Birefringence mitigation (General)
ShalikaSingh - 19:57, Thursday 08 June 2023 (3273)
The Fast and Furious (Sequel 12)

Fast axis measurement of LC2. 

 

Investigating issues mentioned in 3269, I removed the LC and found that somehow the hwp and qwp before lc were not transmitting linear polarization. The beam was displaced in the yaw before even entering the box. This was corrected. This explains the absurd measurement of elog 3262

 

Seeing Fig 3 from elog 3269 (where the initial position was 13.58) I moved the LC by 15.41 degrees in antiCW and so the initial position was 358.17 deg. The measurement was done with this and the fast axis orientation obtained is as shown in Fig 1. This was done by 9deg resolution for rotation.

 

Since the beam changed its obvious that we can't compare this present results with past one. Rotating by 12.15 degree now should align LC to the fast axis. 

 

This fast axis measurement is becoming Mission Impossible. 

 

folder_name = r'C:\Users\atama\OneDrive\LC-Experiment\Measurement Data\LC2_calibration data\fast axis 12'

Images attached to this report
3273_20230608125707_17.png