Anisotropic Mechano‐Optical Properties of Chiral Nematic Liquid Crystal Elastomers with Uniaxial In‐Plane Helical‐Axis Alignment

This study investigates the mechano‐optical properties of chiral nematic liquid crystal (N ^* LC) elastomers with a uniaxial in‐plane helical‐axis alignment. We fabricate a freestanding N ^* LC elastomer by using a recently reported method. N ^* LC elastomers display anisotropic mechanical properties; elongation parallel to the helical‐axis alignment induces greater stretching than elongation perpendicular to the alignment, owing to changes in elastic energy associated with the helical pitch. Moreover, the elastomers exhibit robust mechano‐optical properties with strain‐dependent variations in the diffraction angle. In contrast to conventional achiral LC elastomers, the diffraction properties of the N ^* LC elastomers remain intact even under large strains (≈200%). Importantly, the elastomers exhibit polarization‐specific functionalities. Under linearly polarized light inclined at 0° or 90° to the helical axis or circularly polarized light, the polarization plane of the diffracted light is rotated by 90° or converted into circularly polarized light with the opposite handedness. These results indicate that the molecular alignment within the elastomer is well maintained under applied strain and contributes to its unique optical properties. The versatility of these materials highlights their potential for advanced applications such as optical sensors, flexible diffraction gratings, and novel polarization‐specific optical components.