40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  SUS Lab eLog, Page 1 of 37  Not logged in ELOG logo
ID Date Author Type Category Subject Text Attachments
  1928   Tue Mar 8 09:32:56 2022 PacoDailyProgress1418 nm AUX ECDL1418nm ECDL Frequency noise[Paco, Radhika]

Beatnote recovery

Restarted
ECDL characterization last Friday. After
 schematic.pngraw_bn_spectrum.pngphase_timeseries.pngecdl_freqnoise.png 
  1927   Tue Oct 19 13:52:03 2021 RadhikaDailyProgress1418 nm AUX ECDL1418nm ECDL Frequency noise   ECDL_diagram.pdfECDL_FNM_13-10-2021_151524.pdf 
  1926   Mon Oct 4 17:44:34 2021 RadhikaDailyProgress1418 nm AUX ECDLFree space AOM[Paco, Radhika]

Last Friday we received a new lens
to direct the AOM 1st-order beam from
  
  1925   Wed Sep 22 16:44:34 2021 RadhikaDailyProgress1418 nm AUX ECDLFree space AOM[Paco, Radhika]

We had previously noticed that
the ECDL laser power seemed weaker compared
  
  1924   Thu Sep 16 15:21:21 2021 PacoDailyProgress1418 nm AUX ECDLFree space AOM[Paco,  Radhika]

Uninstalled the fiber AOM and temporarily
removed the third fiber 2x2 port beamsplitter.
  
  1923   Thu Sep 2 17:31:38 2021 RadhikaDailyProgress1418 nm AUX ECDL1418 nm ECDL Relative Intensity NoiseI took a relative intensity noise (RIN)
measurement of the ECDL, by feeding the 0th
order output of the AOM to the SR785. The
 ECDL_RIN_02-09-2021_165151_alone.pdf 
  1922   Wed Sep 1 13:12:02 2021 RadhikaDailyProgress1418 nm AUX ECDL1419 nm ECDL AOM diffraction at 95 MHz    
  1921   Tue Aug 17 11:09:29 2021 ranaDailyProgress1418 nm AUX ECDL1419 nm ECDL AOM diffraction at 95 MHzShould measure the S-matrix using a bi-directional
coupler.
  
  1920   Thu Aug 12 11:49:59 2021 RadhikaDailyProgress1418 nm AUX ECDL1419 nm ECDL AOM diffraction at 95 MHz[Paco, Radhika]

When previously trying to characterize
the AOM, we had noticed no 1st order diffraction
 zeroth_order_contour.pdffirst_order_contour.pdf 
  1919   Tue Aug 10 11:00:43 2021 PacoDailyProgressDOPODOPO v2[paco, nina]

We started rebuilding the DOPO
in the lab even though the new optical table
  
  1918   Tue Aug 10 09:51:44 2021 PacoDailyProgress1418 nm AUX ECDL1419 nm ECDL AOM diffraction at 95 MHz[radhika, paco]

We changed the setup to use a low
power amplifier rather than the 5W amp from
 rf_setup.jpg 
  1917   Wed Aug 4 11:36:30 2021 RadhikaDailyProgress1418 nm AUX ECDL1419 nm ECDL with 2um AOM tests[Radhika, Paco]

In order to transition the ECDL
laser noise characterization to a heterodyne
 rf_setup.jpgdiffraction_levels.png 
  1916   Wed Jul 14 12:21:08 2021 PacoDailyProgress1418 nm AUX ECDLECDL lases... and MZ locked mid-fringe[Paco]

Worked for a few hours to get the
aspheric properly aligned. The procedure
 selfhomodyne_1418.jpg 
  1915   Fri Jul 9 11:40:42 2021 PacoDailyProgress1418 nm AUX ECDLNew aspheric flexures[Radhika, Paco]

We tweaked the flexure alignment
until we had a nominally collimated beam
 IMG_1773.jpeg 
  1914   Wed Jul 7 13:05:07 2021 PacoDailyProgress1418 nm AUX ECDLNew aspheric flexures[Radhika, Paco]

Today we fired up the 1418 nm ECDL
and attempted initial adjustment of the aspheric
  
  1913   Thu Jun 10 09:59:52 2021 PacoLab InfrastructureDOPODisassembly for new optical tableToday the DOPO v0 got disassembled to make
way for the optical table swap. Most components
have been stored in the white cabinet's
 IMG_20210610_092713.jpg 
  1912   Wed Jun 2 18:37:09 2021 PacoSummaryCrackleVent crackle experiment[Paco, Anchal, Ian, Yehonathan]

