LC dependent electro-optical properties of holographic polymer dispersed liquid crystals
Holographic polymer dispersed liquid crystals (HPDLC) have been fabricated from four different types of LC at a specific resin composition to optimize the electro-optical performance of the film. Among them, ZLI-3417-100 gave the lowest driving voltage (<2.5V/?m) and fastest response time (<10ms) which was interpreted in terms of high dielectric anisotropy (??) and low viscosity of the LC. However, diffraction efficiency of the film was a bit low due to the relatively small refractive anisotropy (?n) of the LC giving rise to a small mismatch of refractive index with resin. With regard to the LC content, 40% LC gave the greatest diffraction efficiency, whereas saturation time decreased with increasing content of LC, which emphasizes the viscosity reducing effect of LC.
dielectric anisotropy viscosity holographic diffraction grating polyurethane acrylate (pua)