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ID Date Author Type Categorydown Subject Text Attachments
  11361   Mon Jun 15 22:36:40 2015 rana, kojiUpdateGreen LockingBeatBox Assay: not looking goodBecause the ALS beatbox schematic is out-of-date
and misleading, we pulled the box to photograph
the current implementation and figure out
  
  11363   Fri Jun 19 01:24:26 2015 rana, kojiUpdateGreen LockingBeatBox Assay: not looking goodWe had decided a few days ago, to bypass
the IF part of the BeatBox board and put
some of the Haixing Maglev generic filter
  
  11364   Fri Jun 19 01:55:35 2015 ericqUpdateGreen LockingBeatBox Assay: not looking good


  
  11604   Wed Sep 16 03:37:06 2015 KojiSummaryGreen LockingWorkable delay line setup prepared[Koji Gautam]

The variable delay line has been
setup for practical use. The hardware and
 6x 
  11715   Mon Oct 26 19:10:59 2015 gautamUpdateGreen LockingAUX PDH loop characterizationI began my attempts to characterize the
PDH loops at the X end today. My goal was
to make the following measurements:
  
  11865   Tue Dec 8 23:24:08 2015 gautamUpdateGreen LockingY end laser (Lightwave) PZT calibrationSummary:

I
measured the PZT actuator gain for the Lightwave
 Ycalib_8Dec.pdf 
  11877   Sun Dec 13 21:55:28 2015 gautamUpdateGreen LockingY end laser (Lightwave) PZT calibrationSummary:

After
the discussions at the Wednesday meeting,
 IMG_5972.JPGServoY_TF_13Dec2015.pdfDatanCode.zipPSD_916Hz.pdf 
  11879   Mon Dec 14 16:27:11 2015 gautamUpdateGreen LockingY-end AUX PDH noise breakdownSummary:

I've
attached the results from my measurements
 YAUX_NB_Dec2015.pdfPDH_errSig_Calib.pdf 
  11887   Wed Dec 16 18:34:40 2015 gautamUpdateGreen LockingGreen beat channels temporarily set up as IR beat channelsSince there
are a few hours to go before the locking
efforts tonight, I've temporarily borrowed
  
  11888   Wed Dec 16 23:15:28 2015 ericqUpdateGreen LockingGreen beat channels temporarily set up as IR beat channelsWith the IR beats going to the nominal
ALS channels as Gautam left them, we're
able to measure the free running frequency
 2015-12-16_AUXfreerunning.pdf 
  11906   Mon Jan 4 16:09:54 2016 gautamUpdateGreen LockingY end laser (Lightwave) PZT calibrationSummary:

I
redid this measurement and have now determined
 choosingExcFreqs.pdflaserPZTcalib.pdf 
  11907   Mon Jan 4 16:45:11 2016 gautamUpdateGreen LockingY-end AUX PDH noise breakdownSummary:

I've
re-measured the noise breakdown for the Y-end
 ErrSigBreakdown.pdfcontrolSigBreakdown.pdfYEnd_PDH_OLTF.pdf 
  11936   Tue Jan 19 17:27:58 2016 gautamUpdateGreen LockingAUX X power investigationsLast week, Eric and I noticed that the
green transmission levels at the PSL table
seem much lower now than they did a month
 X_END_POWER_BUDGET.JPG 
  11944   Fri Jan 22 11:33:20 2016 gautamUpdateGreen LockingAUX-X AM/PM investigationsI was trying to characterize the AM/PM
response of the X end laser. I tried to measure
the AM response first, as follows:
 AUX_X_AM.pdfAUX_X_RIN.pdfNE_Mephisto.png 
  11945   Fri Jan 22 13:33:37 2016 ericqUpdateGreen LockingAUX-X AM/PM investigations


  
  11946   Fri Jan 22 17:22:06 2016 gautamUpdateGreen LockingAUX-X AM/PM investigationsThere were a number of directories in /users/OLD/mott/PZT/2NPRO,
I've used the data in Innolight_AM_New.
Also, I am unsure as to what their "calibration"
 AM_response.pdfNE_investigations.pdf 
  11947   Fri Jan 22 18:46:03 2016 ranaUpdateGreen LockingAUX-X AM/PM investigationsThe PDA photodetectors are DC coupled,
so you cannot use them to go directly into
the analyzer. Must use the DC block so that
  