Today, in preparation for the optical
table to come, we vented the big crackle
  
  1911   Thu May 20 17:09:43 2021 KojiSummaryGeneralAnother Heimann SensorAnother Heimann Sensor / Boston Electronics
delivered to Paco.
This unit (purchased May 2020/ / Delivered
 P_20210520_151126.jpg 
  1910   Wed May 19 09:25:34 2021 PacoNoise HuntingDOPO316 Hz noise[Paco]

- Have been investigating 316 Hz
noise in the control signal for the DOPO
  
  1909   Tue May 18 10:28:50 2021 PacoLab InfrastructureEquipmentLoanheimann sensor updateHeimann (HTPA80x64d) thermopile array;

-
First test to grab frames was done in my
personal Win10 machine, with no success.
 no_light.pnglight.png 
  1908   Wed Apr 14 16:49:30 2021 PacoMiscOptomechanicsDOPO mount v2Drew some new mounting scheme for the DOPO
cavity; main revisions with respect to the
current mount are -->
 dopo_mount_v2.pdf 
  1907   Tue Mar 30 15:18:06 2021 PacoLab InfrastructureEquipmentLoan2um CCD borrowedWith Aidan's assistance, I borrowed


WiDy SWIR camera (Pembroke
WiDy SWIR 640U-A) from the QIL (Attachment
 IMG_20210330_151046.jpgIMG_20210330_150958.jpg 
  1906   Tue Mar 9 19:21:38 2021 PacoMiscOpticsDOPO cavity pole- Noticed that the cavity transmission
peaks @ 1064 nm were much wider than originally
estimated by the dopo cavity design
  
  1905   Thu Feb 25 10:28:07 2021 PacoDailyProgressOpticsDOPO lock enduranceTest long term stability of the DOPO cavity
lock; The cavity remained resonant overnight
(start ~ 8 PM yesterday) and lost around
  
  1904   Wed Feb 24 17:42:49 2021 PacoDailyProgressGeneralDOPO locking and SHGLocking update

The plan during
these past few days has been to have fast
control loop of the cavity (locked to laser
 shg.jpg 
  1903   Thu Feb 18 09:39:01 2021 PacoDailyProgressElectronicsPDH error signal misbehavingError signal

Upon closer inspection
the error signal seems to vary quite significantly
on the scope (scanning @ 2 Hz), sometimes
 misbehaving_pdh.mp4 
  1902   Wed Feb 17 11:56:48 2021 PacoLab InfrastructureElectronicsUPDH box zero model and SR560 "lock"UPDHv3 box (serial 17142) is bogus. While
retrieving values of some of the components
to plug into working zero model, saw the
 updhv3_VGA_gain.pdfSR560_OLTFSR785_17-02-2021_164500.pdf 
  1901   Fri Feb 5 14:15:22 2021 ranaDailyProgressOpticsOPO cavity lockFor the splitting, I recommend not to use
a splitter.

Instead, you can use a -10 or -20
  
  1900   Thu Feb 4 16:46:06 2021 PacoDailyProgressOpticsOPO cavity lockDemodulation stage

Update on
demod. for OPO cavity lock. Last
related elog entry described prevalence
 rf_diagram.pngoffresonantpdherr.jpgpdherrorsig.png 
  1899   Tue Feb 2 17:39:52 2021 PacoDailyProgressOpticsre: Figuring out how much astigmatism is hurting usMotivated in part by the conclusions below,
improved estimated mode matching efficiency
from a poor 13% at the beginning of day to
  
  1898   Tue Feb 2 10:32:25 2021 AnchalSummaryOpticsFiguring out how much astigmatism is hurting usMethods


Use
the actual measured beam profile in X and
Y directions.
Propagate them with
 BeamProfilePropagation.pdf 
  1897   Tue Jan 26 11:47:12 2021 PacoDailyProgressGenerallow quality PDH error signalAfter getting what looked like a decent
cavity reflection signal, installed RFPD
yesterday. For this, removed the lens that
 poor_PDH_err.jpg 
  1896   Tue Jan 26 11:34:51 2021 ranaDailyProgressOpticsIncluded lens made by cavity input mirror and distrotion due to crystalwould be good if you could find a solution
that is not very sensitive to precise lens
placement
  
  1895   Tue Jan 26 11:33:32 2021 ranaDailyProgressOpticsIncluded lens made by cavity input mirror and distrotion due to crystal



  
  1894   Fri Jan 15 17:21:53 2021 PacoDailyProgressElectronicsRFPD TFRecord TF for RFPD SN09, resonant at 36
MHz, using the exact procedure as with EOM
Resonant Driver.
 RFPD009_TF_Inp_to_RFMon_Wide_15-01-2021_172008.pdf 
  1893   Fri Jan 15 10:57:39 2021 PacoLab InfrastructureEquipmentLoanBorrow AG4395A and EOM Driver TF re-tuneSee equipment borrowing note here.

