NAOJ GW Elog Logbook 3.2
[Shalika, Marc]
This measurement aims to find the fast axis orientation of our second LC so that we can align it correspondingly for future measurements.
1. The fast axis orientation was measured using the method mentioned in elog 3242.
2. Our setup is inside a box and so (sometimes the laser hits the box or because of lack of air circulation) the temperature gets unstable and affects the LC. So we decide to use LC at 30 degrees. This helps us avoid any temperature fluctuations.
3. The LC was rotated from 0 to 360 deg with increments of 45 degrees.
4. To understand our fast axis position our data (where power is observed for the LC rotation) was fitted properly to the equations. (see Fig 1) . This fit is then used to get fast axis orientation.
5. The axis was found to be at -22.3 degrees (see Fig 2) and so the LC has been rotated to this position. The LC position is now 337.8 degrees.
6. The measurement will be taken again to avoid any deviations from the best position, with 10 degree increments.
[we have tried taking this measurement 6 times as of now. We are a bit baffled by the mysterious nature of fast axis discontinuity. We will try to do this measurement with more points. ]
PS:
The data is stored in foldername= 'C:\Users\atama\OneDrive\LC-Experiment\Measurement Data\LC2_calibration data\fast axis 6'
The measurement was repeated. First, I moved the LC to the new position of 337.78 degrees. Then I repeated the measurement with the angle of rotation incremented by 30 degrees.
The issue with fast axis orientation continues. see Fig 1 and 2. It seems that there is a discontinuity at some points. This has been observed in almost all the 7 times that we did measurements.
PS:
The data is stored in foldername= 'C:\Users\atama\OneDrive\LC-Experiment\Measurement Data\LC2_calibration data\fast axis 7'