40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log, Page 322 of 346  Not logged in ELOG logo
ID Date Author Type Categorydown Subject Text Attachments
  17274   Wed Nov 16 18:41:17 2022 yutaSummaryBHDOptical gain calibrations for BHD MICHOptical gains of AS55 and BH55 are calibrated
for BHD MICH.

LO-ITM single bounce:
 Screenshot_2022-11-16_18-57-12.pngScreenshot_2022-11-16_18-49-53_BHDMICHCalLines.pngLSC-AS55_Q_ERR_DQ_1352689642.png 
  17279   Thu Nov 17 14:12:58 2022 yutaSummaryBHDOptical gain calibrations for BHD MICH with lower UGF[Paco, Yuta]

We found that MICH UGF was unexpectedly
 Screenshot_2022-11-17_14-39-17_MICHLOPHASEOLTF.pngScreenshot_2022-11-17_14-41-40_LowUGFConfiguration.png 
  17282   Thu Nov 17 20:02:10 2022 yutaSummaryBHDMICH optical gain measurements with different LO phasesMICH
optical gain was measured with different
LO phases over ~90 degrees.
 UncalibratedMICHOpticalGainVSLOphase20221117.pngCalibratedMICHOpticalGainVSLOphase20221117.png 
  17284   Fri Nov 18 13:05:00 2022 yutaSummaryBHDGains adjusted for bandstop filters for BHD optics[Paco, Yuta]

We realized that bandstop filters
 Screenshot_2022-11-18_13-16-31_AS1ViolinFilters.png 
  17285   Fri Nov 18 16:58:39 2022 yutaSummaryBHDActuator calibrations for MICH BHDAs there is some confusion in actuator
calibration, we have done the measurement
again from scratch.
 7x 
  17287   Fri Nov 18 22:46:02 2022 yutaSummaryBHDMICH optical gain measurements with different LO phases, with signsMICH
optical gain with a sign was measured with
different LO phases over ~180 degrees, with
 UncalibratedMICHOpticalGainVSLOphase20221118.pngCalibratedMICHOpticalGainVSLOphase20221118.png 
  17294   Mon Nov 21 17:44:00 2022 yutaSummaryBHDMICH BHD displacement sensitivity with AS55_Q and BHD_DIFF[Paco, Yuta]

MICH displacement sensitivity was
compared under AS55_Q locking and BHD_DIFF
 Screenshot_2022-11-21_17-33-20_OLTF.pngScreenshot_2022-11-21_17-45-25_MICHBHDDisplacement.png 
  17296   Mon Nov 21 18:43:46 2022 yutaUpdateBHDc1hpc and c1lsc modified to send BHD_DIFF and BHD_SUM[Anchal, Yuta]

To send BHD signals from c1hpc after
 Screenshot_2022-11-21_18-42-49_BHD.png 
  17301   Wed Nov 23 11:06:08 2022 AnchalUpdateBHDc1hpc and c1sus modified to add BS dither and demodulation optionc1hpc has option of dithering BS now (sending
excitation to BS LSC port to c1sus over IPC).
This is available for demodulating BHDC and
  
  17302   Wed Nov 23 12:58:33 2022 YehonathanUpdateBHDSome more calculationsChanged the BHD BS transmissivity to 0.56.

Demodulation Phases

As was noted before. The LO phase
 LO_phase_sens_vs_LO_phase_RF.pdfLO_phase_sens_vs_LO_phase_RF_fixed_demod.pdfLO_phase_sens_vs_MICH_Offset.pdf 
  17303   Wed Nov 23 14:59:11 2022 PacoSummaryBHDBHD_DIFF sensitivity to BS dither with MICH Offset[Yuta, Paco, Anchal]

