The dataset contains additional data for the experimental methodology of Blue Phase photonic crystals fabrication and electrooptical characterization.
Objectives: To realize large-area monocrystalline blue phase liquid crystal structures with a photonic stopband positioned outside the visible spectrum, enabling fully transparent operation while preserving the intrinsic optical isotropy of the cubic lattice. Using this platform, we demonstrate a polarization-independent phase modulator with sub-millisecond response times, highlighting the potential of monocrystalline blue phases for fast and transparent reconfigurable photonic devices.
Methods: Blue phase (BP) precursor mixtures were prepared using an in-house nematic host composed of fluorinated terphenyls, biphenyls, and cyclohexylbiphenyls combined with mesogenic monomers and the chiral dopant ISO(6OBA)₂. By carefully tuning the dopant concentration and employing weak anchoring alignment layers, large monocrystalline BPI(110) domains with controlled lattice orientation and size were reproducibly obtained while suppressing competing BPI(200) domains. The mixtures were filled into indium–tin–oxide coated glass cells (3–5 μm thickness), thermally cycled to induce blue phase formation, and subsequently polymer-stabilized by UV irradiation. Phase behavior and crystallographic orientation were investigated using polarized optical microscopy, reflection spectroscopy, and Kossel pattern analysis supported by diffraction simulations to extract lattice parameters. Electro-optic performance was evaluated using a Mach–Zehnder interferometer to measure voltage-dependent phase modulation, while broadband reflection spectroscopy was used to monitor photonic stopbands and their stability under controlled irradiation conditions.
Results: Directional lasing from millimeter-scale stabilized monocrystalline BP photonic crystals is shown a significant advance, as only random lasing from polycrystalline samples has been previously observed. These structures exhibit directional distributed lasing, with emission guided through the crystalline lattice, producing highly directional and circularly polarized laser output. The laser action is attributed to resonant polarization modes of the BP lattice, characterized by angular dispersion and strong chiral selectivity. These findings establish BP monocrystals as viable platforms for integrated photonic systems and mirrorless lasing.
Results: In this work, we demonstrate the fabrication of stable, large-area monocrystalline blue phase (BP) photonic crystals with a precisely aligned (110) lattice and photonic stopbands positioned beyond the visible spectrum. Verification of a single-domain lattice via Kossel pattern analysis and reflection spectroscopy confirms the high structural order of the samples. Owing to the cubic symmetry of the BP lattice, the resulting photonic crystals display isotropic optical properties, enabling fast, polarization-independent modulation.
Electro-optical characterization further validates the performance of these monocrystalline BPs as efficient, high-speed phase modulators. Uniform phase shifts of up to π radians were achieved across all polarization states, with switching times in the sub-millisecond range—surpassing traditional liquid crystal technologies. These results position monocrystalline BPs as a promising platform for next-generation photonic applications requiring broadband, rapid, and polarization-independent optical control, including adaptive optics, beam steering, and holographic systems.
(2025-11-25)