  11951   Tue Jan 26 17:50:22 2016 gautamUpdateGreen LockingLightwave frequency noise measurementI attempted to measure the frequency noise
of the extra Lightwave NPRO we have that
is currently sitting on the PSL table. I
  
  11953   Wed Jan 27 18:19:45 2016 gautamUpdateGreen LockingLightwave frequency noise measurementAfter adjusting the alignment of the two
beams onto the PD, I managed to recover a
stronger beatnote of ~ -10dBm. I managed
  
  11956   Thu Jan 28 00:29:30 2016 gautamUpdateGreen LockingLightwave frequency noise measurementSummary of the work done today:

Alignment and other work on
PSL table
 PLL_OLG.pdfFreq_noise_comparison.pdf 
  11961   Fri Jan 29 14:43:47 2016 SteveUpdateGreen LockingInnolight laser is 10 years old


 inno1W.pdf 
  11962   Fri Jan 29 16:55:27 2016 ranaUpdateGreen LockingInnolight laser is 10 years oldI don't think there's any evidence
that the noise eater is bad. That would change
the behavior of the relaxation oscillation
  
  11963   Sat Jan 30 00:12:22 2016 gautamUpdateGreen LockingInnolight laser is 10 years old 




 RIN_comparison.pdf 
  11964   Sat Jan 30 09:56:24 2016 KojiUpdateGreen LockingInnolight laser is 10 years oldIt is strange that there is no difference
between with and without NE, isn't it?
  
  11967   Mon Feb 1 15:16:28 2016 gautamUpdateGreen LockingInnolight laser is 10 years oldThe Innolight laser control unit has a
25 pin D-sub connector on the rear which
is meant to serve as a diagnostics aid, and
  
  11968   Mon Feb 1 15:43:18 2016 KojiUpdateGreen LockingInnolight laser is 10 years oldThis is the same one as what you got from
Steve. But you can find full pages.

https://wiki-40m.ligo.caltech.edu/PSL/NPRO
  
  11969   Mon Feb 1 18:11:25 2016 gautamUpdateGreen LockingLightwave frequency noise measurementBefore distrubing the beat setup with the
spare Lightwave laser, I wanted to see if
I could resolve the apparent difference in
 Free_running_frequency_noise_comparison.pdf 
  11970   Tue Feb 2 18:35:47 2016 gautamUpdateGreen LockingLightwave NPRO moved from PSL table to SP tableI've moved the following components
that was a part of Koji's setup from
the PSL table to the SP table so that I may
  
  11971   Tue Feb 2 18:54:02 2016 KojiUpdateGreen LockingLightwave NPRO moved from PSL table to SP tablejiIn fact, it is one of the most difficult
type mode profiling to measure a beam directly
out from a laser source.
  
  11973   Wed Feb 3 23:23:47 2016 gautamUpdateGreen LockingLightwave NPRO moved from PSL table to SP tableAs Koji pointed out in the previous elog,
the CCD beam profiler was ill suited for
this measurement. Nevertheless, to get a
 KnifeEdgeScans_x.pdfBeamscan_x.pdf 
  11974   Thu Feb 4 09:16:46 2016 KojiUpdateGreen LockingLightwave NPRO moved from PSL table to SP tableI don't think the discrepancy is a
serious issue as long as the mode is clean.
The mode is determined by the NPRO crystal
  
  11977   Fri Feb 5 00:23:01 2016 gautamUpdateGreen LockingLightwave NPRO moved from PSL table to SP tableI've repeated the measurement for the
x-direction and also did the y-direction,
taking into account Koji's suggestion
 Beamscan_setup.pdfBeamscan_x.pdfBeamscan_y.pdfZscan.pdf 
  11978   Fri Feb 5 15:02:13 2016 gautamUpdateGreen LockingX-end NE cable[Steve, gautam]