We measured

(a)
 BHDIFF_rand_SensvsMICHOffset.pdf 
  17308   Wed Nov 23 17:28:39 2022 YehonathanUpdateBHDSome more calculationsFields at the BHD BS. More on this later.  Fields_at_BHDBS.pdf 
  17309   Wed Nov 23 20:58:23 2022 yutaSummaryBHDBHD_DIFF sensitivity to BS dither with MICH Offset with different BH55 demodulation phases[Anchal, Paco, Yuta]

Attachment #1 is the same plot as 
 BHDIFF_rand_SensvsMICHOffset_pydemod.pdfBHDIFF_rand_SensvsMICHOffset_pydemod_NoMICHinBH55Q.pdfBHDIFF_rand_SensvsMICHOffset_pydemod_BH55at70deg.pdfMICHBHD_BH55.pdf 
  17317   Mon Nov 28 16:53:22 2022 AnchalSummaryBHDF2A filters on LO1 LO2 AS1 and AS4[Paco, Anchal]

I changed the script in /opt/rtcds/caltech/c1/Git/40m/scripts/SUS/outMatFilters/createF2Afilters.py
  
  17319   Mon Nov 28 18:21:50 2022 PacoSummaryBHDBH44 prepI checked the LSC rack to evaluate what
we might need to generate 44 MHz rf in the
hypothetical case we go from BH55 to BH44
  
  17322   Tue Nov 29 15:32:32 2022 AnchalUpdateBHDc1hpc model updates to support double audio ditherMany changes have been done to c1hpc to
support dual demodulation at audio frequencies.
We moved away with ASS style of lockin setup
 Screenshot_2022-11-29_15-36-05.png 
  17339   Tue Dec 6 13:09:44 2022 yutaUpdateBHDc1cal model updates to support sensing matrix for BHD[Anchal, Yuta]

We have modified c1cal model to support
 Screenshot_2022-12-06_13-02-05_c1calMEDM.pngScreenshot_2022-12-06_13-06-35_c1lsc.pngScreenshot_2022-12-06_13-07-14_c1cal.pngScreenshot_2022-12-06_13-07-50_c1caldemod.png 
  17343   Tue Dec 6 17:12:23 2022 yehonathanSummaryBHDLO phase control using audio (MICH and AS1) + RF{Yuta, Yehonathan}

Today we lock LO phase using audio+RF
method in two variants: AS1+RF and MICH(BS)+RF.
 Screenshot_2022-12-06_16-44-37_LOPHASE_OLTF_BH55_Q_AS1dither.pngScreenshot_2022-12-06_17-10-47_LOPHASE_OLTF_BH55_Q_BSdither.png 
  17345   Wed Dec 7 16:21:05 2022 yutaSummaryBHDImproved MICH BHD alignment[Yehonathan, Yuta]

We found that moving AS1 in yaw improves
 LSC-AS55_Q_ERR_DQ_1354479181.png 
  17347   Thu Dec 8 17:52:39 2022 yutaSummaryBHDMICH BHD optical gain measurements at different LO phases, RF+audio dither[Yehonathan, Yuta]

Sensing matrix measurements at
different LO phases were performed under
 BHDMICHSensingMatixvsLOPhase1354581028.pdfBHDMICHSensingMatixvsLOPhase1354580582.pdfBHDMICHSensingMatixvsLOPhaseCombined.pdf 
  17351   Fri Dec 9 13:18:57 2022 yutaSummaryBHDMICH BHD optical gain measurements at different LO phases, elliptic fit[Yehonathan, Yuta]

Here's a plot using same dataset
 BHDMICHSensingMatixvsLOPhaseCombinedXYPlot.pdf 
  17398   Fri Jan 13 13:34:12 2023 AnchalSummaryBHDBH44 tuned and transimpedance measuredI've tuned one gold box RFPD to be
resonant at 44.26 MHz and I left the notch
to be near 66 MHz, however, it is only effective
 BH44_Transimpedance_From_Test_Port.pdf 
  17401   Tue Jan 17 20:03:19 2023 yutaSummaryBHDBH44 installations: IQ demodulator is not orthogonal[Anchal, Paco, JC, Yuta]

