Fig. 1. Structure diagram of ferroelectric nematic devices and chemical molecular structure of materials.（a）Molecular arrangement diagram of RM734 in ferroelectric nematic phase in liquid crystal cell；（b）Molecular structural formula of RM734 and 5CB.

Fig. 2. POM image of phase transition process of RM734 ferroelectric liquid crystal during cooling（A：analyzer，P：polarizer）

Fig. 3. Ultraviolet-visible absorption spectrum measurement optical path diagram of the sample

Fig. 4. Ultraviolet-visible absorption spectra of E7 and RM734 in two phase states relative to the empty cell

Fig. 5. POM images of ferroelectric nematic phase irradiated by 365 nm ultraviolet light.（a）Color of partial polar domains turns green under 365 nm UV light；（b）Color of partial polar domains turns orange under UV light；（c）Isothermal phase transition from N_F to N under UV irradiation（A：analyzer，P：polarizer）.

Fig. 6. Ultraviolet-visible absorption spectra relative to empty cell when light exits at different polarization angles

Fig. 7. POM images of 365 nm UV-induced phase transition with different polarization directions.（a）The included angle between the light polarization direction and the liquid crystal molecular direction α=0°；（b）α=20°；（c）α=45°；（d）α=70°；（e）α=90°（A：analyzer，P：polarizer）.

Fig. 8. Phase transition time versus light irradiance at different polarization angles