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The particular thermally induced phase separation (TIPS) method was developed by using poly(N-vinyl carbazole) (PVK) dissolved in liquid crystal (LC) layer recently. Permanent scattering is produced via the particular TIPS due to the formation of poly-domain LCs. In this work, we applied the particular TIPS to a conventional cholesteric LC (CLC) device. A broadband CLC device with a poly-domain structure was demonstrated by using the particular TIPS of CLC and PVK. The CLC device fabricated by two indium tin oxide glass substrates coated with PVK films generated the rough PVK layers and microstructures when the device was cooled from a temperature higher than the clear point of CLCs. The produced poly-domain planar texture of CLCs still preserved the bistability. A high cooling rate and PVK concentration both increased the reflection bandwidth of the CLC devices.

A switchable liquid crystal (LC) Fresnel lens was demonstrated by the UV-modified alignment layer for producing an alternation of hybrid-aligned and vertically-aligned LC zones. A polarizationindependent Fresnel lens can be obtained by circular rubbing, and a high diffraction efficiency of ~23% is reached with a low driving voltage of 1.2 V.