40m QIL Cryo_Lab CTN SUS_Lab CAML OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
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ID Date Author Type Categoryup Subject Text Attachments
  1467   Tue Aug 5 14:54:36 2014 EvanDailyProgressopticBRDF of AlGaAs mirror 132 after cleaning


  1468   Tue Aug 5 18:10:31 2014 EvanDailyProgressopticAlGaAs mirror transmissions; optical contactingI used the ThorLabs power meter to get
the transmission coefficients for the five
AlGaAs mirrors.
  1471   Thu Aug 14 15:23:36 2014 Emily, EvanNotesopticAOM fiber noise cancellation  New
setup for fiber phase noise cancellation
  1472   Thu Aug 14 15:24:14 2014 Emily NotesopticTemporarily changed angle on half wave plate(Laser going to ACAV) I changed the angle
of the half-waveplate before the PBS in order
to increase the amount of power going into
  1486   Wed Aug 27 03:21:53 2014 ranaSummaryopticoptimization for ETM with a-Si/SiO2 coatings  I filled in more values for a-Si
at 120 K into the wiki
that Matt Abernathy set up. Then I ran
  1488   Thu Aug 28 17:36:03 2014 EvanDailyProgressopticMode-matching solution for north cavityCurrent configuration:

    Target waist: 180 µm,
z = 0 mm
    Lens 1: 140
  1489   Thu Aug 28 19:10:40 2014 EvanDailyProgressopticMode-matching solution for north cavity


  1503   Sat Sep 6 12:54:05 2014 Tara, EvanDailyProgressopticNorth photothermal TFTara and I took an SR785 measurement of
the north photothermal transfer function.
Clearly there's something wrong with
  1505   Sun Sep 7 19:33:40 2014 Tara, EvanDailyProgressopticNorth photothermal TFTara and I took another photothermal TF
of the north cavity today. Relevant parameters:

    Power incident on cavity:
  1506   Sun Sep 7 20:37:50 2014 Tara, EvanDailyProgressopticSome lens tweaksSome minor maintenance/improvements to
the optical setup:

    We replaced the existing
  1511   Thu Sep 11 00:47:14 2014 EvanDailyProgressopticSouth photothermal TFI took a swept-sine measurement of the
photothermal TF just as Tara and I did for
the north cavity. To get a better measurement,
  1512   Thu Sep 11 11:40:41 2014 EvanDailyProgressopticSouth photothermal TF


  1532   Sun Nov 16 23:32:49 2014 EvanDailyProgressopticNorth photothermal TFI believe the factor of π / F
here is an error. It should instead be the
transmission T. That lowers the absorption
  1550   Sat Jun 20 10:14:50 2015 EvanNotesopticcoating optimization for AlGaAs:electric field in coating layerI reran multidiel_rt with the as-built
coating structure. The penetration depth
is x0 =
  1551   Sat Jun 20 22:59:58 2015 EvanDailyProgressopticSouth Faraday isolator path reworkedI reworked the beginning of the south optical
path so that there are two steering mirrors
before the beam goes into the FI.
  1552   Tue Jun 23 20:37:22 2015 EvanDailyProgressopticPointing recoveredPointing into both cavities has been recovered.

I could not get the PMC on the
south path to lock, so I have just taken
  1553   Wed Jun 24 16:19:37 2015 EvanDailyProgressopticLocking recoveredI reinstalled the old, underpowered unipolar
HV supply that we used to use for the south
cavity. Since Aidan is going to redo the
  1594   Tue Oct 20 19:43:05 2015 Antonio/Aidan/EricDailyProgressopticOptics inventoryThe work that we need to do for the TCN
experiment is at the state where we cannot
easily go further without improving
  1649   Sat Jun 25 18:12:56 2016 AntonioDailyProgressopticNorth path construction progressNorth Path


The north path is going
  1651   Sun Jun 26 21:08:17 2016 AntonioDailyProgressopticNorth path construction progress: PMC MM lenses Summary

I have added two lenses in order
to create a waist of 330um for when the PMC
  1663   Fri Jul 8 22:09:33 2016 AntonioDailyProgressopticNorth path construction progress 2North Path

Following entry ID 1649, additional
  1670   Thu Jul 14 20:57:07 2016 AntonioDailyProgressopticSouth path construction progressSummary
Following ID 1649 we start the implementation
of the South cavity path.
  1799   Tue Jan 3 23:09:34 2017 awadeDailyProgressopticMoved FSS EOM backward 6 cmI was unable to remove a ~32 kHz ringing
from the north path lock. I thought possibly
that it might have to do with polarisation
  1974   Wed Nov 8 20:31:24 2017 awade, CraigDailyProgressopticReducing residual 14.75 MHz AM and some changes to the north path[awade, Craig]

Yesterday we went hunting for residual
AM from the PM phase modulators.  This
  2252   Mon Nov 12 11:53:50 2018 anchalNotesopticChanged half waveplate angle after South EAOMFor some reason after the weekend, I found
that the laser power on the south path decreased
by about 300 uW. On checking power with a
  1994   Thu Nov 30 12:02:05 2017 awade, CraigDailyProgressscatterInitial buzz test and cleaning of periscope mirrors and final MM lens--- This is a backpost
from last week ---
  2022   Tue Dec 19 22:44:48 2017 awadeDailyProgressscatterBuzz test of beat boardI used the buzzer to help locate sources
of scatter in the transmission beat board. 