We have started hardware installations
 6x 
  17402   Wed Jan 18 20:57:53 2023 PacoSummaryBHDIQ demod orthogonalI tested a spare IQ demod board labeled
33.3 MHz (closer to 44 MHz than the 165 MHz
we had started using) and using the Moku
  
  17403   Thu Jan 19 12:12:09 2023 AnchalSummaryBHDIQ demod orthogonalBy sending two frequencies offset from
eachother to LO input and RF input, we measured
the remaining phase difference between I
 BH44_IQDemodMeasuredDiff_1358192471.pdf 
  17404   Thu Jan 19 14:58:40 2023 ranaSummaryBHDIQ demod orthogonalthe
problems with these circle plots:
  
  17405   Thu Jan 19 18:15:48 2023 yutaSummaryBHDBH44 RFPD optical path and LO/AS camera[JC, Paco, Anchal, Yuta]

- We installed the new BH44 beam path
 PXL_20230120_000603659.jpgScreenshot_2023-01-19_18-42-03_LO-ITMX_BH44Lock.pngScreenshot_2023-01-19_18-29-24_60Hzandfriends_FPMIBHD.png 
  17410   Mon Jan 23 11:20:44 2023 JCSummaryBHDBH44 RFPD optical path and LO/AS cameraHere's the beam path of BH44.  BH44.jpg 
  17413   Mon Jan 23 22:51:17 2023 yutaSummaryBHD60 Hz harmonics side lobe investigations[Paco, Yehonathan, Yuta]

Since we have installed BH44, we
are seeing side lobes of 60 Hz + harmonics
 Screenshot_2023-01-24_11-43-40_POXPOYDark.png 
  17414   Tue Jan 24 11:21:59 2023 yutaSummaryBHDFPMI displacement noise with 60 Hz harmonics side lobesJust to show how bad 60 Hz noise is, I
compared FPMI displacement noise with pre-BH44
era (measured on Jan 13, 40m/17400).
 FPMI_calibrated_noise_20230124_60Hz.pdfScreenshot_2023-01-24_11-27-22_FPMIndscope.png 
  17415   Tue Jan 24 16:12:07 2023 ranaSummaryBHDFPMI displacement noise with 60 Hz harmonics side lobes1) do a comparison with the whtiening before
the ADC on/off. This will tell us if it is
pickup before the whtiening filter or not.
  
  17417   Tue Jan 24 21:29:31 2023 yutaSummaryBHDElectronics diagram around BH44 and BH551) Turning the whitening filter before
the ADC on/off didn't changed the relative
height of 60 Hz peak compared with the
 BH44BH55Diagram.pdf 
  17419   Wed Jan 25 11:35:20 2023 yutaSummaryBHDREFL55 visually inspected, BH44 Kapton tapedFollowing was done to investigate 60 Hz
noise issue, but no significant change in
the FPMI noise observed.
 REFL55.JPGBH44Kapton.JPG20230125_FPMIBHDPDs_Spectra_FPMILockedBH55Locked.pdf20230125_FPMIBHDPDs_Spectra_FPMILockedBH55LockedNoWhitening.pdf20230125_FPMIBHDPDs_Spectra_FPMILockedBH55LockedResG60InCARM.pdf 
  17421   Wed Jan 25 14:33:07 2023 ranaSummaryBHDREFL55 visually inspected, BH44 Kapton tapedKapton tape is a good insulator, so its
a good block for 60 Hz. But it is mostly
useless for RF since the capacitance between
  
