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ID Date Author Type Categoryup Subject Text Attachments
  2386   Sun Aug 11 01:22:04 2019 Shalika SinghNoise Budget2micronLasersNoise Analysis of voltage regulator using SR785 Spectrum AnalyserA comparison between the types of voltage
regulators was done in order to know which
should be preferred to provide a clean
 regulator.pdfNoise_across_Voltage_Regulator_Circuit.pdf 
  2387   Sun Aug 11 14:35:41 2019 KojiNoise Budget2micronLasersNoise Analysis of voltage regulator using SR785 Spectrum AnalyserQuestions:

1) Has the DC output voltages of
the regulators checked?
  
  2388   Sun Aug 11 19:15:32 2019 Shalika SinghNoise Budget2micronLasersNoise Analysis of voltage regulator using SR785 Spectrum AnalyserAnswers:

1. For LM317 I received the output
of 11.2V and for LM7915 -10V and for LM7815
  
  2389   Sun Aug 11 22:34:50 2019 KojiNoise Budget2micronLasersNoise Analysis of voltage regulator using SR785 Spectrum Analyser3. You need to flip the direction of the
diode.

1&2 OK, so the circuits were
  
  2390   Mon Aug 12 11:37:36 2019 Shalika SinghNoise Budget2micronLasersNoise Analysis of Circuit using SR785 Spectrum Analyser and Zero SimulationReferring to elog entry 2385. I did the
measurements again because mistakingly I
had been using the SR560 with it's AC
 7x 
  2391   Mon Aug 12 11:51:38 2019 Shalika SinghNoise Budget2micronLasersNoise Analysis of Voltage Regulator using SR785 Spectrum AnalyserReferring to elog entry QIL:2387. I did
the correction with the voltage supply and
now provided a supply of 18V(+/-) to LM7815
 regulator.pdfNoise_across_Voltage_Regulator_Circuit.pdf 
  2392   Mon Aug 12 12:09:00 2019 Nathan HollandSummary2micronLasersAdjusting the Voltage/Frequency Offset on the Brimrose AOM Driver.The 80 MHz brimrose AOM driver, which came
with the AOM, can actually drive between
75 MHz and 85 MHz. It has an input port,
 2um_MachZehnder_wide_PowerSpectrum_Screenshot.png2um_MachZehnder_narrow_PowerSpectrum_Screenshot.png2um_MachZehnder_wide_PowerSpectrum_adjusted_Screenshot.png2um_MachZehnder_narrow_PowerSpectrum_adjusted_Screenshot.png 
  2393   Mon Aug 12 15:17:05 2019 KojiNoise Budget2micronLasersNoise Analysis of Voltage Regulator using SR785 Spectrum Analyser1. Heat: Check the polarity of the electrolytic
or tantalum caps. 

