Comparison of homogeneously- and hybrid-aligned liquid crystal microlenses optical properties

Optical properties of homogeneously- and hybrid-aligned liquid crystal (LC) microlenses with positive dielectric anisotropy have been researched. Focal length-voltage dependencies are similar for both types of LC-microlens. When voltage is low the microlenses possess focusing optical properties. The focal distance decreases with increasing voltage then becomes minimal and increases. At higher voltage defocusing optical properties are observed. The microlens focal distance decreases approximately asymptotically to a certain value. The numerical aperture decreases with increasing microlens diameter and is smaller for hybrid-aligned LC-microlenses compared to homogeneously-aligned ones