Study On Polarization Modulation Characteristics Of Nematic Liquid Crysta Based On Phase Measurement

With its special physical properties,liquid crystal plays a very important role in many industrial and scientific research fields,in which nematic liquid crystal is the most widely used.The main optical application of liquid crystal comes from its special polarization modulation characteristics,which is of great significance to the research of liquid crystal optical polarization modulation characteristics.In this paper,the detection method of the liquid crystal polarization modulation characteristic is studied,and the current liquid crystal polarization modulation characteristic detection method and the liquid crystal related physical and optical properties are introduced and analyzed.Further,based on the theory of traditional liquid crystal detection method and PSA system,and based on the single axis bicrystal optical model of nematic liquid crystal under plane anchoring.A real-time multi-channel measurement scheme for molecular direction vector angle distribution and liquid crystal thickness distribution of liquid crystal samples using polarization camera is proposed and studied.The molecular direction vector angle distribution and thickness distribution of nematic liquid crystal samples can be calculated in real time by processing the images collected by polarization camera,and the polarization modulation characteristics of liquid crystal can be obtained by analyzing the molecular direction vector angle distribution and thickness distribution of nematic liquid crystal samples.This method avoids some problems in the traditional method.Such as the problem of machinery rotation,poor real-time performance and the distribution of liquid crystal samples to be measured must be uniform,and the real-time and effective detection can also be realized for the existence of uneven thickness distribution and angle distribution in the field of view.In this paper,the measuring principle and algorithm are expounded,and the formula is deduced theoretically and simulated by Jones matrix.The corresponding experimental system was built to prepare liquid crystal samples with different thickness distribution.Themethod was verified by experiments,and the measurement results were displayed and the error analysis was carried out,which showed that the method was accurate to a certain extent.The topic of this paper comes from the major national instrument project,which is of certain significance for the research and application of polarization modulation characteristics of liquid crystal devices.