2. Add 0.1uF high-K ceramic caps
  
  2394   Tue Aug 13 16:53:57 2019 Nathan HollandElectronics2micronLasersPhase Noise of Brimrose AOM Driver (VCO).After reviewing the Brimrose AOM driver
mnual, yesterday, it turns out I was previously
using it incorrectly. It is a VCO with the frequency port
 20190813__Brimrose_AOM_Driver_phase_noise.pdf20190813__VCO_phase_noise_setup.pdfbrimrose_AOM_driver_VCO_phase_noise_spectra.hdf5 
  2395   Tue Aug 13 17:59:25 2019 Nathan HollandNoise Budget2micronLasersPhase Noise of Mach Zehnder with VCO.Following up from my previous
post I measured the phase noise
of the Mach Zehnder setup with the AOM driven
 20190813__Phase_Noise_Measurement_VCO_setup.pdfMachZehnder_w_AOM_Driver_085_20190813_102449.li20190813__MachZehnder_w_VCO-phase_noise.pdf20190813__MachZehnder_w_VCO-frequency_noise.pdf 
  2396   Tue Aug 13 19:03:05 2019 Shalika SinghNoise Budget2micronLasersNoise Analysis of Voltage Regulator Circuit using SR785 Spectrum AnalyzerAs it was observed that normal voltage
supply is noisy and not suitable for our
circuit, we plan to use a voltage regulator
 regulator.pdfNoise_across_Voltage_Regulator.pdfregulator.zip 
  2398   Wed Aug 14 16:07:57 2019 Nathan HollandDailyProgress2micronLasersNew AOM Driver.After reproting phase noise issues with
the VCO, here,
I have changed the VCO for a high power
 20190814__Phase_Noise_Setup.pdfMachZehnder_measured_phase_noise-LO_path__20190814.pdfMachZehnder_measured_phase-IFO_path__20190814.pdfMachZehnder_measured_phase-IFO_path_zoom__20190814.pdf 
  2399   Wed Aug 14 19:50:37 2019 Shalika SinghNoise Budget2micronLasersNoise analysis of Sallen Key filter using SR785 and Zero simulationThe photodiode needs a 1V bias so for a
clean bias we have decided to use a sallen
key low pass filter with a cut off frequency
 sallenkeyfilter.pdfTransfer_function_of_sallen_key.pdfNoise_across_SallenKey.pdfsallenkey.zip 
  2400   Thu Aug 15 02:30:29 2019 KojiSummary2micronLasersInAsSb PDs accomodated in PD housings / PD cablesInAsSb PDs were housed in the PD cages.
The cages were engraved to indicate the batch
(Sb3512 or 3513) and the serials (A1, A2,
 9x 
  2401   Thu Aug 15 08:03:13 2019 ranaNoise Budget2micronLasersNoise Analysis of Voltage Regulator Circuit using SR785 Spectrum AnalyzerI'm glad to see that the voltage regulators
can give good noise performance. I wish I
understood what the gain peaking features
  
  2402   Thu Aug 15 08:36:29 2019 ShalikaNoise Budget2micronLasersNoise Analysis of Voltage Regulator Circuit using SR785 Spectrum AnalyzerI found only 1uF Tanatalum Capacitors in
the EE shop. Maybe a a higher capacitance
of tantalum capacitor will help. 
  
  2404   Fri Aug 16 01:28:28 2019 KojiSummary2micronLasersSwitchable breakout bokDB9 switchable breakout box is ready. We
are ready to do some PD test now.
 P_20190815_210355.jpgP_20190815_210419.jpg 
  2407   Fri Aug 23 12:45:08 2019 Shalika SinghNoise Budget2micronLasersNoise Analysis of Circuit using SR785 Spectrum Analyser and Zero SimulationThe circuit has been soldered(refer entries
2399) and the noise for Sallen Key was
analyzed
 sallenkeyfilter.pdfbodeplot_sallenkey.pdfNoise_across_SallenKey.pdfsallen.zip 
  2408   Fri Aug 23 14:15:58 2019 DuoNoise Budget2micronLasersNoise Analysis of Circuit using SR785 Spectrum Analyser and Zero SimulationI think this is a solid measurement.




  
  2409   Fri Aug 23 17:35:37 2019 KojiNoise Budget2micronLasersNoise Analysis of Circuit using SR785 Spectrum Analyser and Zero SimulationThe TF looks good. But the noise measurement
is obviously limited by the SR785 noise.
We need a preamp, which is only for the purpose
  
  2411   Wed Aug 28 21:25:20 2019 Shalika SinghNoise Budget2micronLasersNoise Bump observed at 8kHz during TIA noise analysisThe noise analysis for TIA was done. The
circuit was in open but kept away from SR785
(to avoid any noise effect)
 circuit.jpgcircuit_setup.jpgNoise_across_TIA_op27.pdfNoise_across_TIA_LT1792.pdfTIA.zip 
  2412   Thu Aug 29 15:36:49 2019 KojiNoise Budget2micronLasersNoise Bump observed at 8kHz during TIA noise analysisYou need to check the voltage noise of
the regulator outputs with the opamps connected.
Probably you did it. If so, it is a riddle
  
