Fig. 1. Brewster's law

Fig. 2. Interference principle of polarized light

Fig. 3. Measurement of refractive index of triangular prism

Fig. 4. Optical path for measuring polarization direction of polarizer.（a）Horizontal adjustment position of the spectrometer；（b）Measured extinction position of the spectrometer.

Fig. 5. Photoelectric test system

Fig. 6. Variation curve of transmittance with the angle between the polarization direction of the front polarizer and the front friction orientation of the liquid crystal cell

Fig. 7. Detailed experimental curve

Fig. 8. Variation curve of the effect of voltage on transmittance

Fig. 9. Variation curve of transmittance with the applied voltage

Fig. 10. Variation curve of transmittance with the time