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ID Date Author Type Category Subject Text Attachments
  2911   Fri May 20 16:52:19 2022 ranaDailyProgressNoise Budgetmode matching, tfs, noiseI think in this plot, the actual phase
margin is ~45 deg, not 225 deg. It would
also be nice to indicate the gain margin
  Draft   Fri May 20 14:46:14 2022 JCUpdateVacuumSearching for Leaks on Statlin[Jordan, Shruti, JC]

Jordan and I headed over from 40
meter with the HLD. We
  2909   Thu May 19 14:28:29 2022 shrutiDailyProgressNoise Budgetmode matching, tfs, noiseThe present configuration: mode-matching
less than 50%,

south laser with LIGO custom current
  2907   Thu May 19 10:32:35 2022 ranaDailyProgressPSOMAnew PSOMA cavity configuration    
  2906   Thu May 19 10:16:04 2022 aaronDailyProgressNoise Budgetmode matchingI locked the cavity and added a 90-10 BS
after the MC2 cantilever mirror to send transmission
to both a DC PD and camera (90% reflection
  2905   Wed May 18 19:32:57 2022 aaronDailyProgressPSOMAnew PSOMA cavity configurationI used the LB servo's input offset
to null the current drive (with both inputs
disconnected). Also moved the PDH error signal
  2904   Wed May 18 13:39:00 2022 shrutiDailyProgressPSOMAnew PSOMA cavity configurationHere
are the calculations for the mode mismatch
between the horizontal (tangential) and vertical
  2903   Wed May 18 12:56:35 2022 aaronDailyProgressPSOMAnew PSOMA cavity configurationI added the South EOM into the fiber path
for the Teraxion laser. With the modulation
on, I now see the PDH error signal while
  2902   Wed May 18 11:19:34 2022 shrutiDailyProgressPSOMAnew PSOMA cavity configurationWith the current high power level (~40
mW) entering the cavity, I was able to align
so that I could visibly observe one round
  2901   Tue May 17 14:28:09 2022 aaronDailyProgressPSOMAnew PSOMA cavity configurationShruti tells us that our 1m curved mirror
operated at 45 degree incidence as MC1 will
introduce a 6-7% power mismatch due to astigmatism.
  2900   Fri May 13 15:02:29 2022 ranaDailyProgressPSOMAnew PSOMA cavity configurationAn added comment to Aaron's entry below:

Let us use the naming convention
which is commonly used in LIGO:
  2899   Fri May 13 12:57:30 2022 aaronLab InfrastructureVacuumleak checking cryo cantilevers vacuumJordan will soon bring over the leak checker
to debug our Statlin cryostat.

I powered up the vacuum gauge and
  2898   Thu May 12 11:22:44 2022 aaronDailyProgressPSOMAaligning[shruti, aaron]

We switched to the teraxion laser
today for a higher power to be able to align
  2897   Wed May 11 14:11:15 2022 aaronDailyProgressPSOMAaligningThanks, that description was very helpful
for understanding the state of the cavity
as soon as I walked in.
  2896   Wed May 11 12:42:04 2022 shrutiDailyProgressPSOMAaligningInitially I began with the procedure in
elog 2895, but realized that the height of
the beam was not parallel to the surface
  2895   Tue May 10 14:56:42 2022 aaronDailyProgressOpticsmeasured scatter for a while, but here's the cavity alignment procedureContinuing with alignment.

There are several spurious oscillations
(10s of Hz, few kHz, few MHz) on the REFL
  2894   Tue May 10 14:05:56 2022 shrutiDailyProgressOpticsReplaced the cavity input coupler with 99.994% R optic for higher finesse cavityI switched the optic so the HR surface
is inside the cavity. Still working on the
  2893   Thu May 5 17:09:06 2022 aaron DailyProgressPSOMAloop TFs and noise spectra[shruti, aaron]

For sanity purposes, we also plotted
the frequency noise spectrum as recorded
  2892   Thu May 5 17:01:40 2022 shrutiDailyProgressOpticsReplaced the cavity input coupler with 99.994% R optic for higher finesse cavity[shruti, aaron]

We replaced the 90-10 BS used as
the input coupler to the cavity with the
  2891   Thu May 5 14:09:42 2022 aaronDailyProgressPSOMAloop TFs and noise spectraI noticed that the oscilloscope was still
plugged in to a network switch, but the switch
itself was not plugged in to the router.
  2890   Wed May 4 15:52:56 2022 shruti DailyProgressPSOMAloop TFs and noise spectraAfter some troubleshooting I realized that
I was mistakenly measuring the PDH signal
coming from the not-in-use north laser PDH
  2889   Tue May 3 16:34:19 2022 ChrisDailyProgressPSOMAcurrent driver connections and cantilever acoustic dampingI opened the LIGO current driver chassis
for the north laser, to check its PCB revision.
It is v5 and will need modifications similar
  2888   Tue May 3 15:34:15 2022 aaronDailyProgressPSOMAloop TFs and noise spectraI updated the calibrated noise budget based
on Shruti's data above.

