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ID Date Authorup Type Category Subject
  1705   Sun Jul 1 01:33:57 2012 ranaElectronicsIodineTemp controller design re-revised

  I hope that 298 K is not the designed equilibrium temperature...

  1728   Fri Aug 10 15:57:03 2012 ranaLaserGYROnoise spectrum with servos switched


 My understanding is that the next step is to squash the transmitted power fluctuations which you believe to be related to the source of the gyro noise?

  1731   Sat Aug 11 11:51:51 2012 ranaLaserGYROCW_TRANS intensity noise testing

 My first impulse is to say that you should set up a dual DC coupled ISS using the trans light as the reference. Same as what Tara & the 40m should have.

For the secondary, you can actuate on the amplitude of the drive to the AOM. For the primary, I guess you have to do an EAOM setup like Tara (or just take his setup!).

Is it better to use SR560's for this or some more PDH2 boxes or to start modifying the TCS boxes?

  1747   Fri Aug 24 15:47:22 2012 ranaLaserGYROPDH2 locking attempts


 How about a high Q LC notch instead?

  1757   Tue Sep 4 10:31:50 2012 ranaElectronicsGYROMarconi phase noise vs deviation


 I wonder what the measurement noise is in this case; what's the noise level you measure using the same oscillator for both the RF and LO inputs?

Also, why isn't the case with both oscillators locked to the same Rb clock relavent? You can use one of them to drive the AOM and the other one to do the PLL. In that case, you need some modulation enabled on both, however.

The RAM noise cancellation is very juicy. How come you can't just use a servo to feed the signal into the error point of one of the loops?

  1767   Thu Sep 13 10:20:36 2012 ranaElectronicsGYROExcess demod noise


 Seems like if you fix this excess RFPD noise, you could then lower the laser power and not be saturating the mixer. What is the output noise of the RFPD?

  1777   Fri Oct 5 04:40:51 2012 ranaLaserGYROgyro frequency noise monitor set up


 That's great news - there is now a way to measure all the noise. I would be surprised if you can do any better on the frequency noise readout without whitening. You should try subtraction with it as is.

  1804   Wed May 1 21:47:20 2013 ranaElectronicsFiberBeat delay line transfer function


 The delay line should be much longer.

Its OK for the signal to wrap my multiple wavelengths before recombining. After the mixer, the signal should have a termination and low pass and then go into a LT1128 with a gain of 50-100.

In principle, you can get the RFPD noise to be larger than the mixer noise and so you could also get away with an OP27. Probably Zach has a noise spec in terms of Hz/rHz that he wants to meet.

  1808   Fri May 3 01:15:15 2013 ranaElectronicsFiberBeat delay line transfer function


 This is OK. Better to use a 1.9 MHz low pass after the mixer. And the SR560 should have a gain of 10, since it has a fixed output noise. Change the low pass to double at 30 kHz.

  1840   Mon Jun 3 18:57:34 2013 ranaComputingGeneralHow to make high quality plots in Matlab



hplot = loglog(ff        , ligo,...
               virgo(:,1), abs(virgo(:,2)),...
               aligo(:,1), aligo(:,2),...
               ff        , abs(h_tama),...
               kagra(:,1), kagra_m,...
               geo(:,1)  , geo(:,2),...
               et(:,1)   , abs(et(:,2)));

grid minor
%axis tight
hXLabel = xlabel('Frequency [Hz]');
hYLabel = ylabel('Magntiude [m/m]');
axis([.01 110 1e-14 110])

%% custom color setting of individual traces by RGB number
colorss = {[0.5  0.5  0.5],
           [0.8  0.3  0.7],
           [0.0  0.0  1.0],
           [0.97  0.1  0.0],
           [0.1  0.9  1.0],
           [0.2  0.8  0.1],
           [0.4  0.4  1.0]};
for k = 1:length(hplot)
    set(hplot(k), 'Color', colorss{k});

hLegend = legend('initial LIGO',...
    'Adv LIGO',...
    'TAMA SAS',...
    'Einstein Telescope',...

