NAOJ GW Elog Logbook 3.2
Input polarisation 0 0 :
-without sample :Wed, Jun 26, 2024 8-28-22 AM.txt
-with QWP : Wed, Jun 26, 2024 8-31-55 AM.txt
Input polarisation 15 0 :
-without sample : Wed, Jun 26, 2024 9-09-25 AM.txt
-with QWP :Wed, Jun 26, 2024 9-19-36 AM.txt
Input polarisation 30 0 :
-without sample : Wed, Jun 26, 2024 10-15-42 AM.txt
-with QWP : Wed, Jun 26, 2024 10-23-04 AM.txt
Input polarisation 45 0 :
-without sample : Thu, Jun 27, 2024 9-55-00 AM.txt
-with QWP : Thu, Jun 27, 2024 12-20-38 PM.txt
Input polarisation 60 0 :
-without sample : Fri, Jun 28, 2024 9-33-51 AM.txt
-with QWP : Fri, Jun 28, 2024 9-38-24 AM.txt
Input polarisation 75 0 :
-without sample : Fri, Jun 28, 2024 10-16-40 AM.txt
-with QWP : Fri, Jun 28, 2024 10-19-00 AM.txt
Input polarisation 90 0 :
-without sample : Fri, Jun 28, 2024 11-10-10 AM.txt
-with QWP : Fri, Jun 28, 2024 11-13-12 AM.txt
Logan, Michael
We planned out a simple setup to mode match into the OPO (beam size 25.5 um before placement). We place f = 40 at z = 65 in and f = 75 at z = 71.6 in (screw holes relative to laser head). The beam size is then ~ 25um at z = 79, a slightly more comfortable spacing than last time the OPO was tested (maybe 5 cm extra). We have enough space to put both steering mirrors after the lenses and then put a 50/50 BS between the lenses to send to reflection PD (PDA05CF2 RFPD was used last time).
We checked using the mode matching telescope that the beam waists are approximately the correct places and the waist after f = 40 is about the right size (~40 um). Then we tried to optimize the mode matching at z = 79 but couldn't get below ~ 40 um radius.
We inserted Newport 4003 Resonant IR EOM somewhere down the line (aligned with 94% transmission). Since it is coming out of the reflection of a PBS (s-pol) I didn't add a HWP. Perhaps it added a bit more optical path length than I expected, I didn't check carefully in the clean room. From online search afterwards, the crystal is 4 cm long and made of Mg:LiNbO3 with a 25 C 1064 nm refractive index of 2.15. So it adds an extra ~ 4.5 cm (1.8in) of optical path and the initial positioning was a bit too far forward.
I'm not entirely sure if we have to lock, or if we even can lock before the Taiwan people arrive, but we might as well leave the EOM there anyway and see if we can lock by July 16. At the very least we should try to visualize good mode matching of the order used in the current OPO ( > 91% BAB to OPO). It is probably not worth the effort to test the loss using the AOM deflection method, since last time it was inconclusive due to the very fast ringdown. The only meaningful test of the new OPO loss will be inserting it into the squeezer.
average = 10 : Tue, Jun 25, 2024 5-43-40 PM.txt
average = 20 : Tue, Jun 25, 2024 5-45-29 PM.txt
average = 50 : Tue, Jun 25, 2024 5-48-34 PM.txt
average = 100 : \Tue, Jun 25, 2024 5-54-16 PM.txt
Input polarisation 0 0 :
-without sample : Mon, Jun 24, 2024 10-31-17 AM.txt
-with QWP : Mon, Jun 24, 2024 12-34-46 PM.txt
Input polarisation 15 0 :
-without sample : Mon, Jun 24, 2024 2-05-53 PM.txt
-with QWP : Mon, Jun 24, 2024 2-16-39 PM.txt
Input polarisation 30 0 :
-without sample : Mon, Jun 24, 2024 3-47-22 PM.txt
-with QWP : Mon, Jun 24, 2024 4-00-22 PM.txt
Input polarisation 45 0 :
-without sample : Mon, Jun 24, 2024 5-31-44 PM.txt
-with QWP : Mon, Jun 24, 2024 5-42-23 PM.txt
Input polarisation 60 0 :
-without sample : Tue, Jun 25, 2024 6-00-10 AM.txt
-with QWP : Tue, Jun 25, 2024 6-11-34 AM.txt
Input polarisation 75 0 :
-without sample : Tue, Jun 25, 2024 8-03-38 AM.txt
-with QWP : Tue, Jun 25, 2024 8-14-25 AM.txt
Input polarisation 90 0 :
-without sample : Tue, Jun 25, 2024 9-45-12 AM.txt
-with QWP : Tue, Jun 25, 2024 10-11-38 AM.txt
Restarted measurement without wait time and same parameters otherwise
by mistake the first few points were saved in the previous file..
