Dual beam polarization interferometry for roll angular displacement measurement

This study presents a polarization interferometry-based technique for the measurement of roll angular displacement with high resolution and excellent stability. The proposed technique uses a polarization camera to detect the phases of a light beam passed through a birefringent crystal. Variations in the phase difference are used to determine the angular displacement of the birefringent crystal. The dual beam configuration of the proposed measurement scheme helps to overcome the effects of fluctuating incident angular displacement on measurements of roll angular displacement. In experiments, the proposed system achieved resolution of 0.58 arcsec within a 10-degree measurement range. Disturbance from the incident angular displacement was much lower than that of our previous technique measurement methods. This study also investigated the occurrence of nonlinear periodic system errors. The proposed technique offers several advantages over existing methods, including higher resolution, wider range measurement capabilities, and robustness against external disturbance.