entry time: Mon Dec 20 14:35:23 2010     Reply to this: 438
Author: tara 
Type: Notes 
Category: Electronics Equipment 
Subject: adjusting polarization for 35.5 MHz EOM 

Last week I accidentally changed the polarization of the beam to the 35.5 MHz EOM. So I optimize it again to minimize an RFAM effect.

I used the signal of the transmitted beam behind RCAV on the PD for beat signal. Since the cavity pole is around 37 MHz, I should be able to see the

signal at 35.5 MHz easily. I connected the RF signal from the PD to a spectrum analyzer and adjusted the 1/2 wave plate to  minimize the peak at 35.5 MHz.

However I also notice two peaks at 35.29 and 35.71 MHz (35.5 +/- 0.21 MHz) which are approximately the same size as the 35.5 MHz peak.

I'm not sure where they come from.

 

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