I stopped the vi and restarted maesurement C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Coating measurement\AlGaAs\with hwp\Mon, Jun 24, 2024 2-27-30 PM.txt
There is no requirement to switch on wait time for any measurement. There is already an intrinsic wait time present in the labview logic. The external wait time is only to be switched on if you are doing stability measurement of the setup(for >~a day) and don't want to take measurement with high frequency. Unless there is a promising reason there is no use of switching on the external wait time for birefringence measurement of samples.
To confirm our AlGasAs birefringence measurement, we want to add a birefringent component between the BS and the coating.
I placed the HWP that was measured before (same roll angle as before).
Measurement from 0 to 3.5V with 0.1V step, LC temp is 30degC, 100 average and 1s wait time.
File is in : C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Coating measurement\AlGaAs\with hwp\Mon, Jun 24, 2024 10-47-05 AM.txt
There is no requirement to switch on wait time for any measurement. There is already an intrinsic wait time present in the labview logic. The external wait time is only to be switched on if you are doing stability measurement of the setup(for >~a day) and don't want to take measurement with high frequency. Unless there is a promising reason there is no use of switching on the external wait time for birefringence measurement of samples.
Restarted measurement without wait time and same parameters otherwise
by mistake the first few points were saved in the previous file..
I stopped the vi and restarted maesurement C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Coating measurement\AlGaAs\with hwp\Mon, Jun 24, 2024 2-27-30 PM.txt
I reinstalled the QWP and the HWP in order to get a circular polarization after the last mirror. And I add a polarizer on a motorized mount, just before the translation stage. Like this, we can get any linear polarization with enough power, without going into the clean room.
I put as sample a QWP, everything seems ready to start a measurement.
IMPORTANT : LIMIT VALUE ON Z AXIS == 23mm. (avoid to hit the polarizer)
[Shalika, Marc]
Measuring Jones Matrrix of AlGaAs coating
The sample is same as mentioned by Manuel in 746. We used the mounting technique as mentioned by Manuel in 746. But, we put in a mount where we can tune the alignment as well, i.e in a 2inch mirror mount. We first practiced putting a sample with no polish to see if the mount is fine. After being fully assured that the mount was indeed fine(like the screw will not touch the wafer or the wafer will not fall off, etc.), we then put the 0.5mm thick sampple. (pic1, pic2)
We setup a small clean room (taken from PCI). The AlGaAs was kept inside it. (pic3, pic4)
saving measurement from LC voltage scan in in:
C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Coating measurement\AlGaAs\20240621\Fri, Jun 21, 2024 3-12-57 PM.txt
I rotated the sample. Although its on non rotatble mount, I took a picture of the back surface for a reference of Sample 2 BB1EO3, before and after rotation.
C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Coating measurement\BB1-EO3 Sample2\20240619\Wed, Jun 19, 2024 6-42-43 PM.txt
With help of NOC
During last electrical shutdown a white CISCO wifi provider in TAMA storage stopped working.
Today we found out that its power supply got broken. Furthermore, NOC is not fully sure what are the 2 switches in the storage doing? Maybe old remnants.
In any case, NOC is responsible for the white CISCO wifi provider and the purple switch. The wifi source was moved and connected to the purple switch close to the DGS through POE and worked fine.
It can happen that the purple switch breaks during thunder or typhoon. A quick check would be to confirm if the LED is on on the white CISCO.
Replaced mirror with another sample of BB1EO3
10 avg: C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Coating measurement\BB1-EO3 Sample2\20240616\10 avg\Mon, Jun 17, 2024 11-30-53 AM.txt
100 avg: C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Coating measurement\BB1-EO3 Sample2\20240616\100 avg\Mon, Jun 17, 2024 9-08-21 AM.txt
Coming across the recent issues with labview and the several modifications, we saw that the observed characteristics of other components look better. Hence, we also chose to re-calibrate the BS
Pol states after LC without BS:
10 avg: C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Polarization states\20240613\Thu, Jun 13, 2024 4-52-27 PM.txt
100 avg: C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Polarization states\20240613\Thu, Jun 13, 2024 5-35-00 PM.txt
Flipped the BS and measure
with 100 avg: C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Beam Splitter Calibration\20240613\BackFaceRefl\10 avg\Fri, Jun 14, 2024 11-52-01 AM.txt
with 10 avg: C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Beam Splitter Calibration\20240613\BackFaceRefl\100 avg\Fri, Jun 14, 2024 1-22-15 PM.txt
The BS was flipped back to its original position
Pol states with BS :
10 avg: C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Polarization states\20240613\Sat, Jun 15, 2024 9-41-39 AM.txt
100 avg:C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Polarization states\20240613\Fri, Jun 14, 2024 10-54-07 PM.txt
Put camera in mirror reflection
I changed the mount of the mirror. Previously, I didn't notice, but I saw that when I rotated the mirror, the beam alignment changed(i.e the beam was rotating around a circumference of a circle) which could indicate that the way rotator mount is placed in the clamp mount, there is some inclination. To avoid discrepancy in considering normal incidence position, I changed the mount to using the mirror mount which is ideally used.
