Fig. 1. Molecular formula of SD1

Fig. 2. Polarization absorption spectra of SD1 film before and after orientation

Fig. 3. Schematic diagram of experimental device

Fig. 4. Peak absorbance variation with erasing time for multiple repeated orientation of SD1 film

Fig. 5. Saturation degree variation with orientation time for multiple repeated orientation of SD1 film

Fig. 6. Relationship between saturation order parameter（a），orientation velocity（b）and cumulative energy density of exposure.

Fig. 7. UV-Vis absorption spectra of SD1-oriented films during repeated orientation

Fig. 8. UV-Vis spectral absorbance of SD1-oriented film variation with reorientation cumulative exposure energy density

Fig. 9. Comparison of UV-Vis absorption spectra of oriented films before and after exposure

Fig. 10. Absorbance variation of the stationary oriented film after the light source turned off