NAOJ GW Elog Logbook 3.2
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ShalikaSingh - 11:43, Thursday 02 May 2024 (3544)
Compensation of BB1EO3 at 0 deg
The Jones matrix of the coating BB1EO3 was measured at 3 position 0,14,62 deg. This matrix alongwith BS was used to combine with the input polarization states to find the optimum voltages for compenstion. The desired voltage afterwards were saved in the format where there were range of other voltages obatined using the first set of voltage as locus to create a square of half edge 20mV with step size 2mV.
The coating was moved to 0 deg.
The voltage file was fed to the labview "Complete Integration-File Choice"
The measurement will be started after stable temperature of LC is attained. (warm up time is ususally 30mins)
The laser will be kept on till next week. So, kindly don't turn it off.
The voltages for compensation can be found here:
foldername='C:\Users\atama\OneDrive\LC-Experiment\Measurement Data\Coating measurement\BB1-E03\20240417\0 deg\CompensationVoltage'
filename='voltagecompensating_0.02_0.002.txt'
File is being saved here after setting up new voltages
C:\Users\atama\OneDrive\LC-Experiment\Measurement Data\Coating measurement\BB1-E03\20240417\0 deg\AfterCompensation\Thu, May 2, 2024 12-12-22 PM.txt
The measurement stopped because of windows update. I have paused windows update for next 5 weeks.
Started another one with new voltage set of radius 50mV, step 5mV. The condition on ell and azi was 5 degrees.The measurment is being saved with 1 average.
voltage file is here:
C:\Users\atama\OneDrive\LC-Experiment\Measurement Data\Coating measurement\BB1-E03\20240417\0 deg\CompensationVoltage\voltagecompensating_0.05_0.005.txt
find the measurment file here:
C:\Users\atama\OneDrive\LC-Experiment\Measurement Data\Coating measurement\BB1-E03\20240417\0 deg\AfterCompensation\Sat, May 4, 2024 5-10-32 PM.txt
Couldn't transfer voltage file , a bit too huge
decreased condition to 20mV, 2mV and 2 degrees.
Also, I had made a mistake in conversion from rad to degree in the previous one , at one instance
voltage file:
C:\Users\atama\OneDrive\LC-Experiment\Measurement Data\Coating measurement\BB1-E03\20240417\0 deg\CompensationVoltage\voltagecompensating_0.02_0.002_2.txt
measurement file :
C:\Users\atama\OneDrive\LC-Experiment\Measurement Data\Coating measurement\BB1-E03\20240417\0 deg\AfterCompensation\Sat, May 4, 2024 6-05-39 PM.txt
Even though the voltages are being used from the file, it seems there could be a deviation, considering we did the calibration of LC 2 months ago. I can't see a zero crossing in azi and ell, also the file is a bit huge, so it will take longer than expected.
I am going to instead do scan using the voltage range estimated but without using the file, and doing first a rough scan, and then will later do a finer scan.
The voltage range estimated from characterization is 7-8 V for LC 1 and 0-25V for LC2 with condition of 2 degrees on azi and ell.
So, doing a scan from 6-9V with 0.2V step, and 0-25V, 0,2V step.
measurement file:
C:\Users\atama\OneDrive\LC-Experiment\Measurement Data\Coating measurement\BB1-E03\20240417\0 deg\AfterCompensation\Sun, May 5, 2024 2-44-03 PM.txt
(could see zero crossing in labview, still need to plot, measurement finished by the time I finished writing this elog)
Did scans from
LC1, LC1step, LC2, LC2Step, averaging
0-25V, 0.2V, 0-25V, 0.2V
then observed and put a constraint on ell and azi of 2 deg
second scan
0-1V, 0.01V, 0-25V, 0.1V
15-25V, 0.1V, 0-25V, 0.1V
third scan
0-0.06V, 0.01V, 0-8V, 0.05V
15-25V, 0.01V, 0-5.2V, 0.01V
15-25V, 0.01V, 5.2-8V, 0.05V
0-0.06V, 0.01V, 0-4.3V, 0.01V
4th scan
0-0.04V, 0.005V, 0.83-1.2V, 0.001V
15-25V, 0.005V, 0.83-1.2V, 0.001V
5th scan
14.99-15.02, 0.001, 0-2V, 0.001V
24-25V, 0.001V, 0.95-0.994V, 0.001V