Special Issue: Soft Photonic Crystals and Metamaterials.

The paper strives to reduce the threshold until sunlight showing the dye doping has a great impact on the optical Fréedericksz transition, and that the host liquid crystal type also plays an important role. The threshold light intensity in trifluorinated liquid crystals is shown to be 42% lower than that in liquid crystals without fluorine substituents. Fréedericksz transition in liquid crystals is one of the most classic and important concepts with real applications for liquid crystals in the society. Soft matters include polymers, liquid crystals, colloids, biological tissues, and many smart materials. [Extracted from the article]