% =======================================================
% this section uses the matlab handles to set all the Font and FontSize properties --- adjust to your taste
set(hplot, ...
  'LineWidth'       , 4           )

set( gca                       , ...
    'FontName'   , 'Times'     , ...
    'FontSize'   , 38          );
set([hXLabel, hYLabel], ...
    'FontName'   , 'Times',...
    'FontSize'   , 38          );
set([hLegend, gca]             , ...
    'FontSize'   , 22          );
%set( hTitle                    , ...
%    'FontSize'   , 12          , ...
%    'FontWeight' , 'bold'      );

set(gca, ...
  'Box'         , 'on'     , ...
  'TickDir'     , 'in'     , ...
  'TickLength'  , [.02 .0] , ...
  'XMinorTick'  , 'on'      , ...
  'YMinorTick'  , 'on'      , ...
  'YGrid'       , 'on'      , ...
  'XColor'      , .1*[.3 .3 .3], ...
  'YColor'      , .1*[.3 .3 .3], ...
  'YTick'       , logspace(-14,2,9), ...
  'XTick'       , logspace(-2,2,5),...
  'FontSize'    , 38, ...
  'LineWidth'   , 1.5        );
% ==========================================================

%% Ridiculous pretty-print code
% --- tells Matlab to use this figure window size and respect this size for printing
orient landscape
set(gcf,'Position', [700 500 900 700])
opname = 'SeismicIsolations';
% print the file as a 600 DPI EPS color file - this preserves the vector graphics  
print('-depsc','-r600', [opname '.eps'])
% use the epstopdf command to convert from EPS to PDF without losing quality (makePDF.csh is designed to work on Mac and uses unsetenv to avoid Matlab's bad GS librarys)
[a,b] = system(['./makePDF.csh ' opname '.eps']);
if a ~= 0
    disp('PDF Generation Error')
Attachment 1: makePDF.csh
#!/usr/bin/env tcsh

epstopdf $1 --nocompress --autorotate=All
  1870   Mon May 19 22:19:21 2014 ranaLaserGYROSeismometer filtering

I think you got to use more seis channels to make a good RZ. The residual that you see is not the GUR noise, but due to improper cal matching and mis-orientation of the seismos. If you post the data somewhere or at least tell me how to get it, I can make a new misoFTW.m that should get lower noise.

An/or do f-domain sub.

  1876   Fri Jun 20 09:19:41 2014 ranaLaserGYROGyro noise better by 10x *NOPE*

 Also, try out using Sujan's median Welch PSD code to see if it estimates a lower noise spectrum. Its better when there are transients.


  1879   Sun Jun 22 12:38:44 2014 ranaElectronicsGYROMarconi noise measurement verification


 But, to be realistic, don't you have to use 2 Rubidium clocks to make the Marconi phase noise measurement? And shouldn't it be done at the real carrier frequency that you use for gyro?

Now that the intensity noise is low, is there a new NB plot? I forgot where the oscillator phase noise would show up.

In the Dmass noise analysis, I think the conclusion was that the intensity noise of the two lasers could somewhat be rejected, by just having a higher gain in the trans beat PLL. Is that not true for gyro?

  1881   Tue Jun 24 10:47:35 2014 ranaElectronicsGYROMarconi noise measurement verification

 That's remarkable. If the gyro signal can be read out from the 2nd loop error, with no 2nd loop locking, it means that the long term drift is well within the cavity linewidth. I guess I would still want to keep a long term drift servo. Where does the phase noise in this path show up now that the noise is better? Does this new intensity noise coupling change in the transmission beat if the 2nd loop gain is high? Usually we think PDH loops are first order insensitive to RIN because its a null servo, but that's not true if its a thermal effect or if there is a big offset in the loop.

  1892   Fri Dec 19 12:22:37 2014 ranaLab InfrastructureGeneraloverhead lights

I noticed that some of the ceiling flourescent lights are out. Since when have these ceiling lights been out?

I'll get in touch with PMA to come in and replace the ceiling lights as well as the half-broke wall scone lights.

  1893   Tue Dec 23 19:58:49 2014 ranaElectronicsM2 ISSM2 bias/readout board evaluation


 Re: the high ON resistance of the CMOS switches:

LIGO changed from using the MAX333 to the MAX333A or the ADG333A because they have an ON resistance of ~20 Ohms instead of ~200 Ohms. Its also a newer part, I think. There's no reason for us to have any 333 in our shop; better to chuck them and replace with 333A everywhere.

