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ID Dateup Author Type Category Subject Text Attachments
  2315   Thu Apr 4 18:40:18 2019 anchalDailyProgressMode matchingRe-aligned South PathPMC mode overlap was found
to be 68.77%. I realigned this to 91.99%.
Here, the percentage is the percentage of
  2316   Fri Apr 5 19:28:56 2019 anchalDailyProgressMode matchingRe-aligned South PathToday I aligned the south path completely
with about 60% matching with the cavity.
I guess I got lucky or I really know how
  2317   Mon Apr 8 19:19:02 2019 anchalDailyProgressFSSSouth FSS problemsThe ghost in South Cav Refl RFPD

doesn't boil if you watch it". I
routed +5V through unused pin 6 on the sub-D
  2318   Tue Apr 9 14:35:30 2019 anchalDailyProgressFSSSouth FSS problemsThis apparent problem is clear now. The
test path has a 100 ohm resistor to ground
(RF Board R10) which with rest of the resistances
  2319   Wed Apr 10 16:34:55 2019 anchalDailyProgressFSSSouth FSS problemsEOM Driver isn't driving hard

I suspected
that the EOM
  2320   Wed Apr 10 19:05:29 2019 UltramanDailyProgressFSSSouth FSS problemsALL
  2321   Fri Apr 12 11:43:33 2019 anchalNotesFSSPhotodiode C30642 doesn't has enough bandwidth![ED by KA, catalogs should not
be put on ELOG. This is public.]

Did we just miss this all along?
  2322   Fri Apr 12 11:55:54 2019 KojiNotesFSSPhotodiode C30642 doesn't has enough bandwidth!There is no problem. It is just a matter
of noise requirement.

How much shotnoise intercept current
  2323   Fri Apr 12 18:00:59 2019 KojiNotesFSSPhotodiode C30642 doesn't has enough bandwidth!Yeah, I realized I understood the mentioned
bandwidth wrongly. It is mentioned for a
direct 50 Ohm load while we load our photodiode
  2324   Sat Apr 13 16:23:30 2019 anchalDailyProgressFSSSouth Cavity Reflection Path resetToday I reset the reflection path from
faraday isolator to the RFPD.

First I slightly turned
  2325   Wed Apr 17 10:40:54 2019 KojiSummaryEquipment loanBorrowing an IPA/Acetone glass bottoles CTN->OMCI borrowed a small isopropanol glass bottle
from CTN to OMC (Apr 17, 2019)

I borrowed a small acetone glass
  2326   Wed Apr 24 16:01:55 2019 anchalDailyProgressFSSTime series and spectrum analysis of RFout of SCavReflRFPD near resonanceI took time series and spectrum of RF output
of South Cavity Reflection RFPD through a
20 dB coupler.
  2327   Thu Apr 25 20:24:27 2019 anchalSummaryElectronics EquipmentAdjustable TTL Trigger Generator BoxToday I made a standalone Adjustable TTL
Trigger generator box. Following are some
  2328   Fri Apr 26 14:34:03 2019 anchalDailyProgressFSSTime series and spectrum analysis of RFout of SCavReflRFPD near resonanceI think I figured the source of this 281
kHz peak. 281 kHz  ≈ 37 MHz
- 36.72 MHz, so it is the beat signal between
  2329   Sun Apr 28 22:29:18 2019 ranaSummaryElectronics Equipmentshould I use an OpAmp as a Comparator?not all amps are good for
use as a comparator
  2330   Sun Apr 28 22:31:39 2019 ranaDailyProgressFSSRF beatsbut if all systems are linear, where does
this beat physically get generated? What
are the actual modulation frequencies for
  2331   Tue Apr 30 18:07:49 2019 anchalDailyProgressFSSSpectrum of RFout from South Cavity Reflection RFPDToday, I finally used the trigger generator to
trigger near the start of the maximum of
PDH error signal to get an FFT when the PDH
  2332   Tue Apr 30 18:55:06 2019 anchalSummaryElectronics EquipmentFollow up on TTL Trigger generator boxBut I used AD620 which is an instrumentation
amplifier, not opamp. I thought comparators
are made with differential amplifiers (from
  2333   Wed May 1 18:45:47 2019 anchalNotesOtherTo scale complete optical layout of CTNI have completed making an optical layout
for CTN lab. From now onwards, I'll update
this layout if I make any major changes in
  2334   Thu May 2 14:38:41 2019 anchalDailyProgressSouth CavityCorrected input polarization into South CavityIn this week's group meeting, Andrew
mentioned that the polarization axes of the
AlGaAs mirrors are not properly aligned and
  2335   Thu May 2 15:55:18 2019 anchalDailyProgressSouth CavitySouth Cavity Alignment FixedI'm not sure how but the alignment
into south cavity became terrible over time.
Maybe I accidentally changes persicope alignment 
  2336   Mon May 6 20:12:22 2019 AnjaliSummaryEquipment loanBorrowed componentsI borrowed the following components from
PSL lab to QIL lab 

