A new optical polarizing prism extinction ratio measurement method based on heterodyne-detecting

We present a method for measuring the polarization extinction ratio of a prism with the heterodyne-detecting. The key of this method is converting the intensity difference of more than one million times between vertical and parallel polarized transmitted light to almost equal level, so as to overcome the difficulty of measuring the intensity of both vertical and parallel components in the linear response range of a normal photodetector without attenuation. Using this method, we have realized the measurement of a polarizing Glan-Taylor prism with extinction ratio of 60.4dB.