Optical addressing in dye-doped cholesteric liquid crystals

This work presents a simple and rapidly optical patterning method to address patterns in dye-doped cholesteric liquid crystals (DDCLCs). The CLC textures can be transferred from planar to focal conic textures by the photo-induced randomly adsorbed dyes. Using this optical patterning approach, LC displays and other devices, such as Fresnel zone plates, reflective grating can be demonstrated. The experimental result shows that the resolution of the device can achieve ∼ 5 μm. Notably, the display developed by the present technique can be adopted as the so-called smart card, because the addressed patterns are invisible initially, but become visible upon heating over and then cooling down to the room temperature, or applying a suitable voltage and release it rapidly. Additionally, the patters described above are thermally erasable, optically rewritable and electrically switchable.