BB1EO3 sample old :
10 avg: C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Coating measurement\BB1-E03\20240615\10 avg\Sat, Jun 15, 2024 8-17-41 PM.txt
100 avg: C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Coating measurement\BB1-E03\20240615\100 avg\Sat, Jun 15, 2024 5-26-09 PM.txt
Replaced mirror with another sample of BB1EO3
10 avg: C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Coating measurement\BB1-EO3 Sample2\20240616\10 avg\Mon, Jun 17, 2024 11-30-53 AM.txt
100 avg: C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Coating measurement\BB1-EO3 Sample2\20240616\100 avg\Mon, Jun 17, 2024 9-08-21 AM.txt
I rotated the sample. Although its on non rotatble mount, I took a picture of the back surface for a reference of Sample 2 BB1EO3, before and after rotation.
C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Coating measurement\BB1-EO3 Sample2\20240619\Wed, Jun 19, 2024 6-42-43 PM.txt
The format of saving is of the form:
X, Y, Ellipticity, Azimuth, Power, s1, s2, s3
-took small map without sample for reference : Thu, Jun 13, 2024 1-42-34 PM.txt
-with a ILM sapphire as sample : Thu, Jun 13, 2024 1-49-37 PM.txt
tuned input polarization to 0 deg in azimuth and ellipticity :
-took small map without sample for reference : Thu, Jun 13, 2024 3-02-11 PM.txt
-with a ILM sapphire as sample : Thu, Jun 13, 2024 3-07-04 PM.txt
I took this subvi for granted and didn't notice this before. But, it seems there always has been a discrepancy in the voltage. It means that there is a high possibility that the input voltage used for calibration and for characterizing the optics were never same.
I am not sure what was the logic used in making the "dual step voltage" VI to change the voltage of LC but it is very problematic. It doesn't have 1mV resolution. Whenever I want to change the voltage from 0-3.5 V with 0.1V step, all of a sudden the voltage supplied starts becoming random numbers like 0.214. I don't understand how can it happen!
This needs to be changed because it means voltage applied is random!
Also, for future its advisable to not add stuff in VI if it can't generate perfect requirements!
I took this subvi for granted and didn't notice this before. But, it seems there always has been a discrepancy in the voltage. It means that there is a high possibility that the input voltage used for calibration and for characterizing the optics were never same.
-took small map without sample for reference : Wed, Jun 12, 2024 2-27-13 PM.txt
-with a QWP as sample : Wed, Jun 12, 2024 2-47-47 PM.txt
tuned input polarization to O ellipticity and 45 deg azimuth :
-took small map without sample for reference :Wed, Jun 12, 2024 3-37-50 PM.txt
-with a QWP as sample : Wed, Jun 12, 2024 3-54-04 PM.txt
I checked the TAMA microscope.
It is Olympus model GX51 with light source U-LH100-3 and cooled CCD camera BU-50LN.
It also comes with few ND filters.
The microscope is working fine. The camera aswell. I could installed the japanese driver and software on my laptop (for some reason the english version did not work).
HWP
at 0 deg with 10 avg: C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Retarder\HWP\20240611\0 deg\10 avg\Tue, Jun 11, 2024 5-38-05 PM.txt
at 0 deg with 100 avg: C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Retarder\HWP\20240611\0 deg\10 avg\Tue, Jun 11, 2024 9-18-38 PM.txt
at 38 deg with 10 avg: C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Retarder\HWP\20240611\38 deg\10 avg\Wed, Jun 12, 2024 12-31-12 PM.txt
at 38 deg with 100 avg: C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Retarder\HWP\20240611\38 deg\100 avg\Wed, Jun 12, 2024 9-56-56 AM.txt