High sensitivity roll angle measurement based on birefringent polarization interferometry

Abstract

This study developed a method for measuring roll angular displacement utilizing two laser beams incident on a birefringent crystal (BC). A polarization interferometer, comprising polarization elements and a polarization camera, measures variations in phase difference induced by the angular displacement of the BC. Roll angle displacement measurements of high accuracy are then obtained through algorithmic processing. The high sensitivity of the system to phase difference variations enables the detection of small roll angle displacements without the bulk associated with conventional interferometers. Uncertainty analysis confirmed the efficacy of the system, achieving a roll-angle measurement resolution of 3.88 × 10^-4°.