  2413   Fri Aug 30 05:11:11 2019 ChrisNoise Budget2micronLasersNoise Analysis of Voltage Regulator Circuit using SR785 Spectrum AnalyzerIn case we need to seek a further reduction
in the voltage regulator noise, Wenzel has
kindly published their ideas
  
  2424   Mon Sep 23 23:48:12 2019 KojiUpdate2micronLasers2um sensor cards / focusing opticsFiber Collimator (Thorlabs F028APC-2000+AD11F+LMR1)
and MIR sensor cards (Thorlabs VRC6S Qty2)
were delivered.
 IMG_8936.jpg 
  2446   Fri Nov 15 20:10:00 2019 KojiSummary2micronLasersInAsSb PD Mounts designed

  
  2474   Tue Dec 10 16:35:03 2019 AidanLaser2micronLasersCalibrated cryo-PD REF PD output in units of power incident on cryo chamber windowWe placed a power meter after the fiber
collimator, 75mm focal length lens and HR
mirror at 45 degrees - basically, we placed
  
  2612   Wed Jul 21 13:14:11 2021 PacoLab Infrastructure2micronLasersBrimrose AOM and amplifierYesterday I came in the QIL and performed
an express kidnapping of the 2um in fiber
AOM (Brimrose) and the 5 W RF amplifier that
  
  2640   Fri Aug 6 16:15:03 2021 PacoLab Infrastructure2micronLasersBrimrose AOM and amplifierAlso borrowed Mini-Circuits amplifier ZFL-500LN+
from same setup.

  
  2675   Sun Oct 3 08:22:49 2021 AidanSummary2micronLasersStarting data taking and second test of JPL PD A1
Output going to JPL_PD/data/A1_test2
and DAQ
Test commenced at 8:20AM
and cryo cooler started shortly afterwards
Once
  
  2676   Wed Oct 6 13:50:18 2021 AidanSummary2micronLasersStarting data taking and second test of JPL PD A1
Turned cryocooler off around 1317588441
(about 1:46PM)
Restarted measurement
with output going to JPL_PD/data/A1_test3
Room
  
  2677   Thu Oct 7 08:07:03 2021 AidanSummary2micronLasersStarting data taking and second test of JPL PD A1
We're at 164K as of 8AM this
morning.
  
  2678   Mon Oct 11 08:35:21 2021 AidanSummary2micronLasersStarting data taking and second test of JPL PD A1Terminated the data taking at 8:35Am this
morning. The termperature traces of the cryo
chamber show a couple of discontinuities
 Screenshot_from_2021-10-11_08-36-06.png 
  2679   Mon Oct 18 15:25:14 2021 AidanSummary2micronLasersStarting data taking and second test of JPL PD A1Initial running of analysis code puts the
max QE at ~62 + /- 1% around 130-150K. I
want to explore this temperature regime manually
  
  2513   Fri Nov 6 08:14:58 2020 AidanUpdate2um PhotodiodesPhotodiode testing recovery statusQuick update, more detailed update to follow.


Laser is working
Photodiode
sweep with the Keithley shows a sensible
  
  2514   Fri Nov 6 12:45:21 2020 AidanUpdate2um PhotodiodesPhotodiode testing recovery statusEmbellished Chris's PD MEDM screen
a bit to illustrate controls in a diagram.
The representation of the RELAY SWITCH between
 MEDM.pngPD_sweep.png 
  2516   Mon Nov 9 15:49:58 2020 AidanUpdate2um PhotodiodesJPL PD resurrection (cont.)Okay - all the steps in the procedure of eLOG
2476 have been verified as working
  
  2517   Tue Nov 10 12:46:34 2020 AidanUpdate2um PhotodiodesJPL PD resurrection (cont.)Looks like the temperature difference between
the PD and the shield is relatively small.
Even the transients when the heater is applied
 temperature_diff_shield_v_PD.png 
  2519   Tue Nov 17 17:51:44 2020 AidanUpdate2um PhotodiodesAgilis piezo mirror installed in JPL PD testing apparatus I installed the Agilis mirror before the
lens and cryo-chamber. Used the USB interface
to align the beam onto the PD. So we can
 IMG_9401.jpgIMG_9400.jpg 
  2520   Thu Nov 19 16:25:30 2020 AidanUpdate2um PhotodiodesAgilis piezo mirror installed in JPL PD testing apparatus Here's the python code I used to control
this. 