Steve thinks that the X-end Innolight
does not come with the noise-eater option
  
  11979   Fri Feb 5 16:50:24 2016 gautamUpdateGreen LockingFirst pass at mode-matchingI've done a first pass at trying to
arrive at a mode-matching solution for the
X-end table once we swtich the lasers out.
 Modematch_AUXx.pdfNewSetUp.pngModematch_AUXx_2.pdfXendModeMatch.m.zip 
  11981   Mon Feb 8 15:36:37 2016 gautamUpdateGreen LockingAlternative mode-matching schemeI looked in the optics cabinet to see what
lenses we have available, and re-ran the
mode-matching calculation to see if we could
 Modematch_alternative.pdf 
  11982   Tue Feb 9 04:37:10 2016 ericqUpdateGreen LockingLaser swap initiated[ericq, Gautam]

Tonight we embarked on the laser
swap. In short, we have gotten ~210mW through
  
  11983   Tue Feb 9 11:49:47 2016 gautamUpdateGreen LockingLaser swap initiatedSteve pointed me to an old
elog by Zach where he had measured the
waist of the 1W Innolight NPRO. I ran
 Innolight_beamProfile.pdf 
  11984   Tue Feb 9 19:15:36 2016 gautamUpdateGreen LockingLaser swap - updatesSome updates on the laser swap situation:


Mode-matching calculation: 



I
should have caught this earlier, but it was
 Modematch_X.pdfXendModeMatch.m.zip 
  11985   Wed Feb 10 17:57:15 2016 gautamUpdateGreen LockingLaser swap - updatesAfter the discussion at the meeting, I
decided to go ahead and open the top of the
oven so that I could get a visual on where
  
  11987   Fri Feb 12 11:10:49 2016 SteveUpdateGreen LockingInnolight laser is 10 years oldIt shipped out for repair evaluation.

Arrived to Hayward,CA   2016Feb16

 
 inno1W.jpg 
  11988   Fri Feb 12 17:05:40 2016 gautamUpdateGreen LockingLaser swap - green light recovered but no flashes in the armAfter carefully tweaking the mode-matching
of the IR into the crystal and the four-axis
translation stage on which the doubling oven
  
  11989   Fri Feb 12 19:07:52 2016 KojiUpdateGreen LockingLaser swap - green light recovered but no flashes in the arm800e-6 / 0.225^2 = 0.016

=> 1.6%/W

I thought Kiwamu had roughtly 2%/W.
  
  11999   Fri Feb 19 00:42:19 2016 gautamUpdateGreen LockingLaser swap - beam ellipticity from laser?Eric and I spent some time yesterday night
trying to recover the green in the arm after
the laser swap. The problem essentially was
 IMG_6287.JPGIMG_6288.JPGIMG_6286.JPG 
  12002   Mon Feb 22 13:56:52 2016 gautamUpdateGreen LockingLaser swap -reflected beam from ETM alignedI tried aligning the green beam, elliptical
as it is, to the arm by using the various
steering mirrors after the doubling oven.
  
  12006   Tue Feb 23 23:01:16 2016 gautamUpdateGreen LockingLaser swap - Green PDH lockingGiven that we were seeing green flashes
in the arms, I tried to see if I could get
the green locked to the arm in a nice mode.
 AM_scan.pdfAM_scan_zoomed.pdf 
  12009   Wed Feb 24 19:29:13 2016 gautamUpdateGreen LockingLaser swap - Green PDH lockedAfter the discussion at the meeting today,
I decided to try and lock the green by sweeping
through PZT dither frequencies in the vicinity
  
  12012   Fri Feb 26 01:52:44 2016 gautamUpdateGreen LockingLaser swap - Green PDH OLTFI spent some more time today trying to
optimize the modulation frequency and amplitude
for the X end PDH, and the alignment/mode-matching
 X_PDH_OLTF_20160225.pdf 
  12013   Mon Feb 29 17:17:26 2016 gautamUpdateGreen LockingLaser swap - still no green beatnoteI continued the hunt for a green beatnote
today - I decided to take the output from
the RF amplifiers sitting on the PSL table
  
  12016   Wed Mar 2 17:42:19 2016 gautamUpdateGreen LockingLaser swap - some progress[Koji, Johannes, gautam]

With Koji's and Johannes'
help, I managed to resolve the coupling the
  
  12017   Thu Mar 3 01:25:50 2016 gautamUpdateGreen LockingLaser swap - 2 IR + 1 green beatnotes found[ericq, gautam]

Summary of work done tonight:


The PDH setup at the Y-end
 IR_beat_20160303_2.pdf 
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