NAOJ GW Elog Logbook 3.2
To address the issue mentioned in elog 3735, I am re-measuring the HWP
Since there is no place between the BS and AlGaAs coating to put both camera and HWP. I have place the polarization camera in the reflection of the BS and put beam dumb in transmission. This avoids removal of the AlGaAs and the issue of its realignment.
The measurement will begin from calibration in reflection of BS and then putting HWP in between camera and BS.
The voltage of LC = 0-3.5V with 0.1V step and 100 avg. The measurement will start after warm up time of 30min.
calibration file:
1. C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Retarder\HWP\20240917\0 deg\Tue, Sep 17, 2024 10-17-41 AM.txt C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Polarization states\20240917\Tue, Sep 17, 2024 11-53-11 AM.txt
I have also placed the empty rotator mount before the camera before the calibration to avoid any issue of interfering with the setup later. The HWP can later be mounted directly.
The linear input polarization states were filtered from the 1st calibration file. The condition was abs(ellipticity)<=2 degree. there was 145 sets of voltages.
voltage file name: C:\Users\ssing\Dropbox\LC-Experiment\Measurement Data\Scan voltage\LinearPol_20240917
2nd calibration with only linear Pol voltages (5 iterations, 100 averaging). Total Measurement time is around 25-30 mins.
C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Polarization states\20240917\Tue, Sep 17, 2024 6-51-22 PM.txt
Both the files are used to preapre results for comparing the reconstruction of birefringence from linear and arbitrary polarization states.
HWP was installed. Measurement file is as follows
Using calibration file 1:
C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Retarder\HWP\20240917\0 deg\Arbitrary Pol\Thu, Sep 19, 2024 3-00-50 PM.txt
Using calibration file 2 (linear Polarizations):
C:\Users\atama\Dropbox\LC-Experiment\Measurement Data\Retarder\HWP\20240917\0 deg\Linear Pol\Wed, Sep 18, 2024 6-24-03 PM.txt