Effect of structural modifications on the switching voltage of a holographic polymer-dispersed liquid crystal lattice

The effect of temperature-induced variations of the nematic director field on the switching voltage of a 2D square holographic polymer-dispersed liquid crystal (HPDLC) lattice was investigated for a mixture prepared from UV-curable commercially available constituents. At temperatures far below the nematic-isotropic phase transition, the switching voltage is governed by the domain structure of the director field, while at temperatures close to the phase transition it is governed by elastic and dielectric properties of the liquid crystal (LC) material. The crossover occurs at the temperature at which a thin interface region between the LC domains and the polymer pilasters is melted into the isotropic phase. We also performed a comparative study of the square lattices recorded with the use of four and three coherent beams and resolved numerous differences in their structural and switching properties that arise from different spatial profiles of the associated interference fields.