  1907   Sun Feb 22 01:49:11 2015 ranaMiscSeismometerFinding Modal Frequencies of Frame

Rubber handles give too much low pass action - use the plastic handle of a ball driver instead. For a more calibrated result, even better is to use the PZT buzzer w/ HV driver. Nic and/or Steve know where it is.

The SR785 data can be save by using "Output"-> "ASCII Dump".

Its also good to include a diagram of the frame with the location and direction of the accelerometer on it for future reference.

  1921   Mon May 11 18:38:14 2015 ranaMiscSeismometerANSYS Videos and Building Update

I would expect that there should be 2 more modes in here, with frequencies between 0.1 and 4 Hz. The lowest mode is the pitch mode and the 1.5 Hz one is the pendulum. There ought to be a transverse pendulum and also a yaw mode.

Maybe try again with more eigenfrequency resolution in the 0.1 - 5 Hz region ?

  1924   Wed May 20 21:33:36 2015 ranaMiscSeismometerThermal Enclosure concept

We want to make a thermal enclosure for the seismometer. The attached diagram shows the concept and I am hereby handing it off to Stephanie for the next stage of refinement.

Metal Panels: We want to put aluminum panels on the Bosch frame, fully enclosing it. The panels should be thick enough that the thermal gradients can be made small. My estimate is that ~2 mm thickness is good for that.  Although it would be easier to put the panels on the inside of the frame for the purposes of clamping the box to something, I think we ought to put the panels on the outside of the frame and figure out a clamping solution. The panels should also somehow be made to contact each other on the edges so that there is no significant thermal resistance between them. I hope that Stephanie comes up with something clever here.

Heaters: On the outside of the panels we want to put several resistive heaters. I don't have a vendor preference, but this type of flexible heater from Omega is what we want. It can deliver several Watts with 28 Vdc, is flexible, and can easily be attached to the panels. We should look for a few different vendors and pick one which matches our heating and size requirements. Another option is to use silicone rubber heaters. What's the advantage of one or the other? We will have to fabricate a heater driver electronics box based on the Crackle coil driver circuit. The BUF634 used there should be able to drive 200 mA at 13 V.

Foam: Then we want to wrap foam around the whole thing so that we're passively isolated from room temperature changes. The foam insulation also keeps the box warm when we heat it and so it reduces the heating power requirements. Take a look at the foam that is used in the CTN lab for the reference cavity insulation; that's what we want. I'm not sure where to get it though.

Temperature Sensors: We want to put several AD590 temperature ICs on the aluminum panel attached with thermal paste (something like Arctic Silver). We'll read them out using our own homebrew transimpedance circuit (a copy if the iLIGO RefCav temperature stabilization box) and use 1 or more of them in a digital feedback loop to stabilize the whole thing.


Heaters: According to the Watlow website, comparison between Kapton and Rubber heaters. Heating power of the Kapton = 3 W/cm^2 and Rubber = 1.5 W/cm^2. Kapton has a max temperature of 200C and Rubber has 260C. The Flexible Heater catalog from Watlow is very useful and it looks like they can suppy anything we need. I think we should get the silicone heaters with wirewound traces.

Attachment 1: ThermalEnclosure.pdf
  1926   Mon Jun 1 18:26:01 2015 ranaLab InfrastructureHVAChot spots in lab - hot air coming from Gyro table HEPA

Kate noticed that two spots were hot in the lab. The east and west ends of the Gyro optical table.

Just to check that she wasn't crazy, I checked that it was so. The HEPA filters are blowing hot air. The ones near the other table are not. I will contact someone.

Also, Kate has gotten the wall lights replaced as well as the laser safety sign light bulbs.

  1936   Tue Jun 16 17:09:46 2015 ranaMiscSeismometerThermal Enclosure concept

Some Foam Notes:

  1. http://built-envi.com/portfolio/hot-box-measurements-of-wall-thermal-performance/
  2. https://en.wikipedia.org/wiki/R-value_(insulation)

I've ordered some different kinds of foams and sealing tape from McMaster.