1. Mixer (Minicircuit, ZFM-3-S+)
  2337   Mon May 6 20:49:03 2019 anchalNotesPLLUsing PLL for Frequency Noise MeasurementI have finally completed the documentation
for mathematical analysis of using PLL for
frequency noise measurement. This document
  2338   Wed May 8 20:03:43 2019 anchalDailyProgressFSSFSS PDH Error Signal on South Path is in good healthEither by the mighty presence of Craig
who came down to lab for few minutes or because
of my recent updates in path alignment (see
  2339   Thu May 9 12:16:55 2019 anchalSummaryFSSSaving PDH error signal valuesI have made a SMA cable of length 1.952m
after optimizing phase delay of LO. This
is giving the maximum PDH error signal.
  2340   Fri May 10 15:50:09 2019 anchalSummaryComputersmodbus shifted to a git repo for version controlI today shifted our modbus (db files for
EPICS channels, ioc command files and docker-compose
file to run the services) over to this 
  2341   Mon May 13 16:25:14 2019 anchalSummaryComputersConverted all PSL_Lab links to CTN linksWe have changed the logbook name from PSL_Lab
to CTN. To keep all the links working, I
ran the attached script in a local copy of
  2342   Mon May 13 16:54:15 2019 awadeSummaryComputersConverted all PSL_Lab links to CTN linksAwesome. Can you do the same for crosslinks
to the old ATF_lab logbook name (ATF_Lab->
  2343   Mon May 13 19:12:56 2019 anchalDailyProgressOtherSet experiment for 2.6 mW transmission from cavities.I tuned the intensity control and changed
autolock parameters to get 2.6 mW light at
the output of cavities on both paths. At
  2345   Tue May 14 18:13:21 2019 anchalDailyProgressComputersAdded threshold channels in autolocker and fastmon rms monitorI was finding myself changing thresholds
every time I change power levels. Also, the
fastmon rms monitors were not working
  2346   Wed May 15 19:00:26 2019 anchalDailyProgressSouth CavityChanges on South Path towards increasing power on FSS RFPD For gaining about 3.45 mW of light after
reflection from cavity on resonance when
mode matching is about 60%, 8.63 mW light
  2347   Thu May 16 13:46:46 2019 anchalDailyProgressTempCtrlAlignment disturbing due to lab temp changesAs suspected in CTN: 2346, the
mode matching of the cavities is deteriorating
and eventually alignment is getting screwed
  2348   Thu May 16 16:34:30 2019 anchalDailyProgressNorth CavityChanges on North Path towards increasing power on FSS RFPD Similar to South Path, I have inserted
a beam splitter in the north PMC reflection
path. This is a BS1-1064-90-1037-45UNP beamsplitter
  2349   Wed May 22 17:48:49 2019 anchalDailyProgressTempCtrlVacuum Can Temp Sensors restarted with new boardI installed the new board LIGO-D1800304 with
an external voltage regulator and breakout
box for handling acromag channels. See attached
  2350   Thu May 23 15:45:48 2019 anchalDailyProgressFSSOscillations in North FSS Mixer Channel and powerAfter the vacuum can is heated, I aligned
the north cavity again today to about 60%
mode matching. however, I'm seeing a
  2351   Thu May 23 15:56:22 2019 awadeDailyProgressFSSOscillations in North FSS Mixer Channel and power~7kHz would be close to the cross over
frequency wouldn't it? Maybe also see
if you can capture PZT and EOM actuation
  2352   Wed May 29 18:50:18 2019 anchalDailyProgressFSSNorth FSS F and Crossover Frequency MeasurementI took the transfer function of North FSS
side to see how much suppression we are doing.
I took the transfer function by sending source
  2353   Mon Jun 3 17:44:30 2019 anchalDailyProgressNoiseBudgetNew Beat Note measurementToday I took a beat note noise measurement
to see where we are. Attached is the updated
noise budget.
  2354   Tue Jun 4 20:44:21 2019 ranaSummaryOthernext steps
Fix the temperature control so
that the fluctuation over hours time scale
is low as Tara/Evan had it. This will allow
  2355   Thu Jun 6 18:14:17 2019 anchalDailyProgressBEATMoku Lab Frequency Noise AnalysisI spent some time understanding moku and
even though it has some flaws (like no scriptable
channel for recording data), it seems like
  2356   Fri Jun 7 17:42:06 2019 anchalDailyProgressBEATThree Corner Hat Method   6x 
  2357   Mon Jun 17 18:05:20 2019 anchalDailyProgressBEATMoku Frequency Noise MeasurementI thought, why not just measure Moku's
own synthesized frequency output with itself.
Attached plot shows the frequency noise measured
  2358   Mon Jun 24 14:00:40 2019 ScottADailyProgressEOMBias Tee AdditionEOM Bias Tee:

will make use of the RF Monitoring Circuit
present on the driver for high impedance
  2359   Thu Jun 27 17:06:57 2019 ScottADailyProgressRFAMBias Tee S MatrixIn order to
better characterize the Bias Tee, I measured
the non-diagonal components of it's S
  2360   Tue Jul 2 17:22:16 2019 ScottADailyProgressRFAMBias Tee Data AnalysisProcedure

First I calculated
the transfer function for the ideal condition of
  2361   Wed Jul 3 11:33:47 2019 ScottADailyProgressRFAMTuning Inductor value for EOM Driver LTspice

the values for the bias tee found before,
  2362   Thu Jul 4 16:46:01 2019 ScottADailyProgressRFAMReflow SolderingI have soldered one full EOM driver
with the tunable inductor mentioned
before, as well as another driver without
  2363   Wed Jul 10 12:37:38 2019 ScottADailyProgressTempCtrlAD590 BoardI reflow soldered 3 channels to an AD590
temperature board for a differential measurement test.
I expect to run the experiment soon to see
  2364   Wed Jul 10 12:46:07 2019 ScottADailyProgressRFAMAddition of 1k ohm Resistor to input of DC port on Bias TeeMy goal was to investigate the effect of
placing a 1k ohm resistor as the input of
the DC port of the Bias Tee. The expectation
  2365   Wed Jul 10 18:01:24 2019 ranaDailyProgressTempCtrlAD590 Boardshow us what you got for the LISO or ZERO
noise budget of this circuit before testing;
also sketch of the experiment setup
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