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Entry  Fri Oct 29 15:34:36 2010, Zach & Koji, Laser, GYRO, CCW loop characterization bart-simpson-generator.png
    Reply  Sat Oct 30 20:02:01 2010, Koji, Laser, GYRO, gyro characterization Oct 27, 2010 (1) open_loop_primary.pdf
       Reply  Sat Oct 30 20:18:06 2010, Koji, Laser, GYRO, gyro characterization Oct 27, 2010 (2) error_primary.pdffeedback_primary.pdf
          Reply  Sat Oct 30 20:57:19 2010, Koji, Laser, GYRO, gyro characterization Oct 27, 2010 (3) error_secondary.pdf
             Reply  Sat Oct 30 22:49:04 2010, Koji, Laser, GYRO, gyro characterization Oct 27, 2010 (4) 
                Reply  Sat Oct 30 23:41:31 2010, Koji, Laser, GYRO, gyro characterization Oct 27, 2010 (5) 
Message ID: 1121     Entry time: Sat Oct 30 23:41:31 2010     In reply to: 1120
Author: Koji 
Type: Laser 
Category: GYRO 
Subject: gyro characterization Oct 27, 2010 (5) 

[Zach / Koji]

Other things to do:

Assemble the noise budget plot

  • Put every possible thing into the noise budget plot
  • Propose other noise measurements

Tuning of the secondary loop

  • Take the thorough alignment of the beams
  • Record the improvement of the transmited power by the alignment improvement.
  • Adjust the openloop gain of the secondary loop
  • Measure the new error / feedback signals.

CDS preparation

- At least the following stuffs for each loop are needed to be connected to the CDS system in order to make the characterization continuously:
(ADC)

  • The error signal (or input monitor)
  • TP2 or TP6 (= the signal before the summing point)
  • output monitor (= the signal after the summing point)
  • Reflection DC
  • Transmission DC
  • and Gyro beat signal

(DAC)

  • PZT sweep input

- Consider the whitening filters to amplify the signal above the ADC noise level.

Circuits

- Confirm the circuits and make the latest circuits diagram.

- Measure the latest filter TF. If we already have it, put the numerical data / the liso model somewhere.

- Measure the input equivalent noise of the filter. 
i.e. short the input of the filter box measure the outupt noise of the box (or the notch). Divide it with the TF to convert it
to the input equivalent noise.

- Measure the demodulator noise levels.

- Shot noise characterization: put DC light onto the PDs and measure the demodulator noise with various DC powers.


It is done for now.

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