  1938   Thu Jun 18 22:24:31 2015 ranaElectronicsPD noiseResistor noise observations,analysis and inference

This is possibly nice, but please replace the EPS with PDF and make all of the fonts (including superscripts) larger than the text font. Then we'll be able to read this stuff.


  1958   Mon Jul 6 08:15:53 2015 ranaMiscTempCtrltemperature noise plot

Since its hard to find, here is a plot from Frank Siefert from years ago, showing the temperature fluctuations in a metal box compared to ambient and sensor noise.

Attachment 1: tempnoise_final.pdf
  1959   Mon Jul 6 13:27:48 2015 ranaMiscSeismometerInverted Pendulum links

Inverted Pendulum links:

  1. http://dx.doi.org/10.1063/1.1149783
  2. http://dx.doi.org/10.1016/j.nima.2007.08.161
  3. https://en.wikipedia.org/wiki/Inverted_pendulum
  1983   Fri Jul 17 18:12:36 2015 ranaMiscPD noisePD noise update

something seems bogus here...the suppression at 1 Hz is much more than the open loop gain. usually this is mathematically impossible...

  1988   Fri Jul 24 17:59:39 2015 ranaMiscSeismometerMini thermal enclosure test

I've ordered some thermal paste (should show up at the 40m on Wednesday) for the thermistors and 2 silicone heaters for the panels. The silicone heaters are from McMaster (picked by Megan) and should allow us to deliver ~15 W of heat to the panels if we wire them in series.

The heat capacity of Aluminum is ~0.9 J/g/K or 45000 J/K for a 50 kg chunk. With no heat loss, that means it ought to take (45e4 J)/(15 J/s) ~ 9 hours to heat up the whole thing. Which is OK for maintaining the temperature, but pretty painful from the standpoint of initial warm up.

Perhaps we ought to just use the power supply we used for the reference cavity heaters. That one is too noisy for any kind of precision measurement, but ought to let us test the time constants of the box.

  2011   Tue Jan 5 14:48:08 2016 ranaSafetyLab InfrastructureHVACheating and cooling

As noticed by Kate a few times last year, the north side of the lab has hot air comiing out of the HEPA vents and the south side has cold air. This seems to be a problem with the setpoints for the sensors or the hot water actuators.

Let's remember to call physical plant after the current roof leaking situation settles down.

  2026   Sun Feb 21 14:27:24 2016 ranaMiscPD QEMeasurement of the enhanced QE of the PD without glass window

My interpretation of this is that we get ~2% increase in the peak EQE for p-pol by doing the extra bounce. Is that correct? If so, its a pretty good result.

I wonder if you can do some more angles to see if there are any features in the angular dependence.

It would also be interesting to modify the beam size to see if there is any change in the EQE. What is the estimated beam size now in the x & y directions? Does the reflected beam overlap the first beam? It would be good if the 2nd reflection from the PD can be steered to not go back into the fiber.

For the circuit, the R=20 Ohms makes it nicely so that the PD bias voltage doesn't change that much, which is good.

Is there a diagram with the reflector in place?

Is it possible to use the camera to take an image of the reflection from the PD? I wonder if its Gaussian or messy.

What about repeating this experiment with the 1.5 micron laser now? Or maybe a HeNe where the IQE is lower?

  2058   Wed Aug 3 18:46:13 2016 ranaMiscScatterometerGathering parts: 1550 nm scatter rig


This entry from Dmass lists the high noise diode lasers we had in the cryo lab for 1550 nm. The Emcore 1772 that you picked up is one of the ones I was talking about.

There is a some info about it (here) on the CryoWiki, but the links there seem to be dead. I'm attaching what I think is the right datasheet. It claims a linewidth of 1 MHz, but that's inferred from the RIN measured at 850 MHz, so not really what we want.

In any case, I think this is a good laser to use for doing these tests.

