1. We were having issues with our input polarization. It was observed that it didn't remain linear over long time period even though it was tuned using HWP and QWP at the start. So we placed a GT10C Thorlabs polarizer. The ellipticity after the polarizer was 0.09deg and power was around 1mW.

 

2. We fine-tuned our input polarization using HWP and QWP after it too to obtain linear polarization which remained undeviated over several hours of measurement.

 

3. The fast axis was measured and found to be 183.63deg so we rotated by 3.63 degrees and measured again to get Fig 2.

 

4. LC 2 is aligned with its fast axis and we obtained the final alignment of 179.96+/-0.39deg as shown in Fig 2 and Fig 3.

 

The position of LC as 3.63-0.04=3.59 degree has been finalised for now.

 

Specs:

LC temperature=30 deg

measurement resolution=13 deg

folder name

Fig 1--r'C:\Users\atama\OneDrive\LC-Experiment\Measurement Data\LC2_calibration data\fast axis 15'

Fig 2--r'C:\Users\atama\OneDrive\LC-Experiment\Measurement Data\LC2_calibration data\fast axis 16'