I incorrectly used the Move to
 Screen_Shot_2020-11-19_at_4.27.17_PM.png 
  2533   Wed Mar 3 16:14:18 2021 AidanUpdate2um PhotodiodesBringing 2um PD testing back onlineI ran the bright PD test on the photodiode
currenlty in the vacuum chamber. The test
was run at air and room temperature. I aligned
 Screen_Shot_2021-03-03_at_4.11.47_PM.png 
  2534   Thu Mar 4 13:37:51 2021 AidanUpdate2um PhotodiodesReference PD reading vs Power incident on viewportI measured the power incident on the cryo
chamber viewport and the reference PD reading
to calibrate the incident power. Data is
 POW_IN_vs_REF_PD.csvIMG_1107.jpg 
  2535   Thu Mar 4 16:12:26 2021 AidanHowto2um PhotodiodesJPL PD set up tutorial videoI recorded a
15 minute overview that describes the
JPL PD set up and how to operate it. I'm
  
  2536   Wed Mar 10 17:20:26 2021 AidanUpdate2um PhotodiodesPumped chamber down briefly - connected vacuum gauge to the computer
I updated the SR560 settings for
the AC Photodiode readout going into the
ADC. They're now: AC coupled input, 2000x
 IMG_1204.jpgIMG_1200.jpgIMG_1191.jpgIMG_1190.jpgIMG_1199.jpg 
  2538   Fri Mar 12 16:29:36 2021 AidanUpdate2um PhotodiodesVacuum needs leak checkingI pumped the small vacuum volume down but
the pressure started rising as soon as I
turned off the vacuum pump. Closing the main
 Screen_Shot_2021-03-12_at_4.28.54_PM.png 
  2539   Tue Mar 16 18:45:43 2021 AidanDailyProgress2um PhotodiodesCryo cool down and temperature rise - JPL PD LN2 (5 hours to rise)I pumped the chamber down and added LN2
today. The pressure was slowly rising - it
was about 20m Torr in the chamber when I
 Screen_Shot_2021-03-16_at_6.44.09_PM.pngIMG_1397.jpgScreen_Shot_2021-03-16_at_7.09.34_PM.png 
  Draft   Thu Apr 1 20:28:26 2021 RadhikaDailyProgress2um PhotodiodesOpened cryo chamber and removed old PD04/01/21

Aidan and I removed the old PD from
the cryo chamber in order to start testing
  
  2550   Thu Apr 1 20:54:57 2021 RadhikaDailyProgress2um PhotodiodesOpened cryo chamber and removed old PD04/01/21

Aidan and I removed the old PD
from the cryo chamber in order to start testing
 7x 
  2553   Fri Apr 9 16:23:22 2021 ranaDailyProgress2um PhotodiodesOpened cryo chamber and removed old PDTo aid in taking photos of these diodes,
I put a USB microscope on Anchal's desk
- you can grab it from there. I use it with
  
  2554   Tue Apr 13 11:48:04 2021 RadhikaDailyProgress2um PhotodiodesOpened cryo chamber and removed old PDI posted a video tutorial of the diode
replacement.

https://dcc.ligo.org/G2100807
  
  2556   Fri Apr 16 11:27:01 2021 AidanUpdate2um Photodiodes2um DC photodiode voltage weird drift with no incident power[Aidan, Radhika, Nina]

We noticed that the DC channel
readout (FM30) of the JPL A1 photodiode is
 DC_2um_voltage_weirdness.png 
ELOG V3.1.3-