Attempting TF measurement for resonant
EOM driver, but not having luck reproducing
 EOMDriver_TF_Inp_to_RFMon_CloseUp_15-01-2021_160402.pdfEOMDriver_TF_Inp_to_RFMon_Wide_15-01-2021_151039.pdf 
  1892   Wed Jan 13 17:52:35 2021 PacoDailyProgressOpticsOPO cavity resonanceObserved first resonant transmitted (&
reflected) light from the DOPO cavity; the
PZT scan was centered at 31 V, at 2 Hz, with
 dopo_first_resonance.jpgdopo_sideview.jpg 
  1891   Fri Jan 8 17:17:19 2021 AnchalDailyProgressOpticsIncluded lens made by cavity input mirror and distrotion due to crystalError in previous calculations:


We did not take into account
the effect of cavity input mirror on the
 Solutions.pdf 
  1890   Fri Jan 8 17:00:26 2021 AnchalDailyProgressOpticsIncluded lens made by cavity input mirror and distrotion due to crystal



 Solutions.pdf 
  1889   Thu Jan 7 17:09:16 2021 Paco & AnchalDailyProgressOpticsMode matching OPOFresh attempt at mode matching. For this,


Installed the oven, plugged
it to the controller and went to the nominal
  
  1888   Thu Jan 7 09:44:52 2021 PacoDailyProgressOpticsShaping the OPO cavity modeSummary of solution number 2 (from previous
post). 

After installing the lenses, mirrors
 profile_20210106.jpg 
  1887   Wed Jan 6 09:34:34 2021 AnchalDailyProgressOpticsCorrected analysis and found better solutions.Errors in the previous analysis


Previously,
we wrongly assumed. that the reflected light
from the cavity would be as if a reflection
 Solutions.pdf 
  1886   Thu Dec 31 16:41:59 2020 AnchalDailyProgressOpticsMode matching solution for CavityGoals and restrictions:


Use
the fewest lenses as possible.
The
beam widths in both onward and reflection
 Solutions.pdf 
  1885   Wed Dec 30 09:57:56 2020 PacoDailyProgressOpticsDOPO crystal ovenAssembled first DOPO oven with the crystal.
The components (shown below) are:


Oven clip
Oven
ITO
 ppktp2.jpgppktp1.jpg 
  1884   Mon Dec 28 15:51:51 2020 AnchalDailyProgressOpticsMode matching solution for CavityGoals and restrictions:


Use the fewest lenses as
possible.
The beam widths in both
 Solutions1-7merged.pdf 
  1883   Wed Dec 23 15:43:01 2020 PacoDailyProgress OPO cavity assemblyLaseroptik optics (4x pairs of cavity mirrors)
arrived earlier this week, so I began assembling
the input mirror with Noliac (NAC2124) PZT.
  
  1882   Tue Dec 22 15:54:03 2020 AnchalDailyProgressOpticsTook beam profile of near EOM area
After installing a 400mm focal
length plano-convex lens at 24" from
the laser head at (20, 12), we found that
 BeamProfileNearEOMAvg.pdf 
  1881   Mon Dec 21 16:35:14 2020 AnchalDailyProgressOpticsTook beam profile of laser right off the head
This is a repetition
of SUS/1864.
Used
 LaserHeadBeamProfileAvg.pdfLaserHeadBeamProfileX.pdfLaserHeadBeamProfileY.pdf 
  1880   Thu Dec 17 12:01:54 2020 PacoLab InfrastructureOpticscrystal ovens, clips and controllersCovesion order arrived, containing 2x


Crystal oven (20 mm long)
(below)
Clips (for mounting crystals)
 covesion_oven_clip_blank.jpg 
  1879   Thu Dec 17 11:59:14 2020 PacoMiscEquipmentLoanbeam profilerBorrow both beam profilers and laptops
from WB 264A.
  
ELOG V3.1.3-