Highly flexible and electrically controlled grating enabled by polymer dispersed liquid crystal

Liquid crystal (LC) materials have dielectric and optical anisotropy and are candidates for the preparation of electrically controlled tunable diffraction gratings. Flexible LC gratings have the advantages of high flexibility, light weight, small size, and attachability. At present, the electronically controllable flexible LC grating needs to be further studied. In this paper, polymer-dispersed liquid crystal (PDLC) is poured into the flexible cell made of ITO-PET, and 1D and 2D flexible PDLC gratings are prepared by the method of polymer-induced phase separation. It can realize the modulation of the grating diffraction order through an external electric field under different curvature radii, and it also has the characteristics of the low driving voltage, low saturation voltage, and fast response. The driving voltage and saturation voltage of the 1D flexible PDLC grating are 0.8 V and 12 V, the cell thickness is 5.2 μm, and the rise and decay times are 3.225 ms and 98.29 ms, respectively, the first-order diffraction efficiency at the center is 9.1%. For the 2D flexible PDLC grating, the driving voltage and saturation voltage are 2.5 V and 16.5 V, the cell thickness is 5.2 μm, the rise and decay times are 3.362 ms and 75.46 ms, respectively, the first-order diffraction efficiency at the center is 7.58%.