Liquid crystalline blue phases (BPs) show excellent potential for application in tunable photonic devices because they possess the unique optical property that the selective 3D Bragg diffraction in a visible wavelength region can be continuously shifted using an electric fi eld. A new approach to simultaneously extend the wavelength range of fi eld-induced Bragg diffraction shift and the temperature range of thermodynamically stable BPs is critically needed. Here, a new BP material system is shown using a dendron molecule to extend simultaneously the two BP ranges. One is the temperature range of thermodynamically stable BPs, which is expanded from 2.1 to 4.6 ° C. The other is the reversible maximum shift range of Bragg wavelength on the electric fi eld, which is extended from 85 to 109 nm. The physical mechanism of the dendron-stabilizing effect in BPs is discussed in terms of elastic property and orientational order of liquid crystal molecules.

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