Quantitative 3D Diffractive Optics for Tunable Lattice Symmetry in Blue‐Phase Liquid Crystals.

Blue‐phase liquid crystals (BPLCs) possess unique 3D periodic chiral structures and extraordinary optical manipulation capabilities, demonstrating considerable potential in flexible displays, high‐security encryption, and intelligent sensors. Despite lattice deformations of BPLCs widely exist in various applications, there remains a challenge to understanding the quantitative relationship between different deformation modes and resulting 3D diffractive optics. Herein, a universal simulation strategy is proposed based on spatial geometry modeling to enable real‐time computation of dynamic optical responses in BPLCs. This framework systematically interprets and predicts the optical characteristics under both symmetric lattice deformations (governed by chiral dopant concentration) and asymmetric lattice deformations (induced by phase separation or component dispersion). Differentiated nonlinear optical effects are revealed for these deformations in Kossel diffraction analysis. Furthermore, anisotropic modulation of surface/sectional structural colors (photonic bandgaps) and angle‐dependent control over the full spatial light field is demonstrated by tailoring interplanar spacing and facet orientation within the lattice symmetry constraints. This study establishes a theoretical foundation for designing next‐generation BPLC‐based photonic devices, including holographic displays, all‐optical switches, integrated waveguides, and 3D lasing systems. [ABSTRACT FROM AUTHOR]