684349.fig.017
Figure 17: Schematic formation process of H-PDLC gratings. (a) Homogeneous mixture before exposure. (b) The exposure intensity distribution is sinusoidal. In the bright region, the monomer polymerizes first. The liquid crystal diffuses to the dark region. (c) Finally, alternate polymer-rich and liquid crystal region formed. The refractive index is modulated along -axis direction.