Real-time measurement of liquid crystal birefringence

This paper presents a methodology that utilizes the refractive index of liquid crystal birefringence using the Michelson interferometer optical path. By measuring the correlation between the change in the optical path of the liquid crystal during rotation and the resulting interference fringe pattern, the interference fringes are binarized. The changes in gray values during the fringe shift are used to facilitate precise counting the number of the fringes. Using this method, the thickness of a 235.0 μm LC cell sample was determined to be 229.6 μm, with a measurement error of 2.29%. The refractive index for the o light of E7 liquid crystal was found to be 1.5342, 1.5035, and 1.5166, with errors of 1.07%, 0.948%, and 0.085%, respectively. The refractive index for the e light was measured at 1.7126, 1.7132, and 1.7234, with errors of 0.903%, 0.866%, and 0.283%, respectively. The experimental results show that this method is simple, real-time application, and exhibits a high degree of accurate