Large Three-Dimensional Photonic Crystals Based on Monocrystalline Liquid Crystal Blue Phases (Postprint)
Journal Article - Open Access
NATIONAL SUN YAT-SEN UNIV KAOHSIUNG (TAIWAN) KAOHSIUNG Taiwan
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Although there have been intense efforts to fabricate large three-dimensional photonic crystals in order to realize their full potential, the technologies developed so far are still beset with various material processing and cost issues. Conventional top-down fabrications are costly and time-consuming, whereas natural self-assembly and bottom-up fabrications often result in high defect density and limited dimensions. Here we report the fabrication of extraordinarily large monocrystalline photonic crystals by controlling the self-assembly processes which occur in unique phases of liquid crystals that exhibit three-dimensional photonic-crystalline properties called liquid-crystal blue phases. In particular, we have developed a gradient temperature technique that enables three-dimensional photonic crystals to grow to lateral dimensions of 1 cm 30,000s of unit cells and thickness of 100 microns 300 unit cells. These giant single crystals exhibit extraordinarily sharp photonic bandgaps with high reflectivity, long-range periodicity in all dimensions and well-defined lattice orientation.