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ID Dateup Author Type Category Subject Text Attachments
  51   Fri Feb 5 20:37:06 2010 Tara ChalermsongsakLaserRefCavbetter pointing alignment After adjusting the mirror for reflecting
beam back to the AOM, the QPD signal shows
the better alignment. Before the voltage
  52   Fri Feb 5 20:53:58 2010 FrankLaserRefCavlatest values for refcavvalues for  VCO pwr 4.7V
RCTRANSPD signal: 5.17V
DC-level of RF-PD:
  53   Fri Feb 5 21:10:48 2010 FrankLaserRefCavnew PD for frequency-shifted power detectionadded a detector behind the curved mirror
to measure the changes in deflected power
(1.order) while changing the frequency of
  54   Fri Feb 5 21:53:13 2010 FrankLaserRefCavstrange things going onin order to get an idea about the part/subsystem
causing the RF power modulation while sweeping
the VCO frequency i changed the length of
  55   Sat Feb 6 12:19:14 2010 ranaLaserRefCavstrange things going on Seem like
a screwy AOM. I would take the double-passed
  56   Sun Feb 7 18:29:06 2010 FrankLaserLasernew channels + changesadded the following channels:
C3:PSL-RCAV_DIFFPWR : diffracted
power (single pass) measured behind curved
  57   Sun Feb 7 20:56:03 2010 FrankLaserRefCavAOM power modulation & pointingseems like a bad AOM and an impedance matching
problem together. exchanging the semi-rigid
cable by other cables produces a lot of different
  58   Mon Feb 8 18:08:53 2010 FrankMiscAOMthermal images of AOMtook some images with the thermal imaging
camera of the AOM installed in the PSL so
far. The first three pictures show the AOM
  59   Mon Feb 8 18:12:46 2010 FrankNotesAOMimpedance measurementsmeasured the impedance from 70MHz to 90MHz
for three different AOMs we had in the lab
- two Isomet 1205C-843 and one Crystal Technologies
  60   Mon Feb 8 18:27:42 2010 Tara ChalermsongsakLaserRefCavChaging Isomet AOM to Crystal Tech AOM

  61   Mon Feb 8 22:03:32 2010 FrankLaserRC noisenew resultseverything is back, pointing is much much
less, power modulation too, ugf of the other
loop is much higher - but nevertheless the
  62   Tue Feb 9 18:33:59 2010 FrankLaserRC noiseeven newer resultsmeasured a couple of times today with everything
re-aligned and different gain settings for
the FSS stuff. Measured also to lower frequencies.
  63   Wed Feb 10 04:01:50 2010 ranaLaserRC noiseeven newer resultsLooking better. I'm curious about what
the existing loop shapes are. The old FSS
hardware is designed to drive an NPRO + 1
  64   Wed Feb 10 18:04:01 2010 Tara ChalermsongsakLaserRefCavQPD calibrationToday I calibrated the QPD on the ref cavity.
The armlength from AOM to the quad is 2.1
  65   Fri Feb 12 12:46:38 2010 Tara ChalermsongsakLaserLasera picture of beam path on the optic benchI took a picture of the setup in
PSL lab, and drew a line for laser path.
I omit the mode cleaning part since it's
  66   Tue Feb 16 19:33:53 2010 FrankLaserLaserseveral shutdowns the last dayswe had several shutdowns of the laser within
the last days. A couple of times the well
known "HT error", today we had
  67   Wed Feb 17 15:40:04 2010 FrankLaserLaserold 100mW NPROdoes anyone know the typical operating
current for the 100mW lightwave laser model
? (M126N-1064-100) It's typically ~1.1A for
  68   Thu Feb 18 15:07:39 2010 FrankMiscLaserboth IR viewers missingso please bring it back - we are waiting
for it and can't go on without those... For
the future: if you take it, bring it back
  69   Fri Feb 19 00:31:40 2010 FrankLaserLaser100mW lightwave NPRO slopePeter gave me the hint that the default
values are stored in an eeprom in the laser
head. So connecting the head to a driver
  70   Fri Feb 19 18:23:24 2010 Tara ChalermsongsakLaserRefCavalignment for measuring beat between 2 cavitiesI finished aligning the beams from Ref
cavity and Acavity, broke a connector on
the PD we were going to used to measure the
  71   Mon Feb 22 11:25:51 2010 FrankLaserLaserlaser fault againthe laser stopped working while beeing
in the lab but not touching the laser or
table or anything. I was looking for an EOM
  72   Mon Feb 22 16:21:43 2010 Frank, TaraLaserRC noiseboth cavities locked, optimizing beat signaltuned the temperatures over night to be
able to lock both cavities today. Cavities
are now locked and Tara is optimizing the
  73   Mon Feb 22 18:58:23 2010 Tara ChalermsongsakLaserRefCavbeat frequency between transmitted beams Today  we finally see the beat
between transmited beams from Ref Cavity
and A Cavity.  Now we are trying to
  74   Tue Feb 23 20:13:00 2010 Tara ChalermsongsakLaserRefCavsuccessfully use ifr2023 to track the frequncy drift of the beat  The drift in the demodulated signal
(beat frequency x local oscillator) can be
tracked by using ifr2023 and sr560. We successfully
  75   Wed Feb 24 11:58:20 2010 ranaLaserRefCavsuccessfully use ifr2023 to track the frequncy drift of the beatVolts? What are Volts???
This plot should be converted into
radians/rHz or Hz/rHz in order to be used.
  76   Wed Feb 24 19:40:25 2010 Tara ChalermsongsakLaserRC noisecalibrating ifr2023The calibration for ifr203 input for external
frequency modulation is 
  77   Wed Feb 24 20:07:00 2010 Tara ChalermsongsakLaserRC noiseRC frequency noise I changed the gain setting on SR560
to find how it will effect the noise floor
of the RC noise.
  78   Thu Feb 25 19:03:59 2010 Tara ChalermsongsakLaserRC noiseNoise floor from PD and SR560Noise floor from PD and SR560 are measured,
then converted from V/rHz to frequncy/rHz
by the calibration from IFR2023 (0.7 MHz/Volt).
  79   Fri Feb 26 11:40:47 2010 FrankComputingDAQacav VME crate stopped workinglast night one of the DAQ cards failed
and the acav crate stopped working, so also
the temp stabilization of the analyzer cavity
  80   Fri Feb 26 15:15:56 2010 Tara ChalermsongsakLaserRC noisequarter wave plate added/power from Ref and A Cavs measuredI borrowed one of the quarter wave plate
and added it after the beam from the Ref
Cav. One more QWP is needed for the ACav.
  81   Sun Feb 28 23:53:21 2010 ranaLaserRC noiseNoise Budget   rcnb.png 
  82   Mon Mar 1 17:52:46 2010 Tara ChalermsongsakLaserRC noiseNew ResultI got a quarter wave plate from Greg Ogin
this afternoon. The attached plots show:
black-> RC noise when there are
  83   Mon Mar 1 22:39:39 2010 ranaLaserRC noiseNoise Budget40m entry on RIN induced thermo-optic noise
  84   Wed Mar 3 08:46:26 2010 ranaLaserRC noiseNoise as measured by the 40m MCThis
link points to a measurement of the frequency
noise at the 40m.
  85   Wed Mar 3 15:59:10 2010 Tara ChalermsongsakLaserRC noiseNoise from function generator I took the data of frequency noise
of the functiongenerator("Marconi")
and spectrum analyzer's noise from Mott's
  86   Thu Mar 4 19:44:08 2010 Tara ChalermsongsakLaserRC noiseNoise from VCOVCO frequency noise is measured. V input
is 4.7 Volt. The signal output from the VCO
(which controls the AOM) is mixed with signal
  87   Fri Mar 5 00:34:09 2010 FrankLaserRC noiseNoise from VCO

