Fabrication principle and 3D display application of the LC microlens array (IMAGE)
Caption
a) Schematic of the UV exposure and phase separation processes. Above is a grayscale mask with a microlens array pattern. The bottom is a liquid crystal cell with a composite structure of a polymer layer and a liquid crystal layer with microlens array morphology. When a cell filled with the mixture of LC and prepolymer is exposed to a normally incident, collimated UV laser beam, an intensity gradient of the UV beam will be created inside the cell due to the strong absorption of UV light. By adding a designed photomask, an additional intensity gradient in the x-y plane of the cell will be then created as well. The monomers in the high-intensity regions will first undergo polymerization. The monomers and the LCs in the low-intensity regions will diffuse toward the high-intensity regions to maintain their relative concentration. With deliberate exposure conditions, long enough UV exposure eventually consumes all the monomers and causes LCs to move out of the polymerized volume. Meanwhile, the LC molecules will be also orientated by the alignment layer. As a result, the phase separation is anisotropic in three-dimensional space inside the cell. b) The photograph of a typical sample with an area of 5 cm ´ 5 cm under crossed polarizers. c) Schematic diagram of 3D image reproduction. A white light source illuminating the photomask serves as the display panel. The LC-MLAs were placed in front of the photomask. The objects “3” and “D” are reconstructed near the central depth plane. The central depth plane can be tuned by the LC-MLAs.
Credit
by Wenfeng Cai, Delai Kong, Zongjun Ma, Mengjia Cen, Jiawei Wang, Dandan Yuan, Ke Li, Ming Cheng, Shaolin Xu, Dan Luo, Yan-Qing Lu, and Yan Jun Liu
Usage Restrictions
Credit must be given to the creator.
License
CC BY