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Message ID: 933     Entry time: Fri Aug 13 18:22:04 2010
Author: Jenna 
Type: Laser 
Category: GYRO 
Subject: Successful PLL 

After we got both sides locking properly and not oscillating anymore (as I put in the last post), we swapped from using the Marconi to drive the AOM back to the Tektronix (because we only have one Marconi), and immediately the noise in the spectrum analyzer looked worse. We took this signal and mixed it with the Marconi, and with the modulation switched off on the Tektronix, we looked at the beat frequency on a scope and minimized it. Then we turned on the PLL feedback to the Marconi, and now the error signal is a flat line. We turned the modulation on again to the Tektronix, and we can see a varying output signal which is our gyro signal, which is plotted below.

The calibration for this plot is 6.103e-4 V/count * 100kHz/V * lambda*S/(4A) * 2pi (rad/s/Hz) = 5.1686e-4.

DYM - Handshake:  If you open the plot in preview (on a mac), and then save it as a pdf over itself, it associates a png file with it automatically, which acts as a thumbnail.

Attachment 1: gryo_transmission.pdf  40 kB  Uploaded Mon Aug 16 01:07:07 2010  | Hide | Hide all
gryo_transmission.pdf
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