Tunable Liquid Crystal Lens Using Stacked Alignment Layers

A tunable liquid crystal (LC) lens is achieved using stacked alignment layers. The stacked alignment layer consists of photoalignable homogeneous alignment material and rubbed vertical alignment material. By controlling the dosage of the UV exposure, the pretilt angle can be controlled in the range of planar to vertical continually. By exposing the stacked alignment layer under UV laser, a lens-like phase retardation profile is got due to the spatially variable pretilt angle. The focal length of the LC lens is tunable in the range of 19cm to infinite along with the increase of voltage. The potential application of tunable LC lens is glasses free 3D display, digital camera lens, etc.