Here I used the SR785 in swept
  2023   Thu Dec 21 08:58:39 2017 CraigDailyProgressscatterScatter Shoulder FitI've been learning about scattering
from here
and here. 
  2026   Thu Dec 21 18:57:12 2017 awadeDailyProgressscatterSwitch out final MM lens in North pathAs pictured in PSL:1994,
there was a burn mark in the center of the
final lens before the north reference cavity. 
  2028   Fri Dec 22 14:38:24 2017 awadeDailyProgressscatterFixed bad PDH error signalIt turns out that the bad PDH signal
caused by monitor daughter board (D040424)
note being properly seated in its plug. 
  2033   Sun Jan 7 17:53:26 2018 Craig, awadeDailyProgressscatterScattering Sources Probably From Inside VaccanTL;DR We have (1)
poor alignment of light into the cavities
and (2) ghost
  2036   Mon Jan 8 14:46:09 2018 CraigDailyProgressscatterNorth Cavity Transmission BackreflectionYesterday I optimized the North cavity
visibility for a long time, and achieved
around 60% visibility, which is pretty good
  2064   Mon Jan 29 20:22:06 2018 CraigDailyProgressscatterPre-Vent Vaccan Tranmission Scattering DrawingI drew the basic scatterers I see when
viewing the inside of our vaccan from the
transmission port with the IR viewer. 
  2084   Fri Feb 9 18:36:40 2018 awade, CraigDailyProgressscatterScatter dumping around FSS reflection PDsI
reinstalled the green glass dump in the north
cavity FSS REFL PD prompt reflection path. 
  2093   Thu Feb 15 18:45:35 2018 CraigDailyProgressscatterNeed more Black Glass Hexagonal BasesMade nine black glass hex beam dumps today. 
Only stopped because we ran out of hex bases. 
Need to order more.
  2127   Fri Mar 9 16:10:41 2018 Craig, awadeDailyProgressscatter500 Hz resonant scatter hump in beatnote ASDIf you look at our
beatnote ASD you can see a broad dirty
hump at 500 Hz.
  2128   Sun Mar 11 16:50:59 2018 Craig, awadeDailyProgressscatter500 Hz resonant scatter hump in beatnote ASDAfter buzzing the table with a probe at
500 Hz, the source of the 500 Hz resonance
is the first steering mirror after the PMC. 
  2135   Thu Mar 15 10:29:04 2018 awadeDailyProgressscatterAddressing 500 Hz scatter pickupGoing back the original issue of scattering,
it appears that there is light being back
reflected from somewhere in the post PMC
  2149   Wed Mar 21 00:40:01 2018 CraigDailyProgressscatterThe Sentinels: Transmission Table Black Glass Beam DumpsScattering is a huge problem in our setup,
and we aren't sure where exactly the
offending scattering is coming from. 
  2150   Wed Mar 21 11:07:17 2018 awadeDailyProgressscatterThe Sentinels: Transmission Table Black (Green) Glass Beam DumpsWhich direction are you trying to dump?
Into or out-of the can?

The scatter going inward is being
  2152   Fri Mar 23 15:12:00 2018 CraigDailyProgressscatterPowerpoint Trans Table DiagramThis diagram will be for quickly keeping
track of scattering beams/scattering resonances
on the trans table.  Need to improve
  2155   Wed Mar 28 11:29:19 2018 awadeNotesscatterHigher quality vaccan windows: 40m stock of wedged windowsI just checked the 40m's stock of wedged,
AR coated, optics in the pull out draws. 
  2156   Wed Mar 28 15:29:42 2018 KojiNotesscatterHigher quality vaccan windows: 40m stock of wedged windowsThat was unfortunate. But why does BK7
uncompatible with the purpose? We need UV
fused silica only for the high power reason,
  2158   Thu Mar 29 11:14:52 2018 awadeNotesscatterHigher quality vaccan windows: 40m stock of wedged windowsI guess BK7 is fine, we're not going
to be putting high power in.  I just
though UV fused silica would be better practice
  2172   Mon Apr 16 16:23:09 2018 awadeDailyProgressscatterBeam size on trans BN detectorI thought I'd have a look at how big
the beam is on the current 1811 New Focus
detector. Over focusing here might be a source
  2174   Thu Apr 19 18:28:11 2018 ranaDailyProgressscatterBeam size on trans BN detector This beam is
WAY too big for the PD. If the beam radius
  2176   Sun Apr 22 22:00:15 2018 awadeDailyProgressscatterSwitching out NF1811 detector for KA25MHzRather than beating the NF1811 dead horse
any more I've switched it out for the
new KA 26 MHz detector.  
  2403   Wed Aug 28 09:49:44 2019 anchalSummaryscatterBeam Dump StatusWe need to switch out normal flat-faced
beam dumps with triangular cavity beam dumps
in all places where they are not present.
  2528   Mon Feb 10 17:41:25 2020 anchalDailyProgressscatterCleaned up table; Installed hex beam dumpsToday I cleaned up the table, removed Scott's
RFAM measurement setup and installed hex
beam dumps on the input rejection of faraday
  2533   Thu Feb 13 18:00:30 2020 anchalDailyProgressscatterblocked NF1811 with hex beam dumpI have blocked the unused output port of
the beam splitter before our beatnote detector
with a hex beam dump at (13,
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