Optically isotropic fast phase modulation in 3D blue phase photonic crystals

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.

本数据集包含蓝相光子晶体（Blue Phase photonic crystals）制备与电光表征实验方法的补充数据。
研究目标：制备大面积单晶晶格蓝相液晶结构，使其光子禁带位于可见光光谱之外，在保留立方晶格本征光学各向同性的同时，实现完全透明的工作状态。依托该平台，我们展示了一款偏振无关的相位调制器，其响应时间处于亚毫秒级，凸显了单晶晶蓝相在快速、透明可重构光子器件领域的应用潜力。
实验方法：采用自制的向列相主体材料（由氟化三联苯、联苯及环己基联苯组成），结合介晶单体与手性掺杂剂ISO(6OBA)₂，配制蓝相（Blue Phase, BP）前驱体混合液。通过精准调控掺杂剂浓度并使用弱锚定取向层，可重复获得晶格取向与尺寸可控的大尺寸单晶晶BPI(110)畴区，同时抑制竞争性的BPI(200)畴区。将混合液注入氧化铟锡（indium-tin-oxide, ITO）镀膜玻璃盒（盒厚3~5 μm），经热循环诱导蓝相形成，随后通过紫外照射实现聚合物稳定化。采用偏振光学显微镜、反射光谱学以及结合衍射模拟的科塞尔（Kossel）图案分析，对相行为与晶体学取向进行表征以提取晶格参数。电光性能通过马赫-曾德尔（Mach–Zehnder）干涉仪评估，以测量电压依赖的相位调制特性；同时利用宽带反射光谱监测光子禁带及其在可控辐照条件下的稳定性。
结果：本研究实现了毫米级稳定单晶晶蓝相光子晶体的定向激射，这是一项重要进展——此前仅在多晶样品中观察到随机激射现象。该结构展现出定向分布式激射特性，发射光通过晶体晶格传导，产生高度定向且圆偏振的激光输出。该激光效应归因于蓝相晶格的共振偏振模式，其特征为角色散与强手性选择性。本研究证实单晶晶蓝相可作为集成光子系统与无镜激射的可行平台。
结果：本工作制备了稳定的大面积单晶晶蓝相（Blue Phase, BP）光子晶体，其晶格精确对准(110)晶面，光子禁带位于可见光光谱之外。通过科塞尔图案分析与反射光谱学验证了单畴晶格的存在，证实样品具有高度结构有序性。得益于蓝相晶格的立方对称性，所得光子晶体展现出各向同性的光学特性，可实现快速、偏振无关的相位调制。电光表征进一步验证了此类单晶晶蓝相作为高效高速相位调制器的性能。在所有偏振态下均可实现高达π弧度的均匀相移，开关时间处于亚毫秒级，优于传统液晶技术。上述结果表明，单晶晶蓝相可作为下一代光子应用的极具潜力的平台，适用于需要宽带、快速且偏振无关光学控制的场景，包括自适应光学、光束转向与全息系统。