Shruti: Attachment 2 is
  2887   Tue May 3 09:51:42 2022 shrutiDailyProgressPSOMAloop TFs and noise spectraLoop
transfer functions

  2886   Fri Apr 29 11:21:51 2022 shrutiUpdatePSOMASwitch current driver to custom low noiseUsing the delay line setup with a digital
PID slow control on the Moku:Pro in multi-instrument
mode, I first calibrated the delay line by
  2885   Thu Apr 28 14:44:28 2022 aaronUpdatePSOMASwitch current driver to custom low noise[shruti, aaron]

PDH calibration

in the afternoon, we again measured the PDH
error signal sweep driving with 2V from the
  2884   Thu Apr 28 11:19:24 2022 shrutiUpdatePSOMASwitch current driver to custom low noise[chris, shruti, aaron]

 We turned down the current
on the Thorlabs ITC502, rack mounted the
  2883   Thu Apr 28 06:12:14 2022 ChrisElectronicsPSOMACurrent driver repair/upgradeOne of the D1200719
current driver boards (S1500270)
was in the EE shop for repair after some
  2882   Tue Apr 26 16:18:11 2022 aaronNoise HuntingNoise Budgetcalibrating PDH error signalI'm grabbing the pdh error signal from
the oscilloscope over ethernet (labutils/tektronix/tek-grabber.py),
and will calibrate the PDH error signal.
  2879   Tue Apr 26 14:28:51 2022 aaronThings to BuyOpticshigh reflectors in labWe have been wondering about the availability
of high reflecting optics for the PSOMA cavity,
especially the input / output coupler at
  2878   Mon Apr 25 13:54:03 2022 shrutiNoise HuntingNoise Budgetcalibrating PDH error signalAfter checking that the cavity locks, around
the same temperature and current set-point,
sweeping the current resulted in something
  2877   Thu Apr 21 18:13:36 2022 Ian MacMillanMiscEquipment LoanAccelerometer/seismometer loan Wilcoxon 731AReturned. See this

  2876   Wed Apr 20 15:48:07 2022 aaronNoise HuntingNoise Budgetcalibrating PDH error signalI'm calibrating PDH error signal first
to avoid recording data of 'dark noise'
with no PDH signal like yesterday
  2875   Wed Apr 20 14:27:41 2022 aaronLab InfrastructureGeneralstarting up after power outageI'm turning on the lab electronics
after the planned outage this morning.

Turned on following electronics.

  2874   Tue Apr 19 14:50:00 2022 aaronNoise HuntingNoise Budgetphotodiode dark noise measurementThings still look pretty weird. Today I'll
measure the photodiode dark noise (the previous
curve was theoretical, based on the known
  2873   Tue Apr 19 12:07:46 2022 shrutiLab InfrastructurePSOMAPSOMA table enclosure assembly[Aaron, Shruti]

We managed to install one of the
HEPA filter units on our enclosure today,
  2872   Fri Apr 15 16:25:00 2022 ranaNoise HuntingNoise Budgetlaser frequency noise measurementThe ITC 502 has an analog input modulation
impedance of 10 kOhm, according to the manual.
How did you set up the 16 dB attenuation?
  2871   Thu Apr 14 13:45:08 2022 aaronNoise HuntingNoise Budgetlaser frequency noise measurement[shruti, aaron]

We are measuring the frequency
noise on the beat note between the north
  2870   Wed Apr 13 11:10:28 2022 aaronNoise HuntingNoise BudgetPSOMA noise budgetNew measurements

Current noise

current noise following the procedures in
  2869   Tue Apr 12 15:00:39 2022 Ian MacMillanMiscEquipment LoanAccelerometer/seismometer loan Wilcoxon 731AI borrowed a Wilcoxon
Seismometer Model number 731A from the
cryo lab. I am also going to borrow
  2868   Tue Apr 12 12:16:58 2022 AaronDailyProgressSi fabBasic cantilever scribe and breakThis morning, I used the Dynatex scriber-breaker
at the KNI to make three silicon cantilevers
7cm x 1cm x 300um. These are similar dimensions
  2867   Mon Apr 11 16:30:12 2022 aaronNoise HuntingNoise BudgetPSOMA noise budgetWe'd like to progressively improve
the noise performance of the PSOMA cavity
by updating a noise budget when we make changes.
  2866   Wed Mar 30 16:18:58 2022 shrutiDailyProgressPSOMAMixing signal and pump (north and south)I fixed the fiber connections, re-organized
the fibers a little, and finally was able
to see a little less than 1.5 mW of power
  2865   Tue Mar 29 16:03:40 2022 shrutiDailyProgressPSOMAMixing signal and pump (north and south)[shruti, aaron]


Our next step
is to try and lock both lasers to the PSOMA
  2864   Thu Mar 10 13:43:20 2022 aaronMiscLasermode matching and slow servo, three corner hat revisitedI'd like to improve the mode matching.
Since it takes a while, I'll also set
up a slow servo on the TEC controller to
  2863   Wed Mar 9 14:20:26 2022 aaronDailyProgressElectronicsupdates to fiber patch cables, realignment, N laser in path, relock
Replaced the patch cable carrying
PSOMA South laser from the fiber box to the
table with 2x P3-1550PM-FC-10 cables (one
  2862   Tue Mar 8 13:45:20 2022 aaronDailyProgressElectronicssecond PDH box and EOMEntered the lab around 1:30pm to measure
the frequency noise of the PDH error signal
with the cavity locked. But I found some
  2861   Thu Mar 3 13:09:25 2022 aaronNoise HuntingLasersome noise budgets maybeI came to measure to measure the laser
frequency noise budget and see what I can
  2860   Tue Mar 1 17:08:47 2022 shrutiLab InfrastructurePSOMAPSOMA table enclosure assembly[Aaron, Shruti]

We installed all acrylic panels
on the enclosure today [Attachment 1]. Doing
  2859   Wed Feb 23 17:23:35 2022 ChrisElectronicsPSOMAcurrent driver statusThe current driver now in the EE shop for
troubleshooting (chassis S1500267/PCB S1500270)
looks to be a D1200719-v3
ELOG V3.1.3-