Attachment 1: 1772-NM-40-02-FC-PM.pdf
1772-NM-40-02-FC-PM.pdf 1772-NM-40-02-FC-PM.pdf 1772-NM-40-02-FC-PM.pdf 1772-NM-40-02-FC-PM.pdf 1772-NM-40-02-FC-PM.pdf 1772-NM-40-02-FC-PM.pdf
  2059   Mon Aug 8 00:31:59 2016 ranaComputingGeneralWiki upgrade

ATF Wiki upgraded to 2016 Isabel version of Docuwiki. Theme updated to Bootstrap3 using the Extension/Theme plugin updater. All is well.

  2060   Mon Aug 8 17:05:28 2016 ranaMiscGeneralRaspberry Pi beam profiles: possible student project


UCLA project. Should we try to make one of these?

  2065   Tue Sep 20 22:19:54 2016 ranaMiscScatterometerGathering parts: 1550 nm scatter rig

I'd make a beam with a 0.5 mm waist in the sample and then translate the sample around so that we could measure scatter at various points.

If we use an InGaAs camera, we should be able to image it. If its too faint, we can make the imaging lens so that the PD only sees the image near the beam center.

  2068   Wed Oct 5 10:50:24 2016 ranaLaserFiberfrequency noise

This is a nice plot from https://doi.org/10.1364/OE.18.022781 (Kenji's laser noise paper) comparing the frequency noise of different papers. Worth comparing to when we plot frequency noise performance of the 2 micron lasers.

Attachment 1: oe-18-22-22781-g007.pdf
  2076   Thu Dec 8 20:43:44 2016 ranaLab InfrastructureGeneralLab flooding and AC control issues

Need to have a couple of room temperature sensors logged into the frames so that we can do long term lookback of the lab temperature.

What about those environmental sensors that Frank Seifert setup and Aidan or Antonio revived ?

  2080   Tue Jan 3 20:15:12 2017 ranaLaserTMTFfiber based laser phase noise measurements

The Folks at IIT Madras (Deepa, Shanti, and Anil) recommend making a heterodyne measurement instead to get away from the 1/f noise in the detector.

  1. Put an AOM in the short leg. 40 or 80 MHz would be a good choice. Use a good oscillator for this; unless you sit at the maximum for the J1 component you will be first order sensitive to the oscillator AM (true ?).
  2. Fiber coupled detectors should have a good response at RF frequencies. The 1811-FC is a good choice.
  3. The PD output is then put into a PLL, or you can just mix it down with the driving oscillator and record the phase fluctuations directly with the CyMac.
  2084   Sat Jan 28 13:02:40 2017 ranaThings to BuyCDScheap DAQ

Some more cheap DAQ interfaces, whether for coffee or in the labs without CyMac:


  2087   Wed Apr 19 10:57:42 2017 ranaLaserGYROlaser to Liyuan

NPRO from Gyro table lent to Liyuan for cavity ringdown / contamination tests.

  2089   Thu Apr 20 13:26:23 2017 ranaLaserTMTFDET-10 thoughts

The DET-10D is an extended InGaAs photodiode which is biased either using a battery or an external supply. On the schematic you can see that the diode is directly connected to the BNC cable.

According to the datasheet, the NEP is 1 pW/rHz. The shot noise in 600 uA is sqrt(2 * 1.6e-19 * 600e-6) = 14 pA/rHz, so we should be fine if the datasheet is accurate for f < 1 kHz (which I doubt).

14 pA / 600 uA => RIN = 2.3e-8

Where is this dark noise coming from???

The input referred noise of the SR560 is ~5 nV/rHz above 5 Hz. With the 50 Ohm resistor, that gives us an equivalent current noise of 100 pA/rHz (much worse than anything else in this circuit). It is also ~5x larger than the thermal noise of the 50 Ohm resistor.

You should use a wire-wound resistor instead of a sketchy terminator, and it should be ~1-3 kOhms. To keep from saturating the SR560, you'll have to AC couple it.

Attachment 1: DET10D.pdf
  2092   Wed Apr 26 18:40:30 2017 ranaComputingGeneralATF Wiki updated

to 2017-02-19b "Frusterick Manners" +CAPTCHA +Wrap +Upgrade +VideoShare +Gallery

  2108   Tue May 23 15:19:48 2017 ranaLab InfrastructureRF10 MHz reference distribution system planning

This is pretty close, but for the section that runs down from the cable tray to the breakout box, it needs to be fully enclosed. Something like this:


with steel U-clamps to hold it to the wall; clamps will have to be put into the wall with some anchoring. The elbow piece starts from the cable tray so that there is no exposed cabling between the cable tray and the box.