  88   Fri Mar 5 14:40:21 2010 FrankLaserRC noiseNoise from VCO

  89   Thu Mar 11 22:45:58 2010 Tara ChalermsongsakLaserRC noiseVCO f noiseI measured the VCO noise again.  2
methods that I tried
1) Measuring noise from a) suppressed
  90   Tue Mar 23 00:26:43 2010 Frank, TaraMiscRefCavongoing workover the weekend we baked the two AR-coated
windows for the new chamber.  Bob doesn't
need the oven the next couple of days so
  91   Tue Mar 23 21:17:56 2010 Frank, TaraMiscRefCavfoam cut & partly assembledwe've cut the rest of the foam parts to
fit on the smaller diameter (the main tube
with the heaters). We already started to
  92   Thu Mar 25 13:05:59 2010 FrankMiscRefCavall parts bakedby now all parts are baked and ready for
assembly. The only part we couldn't bake
is the chamber itself. But Bob said that
  93   Mon Mar 29 17:46:41 2010 Frank, TaraMiscRefCavassembled new vacuum chamberwe cleaned
and assembled the new vaccum chamber. we
installed an electical feedtrough (for sensors
  94   Wed Mar 31 20:46:22 2010 FrankMiscRefCavion pumpsi've made a cable to test the two Varian
ion pumps we have.  Before we move the
cavity to the new chamber i would like to
  95   Thu Apr 1 15:38:38 2010 FrankMiscDAQRT DAQ equipment arrivedthis afternoon the PSL RT DAQ equipment
arrived and we moved all the stuff down to
the PSL lab. We now have to expansion chassis,
  96   Fri Apr 2 00:35:00 2010 FrankMiscRefCavnew chamber almost readythe new chamber is almost ready. I've attached
three of four heaters, the fourth one has
a fabrication error and has to be replaced.
  97   Tue Apr 6 18:39:04 2010 Tara ChalermsongsakLaserRefCavCalculation for higher order mode's frequency I calculated the frequency for other
higher Hermite-Gaussian modes, (n+m up to
20) to make sure that there is no overlap
  98   Wed Apr 7 12:30:47 2010 ranaLaserRefCavCalculation for higher order mode's frequencyI deleted your plot, since it contained
no axes labels. We have a strict rule
against plots like those. You must have physical
  99   Wed Apr 7 18:29:16 2010 Tara ChalermsongsakLaserRefCavCalculation for higher order mode's frequencyThere's a correction
1) the beam waist inside the cavity,
it seems that the 237 um(which corresponds
  100   Fri Apr 9 21:34:15 2010 FrankComputingDAQnew RT systemi assembled everything and made all the
cables for power distribution etc. I also
got (the last) timing slave from Rolf.
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