Three-dimensional Observation of Lattice Structure in Blue Phase I by Using Confocal Laser Scanning Microscopy

<p>Blue phases (BPs) usually exist in a narrow temperature range between a chiral nematic phase and an isotropic one. They are believed to have the self-assembled three-dimensional (3D) cubic structures consisting of the cylinders formed by the double-twisted arrangements of liquid crystal molecules (Figure1) [1]. Physical properties of BPs, including the selective Bragg reflection in visible wavelength region and the fast electro-optical response, are attributed to the unique cubic structure with the lattice constant of several hundred nanometers. These properties bring about potential applications of BPs in electronic and photonic devices. Hence, verification of the BP lattice models is critical in the field of BP science. In this work, direct observation of lattice structure in BP I were carried out by the confocal laser scanning microscopy (CLSM), which was a novel and powerful imaging technique for obtaining high-resolution optical images in 3D scale.</p>