  2110   Tue May 23 16:59:39 2017 ranaLab InfrastructureRF10 MHz reference distribution system planning

FULLY ENCLOSED!!!!! less Mickey Mouse

  2142   Thu Jul 20 18:16:33 2017 ranaUpdateWOPOPhotodetector Dark Noise

Ugh - I deleted those 1000 bad plots. Just give us 1 trace per PD, all on one plot. Each trace should also include the model # of the PD. Just 'stuff we have laying around' is not useful.

Also, what are the requirements on the PD? Describe how these are computed.

  2148   Mon Jul 24 22:28:51 2017 ranaMiscGeneralELOG word wrap

I'm annoyed by the elog word wrapping. It seems to only happen in the ATF log, probably due to a misconfig in some .css file or the awade entry method does some fixed font stuff.

To get around this, use this link for the ATF log. It only shows the past 31 days and that search format seems to heal the bad wrapping.

  2153   Fri Jul 28 11:16:58 2017 ranaMiscGeneralELOG word wrap

Terrible word wrapping problem fixed by putting actual <return> into some awade entries instead of the shift-apple-option hotkeys that he was using before.

  2155   Mon Aug 7 15:09:35 2017 ranaDailyProgressScatterometerCalibrating the Camera

Fonts too small - and theres no such thing as negative BRDF.

  2183   Sun Nov 5 15:12:06 2017 ranaSummaryComputingdiaggui on Mac laptops

Its now possible to install DTT (aka diaggui) ont your personal laptop using macports. This would allow you to access data from the LIGO sites, the 40m NDS, as well as the W. Bridge sub-basement labs (once Jon and I set up a way to move the data to the CIT cluster and NDS it).

as usual with MacPorts, YMMV, but this way works for me on more than one machine:

  1. sudo port install gds (this starts installing a huge pile of dependencies and may take a long while - you may need a charger)
  2. It will install root5 and then while getting the gds package, it displays the error:
  3. Error: Failed to archivefetch gds: root5 must be installed with +python27.
  4. This is because the MacPorts package for GDS is misconfigured. So at this point you do:
  5. sudo port uninstall root5
  6. sudo port install root5 +cocoa+gcc6+graphviz+gsl+http+minuit2+opengl+roofit+soversion+ssl+tmva+xml+python27
  7. sudo port install gds

This works on my old laptop (El Capitan), but so far not on Sierra.

After that you can run diaggui to open up your old .xml files, look back at old data, etc.

  Draft   Sun Dec 10 04:48:59 2017 ranaComputingGeneraldokuwiki updated

I updated the ATFwiki to the latest version of dokuwiki. backup is in the usual place on nodus.


  2199   Wed May 23 20:38:10 2018 ranaSummaryWOPOTransformer coupled photodiodes

What is going on with this fossilized squeezing experiment? I reckon that there is a loss diagram out there somewhere. Le'ts see some ellipses and arches:


  2208   Fri Jun 29 17:33:44 2018 ranaDailyProgress2micronLasersPower Loss in Fiber Optic Cable

In order to pick a length, we'll have to go beyond this optimization and consider cost and acoustic sensitivity.

Also, we have to start by making a guess at the frequency noise PSD of this laser, and also what sensitivity we want the MZ to have, as well as the PD electronics noise.

Please upload a noise budget plot in units of Hz/rHz showing a bunch of these noises as well as the frequency noise sensing requirement. Every 2 meters of fibers means 1 less pizza, so we'd like to take the length down from 100 meters to roughly 10 meters.

  2235   Mon Aug 13 01:48:48 2018 ranaDailyProgressWOPOSR560 battery as a voltage supply

When powering from the SR560 bananananas, you should disconnect AC power, else it may produce extra lines due to the charger.


Here the detector is operating on the ±12 V lines provided out of the back of a SR560.


ELOG V3.1.3-