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The ISS measures the power fluctuations on a photodiode placed after the [[Mach Zender]], but before the [[Mode Cleaner]], and tries to servo that signal to zero. <<TableOfContents>>
<<BR>>

= NEW ISS =
== Photo detector ==
No real photo detector has been installed yet for the ISS.

== AOM ==
A new AOM has been installed before the PMC in the Summer of 2011.
However this is AOM wasn't yet activated, so the PSL beam just goes through
the AOM without any modulations.

 . ''' AOM datasheet ''' [[attachment:AOMdatasheet.pdf]]

<<BR>>
<<BR>>
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= OLD DAYS =
The ISS measures the power fluctuations on a photodiode placed after the [[Mach Zender]], but before the [[Mode_Cleaner]], and tries to servo that signal to zero.
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== Schematic ==

 * [[http://www.ligo.caltech.edu/~fnocera/files/ISS%20rev%20D%20nov04.pdf|Schematic of 40m ISS servo]] - Beware that there are various "Revision D" ISS's floating around; this link is to the 40m version. There is a paper version of this at the 40m that is marked up with further modifications to the 40m ISS.
 * [[http://www.ligo.caltech.edu/~fnocera/files/PD%20Head.pdf|Photodiode schematic]] - This is from Flavio's website, though the direct link from his ISS page is broken due to a misspelling.
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|| C1:PSL-ISS_INSENPD_FW || Out-of-loop photodiode, whitened || || C1:PSL-ISS_INMONPD_FW || Out-of-loop photodiode, whitened ||


NEW ISS

Photo detector

No real photo detector has been installed yet for the ISS.

AOM

A new AOM has been installed before the PMC in the Summer of 2011. However this is AOM wasn't yet activated, so the PSL beam just goes through the AOM without any modulations.




OLD DAYS

The ISS measures the power fluctuations on a photodiode placed after the Mach Zender, but before the Mode_Cleaner, and tries to servo that signal to zero.

The ISS is AC-coupled, so its purpose is not to control long-term drift. In its nominal configuration, it has gain from 1-100,000 Hz. This is to suppress the intensity noise in our measurement band.

The ISS servo sits on the PSL table; its a beige box with black front and back panels. All of the hooks for doing fast loop measurements are on that box.

The ISS actuator is the Current Shunt in the MOPA box.

Schematic

  • Schematic of 40m ISS servo - Beware that there are various "Revision D" ISS's floating around; this link is to the 40m version. There is a paper version of this at the 40m that is marked up with further modifications to the 40m ISS.

  • Photodiode schematic - This is from Flavio's website, though the direct link from his ISS page is broken due to a misspelling.

DAQ channels

C1:PSL-ISS_INSENSPD_F

In-loop photodiode

C1:PSL-ISS_INSENSPD_FW

In-loop photodiode, whitened

C1:PSL-ISS_INMONPD_F

Out-of-loop photodiode

C1:PSL-ISS_INMONPD_FW

Out-of-loop photodiode, whitened

C1:PSL-ISS_CSDRIVE_F

C1:PSL-ISS_CSDRIVE_FW

PSL/Intensity_Stabilization_Servo (last edited 2020-08-06 22:55:40 by GautamvenugopalanATligoDOTorg)