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Sun Jun 3 22:48:59 2018, johannes, Update, PSL, aux laser replacement
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Mon Jun 4 02:52:52 2018, johannes, Update, PSL, aux laser replacement
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Mon Jun 4 11:00:37 2018, gautam, Update, PSL, aux laser replacement
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Tue Jun 5 02:06:59 2018, gautam, Update, PSL, aux laser first (NULL) results
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Message ID: 13916
Entry time: Tue Jun 5 02:06:59 2018
In reply to: 13913
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Author: |
gautam |
Type: |
Update |
Category: |
PSL |
Subject: |
aux laser first (NULL) results |
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[johannes, gautam]
- Johannes aligned the single bounce off the ITM into the AUX fiber on the AS table, and also the AUX beam into the fiber on the PSL table.
- Mode matching isn't spectaular anywhere in this chain.
- But we have 2.6mW of light going into the SRM with the AOM deflection into the 1st order beam (which is what we send into the IFO) maximum.
- We set up some remote capabilities for the PLL and Marconi frequency (=PLL setpoint) control.
- Motivation was to try and lock DRMI, and look for some resonance of the AUX beam in the SRC.
- We soon realized this was a way too lofty goal.
- So we decided to try the simpler system of PRMI locked on carrier.
- We were successfully able to sweep the Marconi setpoint in up to 20kHz steps (although we can only move the setpoint in one direction, not sure I know why now).
- Then we decided to look for resonances of the AUX beam in the arm cavity.
- Still no cigar


- Plus points:
- PLL can be reliably locked remotely.
- Marconi freq. can be swept deterministically remotely.
- Tomorrow:
- Fix polarization issues. There is some low freq drift (~5min period) of the power incident on the fiber on the PSL table which we don't understand.
- Verify MM into IFO and also into fiber at PSL table.
- Do mode spectroscopy.
I was wondering why the PMC modulation sidebands are showing up on the control room analyzer with ~6dB difference in amplitude. Then I realized that it is reasonable for the cabling to have 6dB higher loss at 80 MHz compared to 20 MHz. |