  17423   Wed Jan 25 18:01:21 2023 yutaSummaryBHDBH44 setup isolated, but 60 Hz noise stays the same[Paco, Anchal, Yuta]

Isolating
BH44 setup from the rest didn't help
 BH44BH55Diagram_Disconnected.pdf20230125_FPMIBHDPDs_Spectra_BothArmsLocked.pdf20230125_FPMIBHDPDs_Spectra_BothArmsLockedBH44Removed.pdf20230125_MCF.pdf 
  17431   Fri Jan 27 19:35:31 2023 yutaSummaryBHD60 Hz noise investigations around IMCSo far different measurements are consistent
with the hypothesis that the 60 Hz noise
is from PSL frequency noise (40m/17423).
 6x 
  17432   Fri Jan 27 21:22:57 2023 yutaSummaryBHDV beam dump installed for BH44 RF PDOne of these V beam dumps was installed
for BH44 RF PD.
The rest is now stored in the box
 V.JPG 
  559   Tue Jun 24 22:31:10 2008 MashaUpdateAuxiliary lockingmy first step in fiber stabilizationThere is a new 1W INNOLIGHT NPRO laser at
the Symmetric Port.
  
  564   Wed Jun 25 11:01:45 2008 MashaUpdateAuxiliary lockingfiber stabilizationFor the first week, I have been learning about
fiber noise cancellation, auxiliary locking
techniques, and other relevant helpful topics
  
  620   Wed Jul 2 00:59:13 2008 MashaUpdateAuxiliary lockingbalanced detection, noise plots, progressProgress report submitted today(!). It is
on the 40m wiki page. Below is a figure of
some estimated noise sources.
 noise_sources.pdfbalancing_detectors.png 
  647   Tue Jul 8 10:26:30 2008 MashaUpdateAuxiliary lockingsetup updatesYesterday I changed one of the beam splitters
in the Mach Zehnder to one with a more stable
mount as to reduce the system's coupling
  
  679   Wed Jul 16 11:00:15 2008 MashaUpdateAuxiliary lockingimproving ADC input for the mach zehnder setup and completely unrelated happeningsFor most of last week, the SURFs + Jenne were
helping Mike and Ken with "stray light control
for
  
  685   Wed Jul 16 17:51:58 2008 MashaUpdateAuxiliary lockinglong measurementI'm taking a measurement on the SR785 spectrum
analyzer at low frequencies, so I'm going
to leave it by the symmetric port table for
  
  686   Wed Jul 16 22:29:05 2008 MashaUpdateAuxiliary lockinglong measurement[quote]I'm taking a measurement on the SR785
spectrum analyzer at low frequencies, so
I'm going to leave it by the symmetric port
  
  698   Fri Jul 18 19:30:20 2008 MashaUpdateAuxiliary lockingmoving from 40mI will be working in the basement of Bridge
probably starting next week; I moved the
NPRO laser and some of the optics from my
  
  734   Thu Jul 24 11:49:07 2008 MashaSummaryAuxiliary lockingbelated weekly summaryI designed a high pass filter to whiten the
spectrum from the Mach Zehnder to optimize
the 
 filter_tr_function.pdffiltered_spectr0724.pdf 
  764   Wed Jul 30 12:03:44 2008 MashaSummaryAuxiliary lockingweekly summaryI've been learning about mode matching/beam
propagation, so I can work on getting more
 mz_fiber_noise0730.pngsetup0730.JPGMZnoise_sources0727.png 
  804   Wed Aug 6 13:57:44 2008 MashaSummaryAuxiliary lockingweekly summaryFinished second progress report.

Working on improving the sensitivity of the
  
  1205   Mon Dec 29 18:01:07 2008 AidanUpdateAuxiliary lockingUpdated 40m Upgrade Document T080074-00-R
Added a paragraph to the 40m Upgrade document
describing the fiber stabilization and frequency
  
  1490   Thu Apr 16 16:37:42 2009 AlbertoUpdateAuxiliary lockingthe zipper It takes 18 months to double the computational
power of microprocessors but it took man
thousands of years to invent the zipper.
 19_3f_Current_40m_plots_SUCCESS.pdf 
ELOG V3.1.3-