High-precision measurement on the extinction ratio of linear polarizers

The extinction ratio is an important optical parameter that determines the quality of the linear polarizers. Here, we propose a high-precision measurement method for linear polarization extinction ratio, which is based on two uniform and consistent unknown linear polarizers, an integrating sphere, a precision turntable, and a spectrometer. The precision turntable is used to change the relative angle between the two unknown linear polarizers. The Mueller matrixs with the optical parameters including relative angles of the two unknown linear polarizers are established, and the linear polarization extinction ratio is obtained by numerical calculation. This method does not require a reference linear polarizer with a high extinction ratio, nor does it require fine adjustment of the angle between the two unknown linear polarizers to obtain the maximum and minimum light intensity grayscale response of the detector, which has an important engineering significance for high-precision measurement of linear polarization extinction ratio.