Light‐Activated Liquid Crystalline Hierarchical Architecture Toward Photonics

Abstract

remarkable structure results in a helical-variant dielectric tensor, thus contributing to a natural 1D photonic crystal. [7] It is endowed with a broadband Bragg reflection with a unique circular-polarization selectivity. Blue phase (BP) is another fantastic phase with 3D stacked lattice ( Figure 1D). [8] Such an elegant state-of-matter is energetically preferred in a high chirality system, commonly existing in a narrow temperature range of less than 1 K, between the cholesteric and isotropic phases. It has an exotic arrangement characteristic of LCs, which twists around two helical axes forming cylinders including hierarchically twisted molecular architectures. Such double twisted cylinders are impossible to tile the whole 3D space, which leads to inevitable disclinations and results in frustrated structures.Self-organization is an intrinsic ability of LC molecules. However, the precise control and generation of large-area desirable hierarchical superstructures require state-of-the-art techniques that usually combine the "top-down" microfabrication with the "bottom-up" self-assembly. Here, we review various hierarchical architectures in SLCs, CLCs, and BPLCs, especially recent progresses in light-activated LC hierarchical superstructures, as well as their optics and photonics applications in optics and photonics. In this review, we will see the controllable spatial smectic layer curving via 2D anchoring confinement, 3D topographic confinement, and external field guidance, with which the domain size, shape, orientation, and lattice symmetry of focal conic domain (FCD) arrays are well manipulated. The control of helix direction or fluctuation of CLC layers and the growth of unique fingerprint textures including spiral and wave-like continuous gratings are presented. The 3D manipulation of BPLC hierarchical architecture is accomplished photoalignment and various light-driven azobenzene molecular motors. The construction of these unique hierarchical superstructures brings new opportunities to the design of novel optic and photonic devices. Corresponding applications, including traditional microlens array, beam steering, and more advanced specific optical field generation and LC lasers are comprehensively reviewed as well.

Biomimetic design of iridescent insect cuticles with tailored, self-organized cholesteric patterns

“…The twisted CLC patterns issued from the present design pave the way to many possibilities of practical uses. They may inspire future applications in optics, in the field of non-specular properties such as deflection and lensing in geometric phase planar optics [66][67][68] . The phase of light that is Bragg-reflected off the helical structure can be controlled over 0-2π depending on the spatial phase of the helical structure 66 .…”

Stimulated Scattering of Surface Plasmon Polaritons in a Plasmonic Waveguide with a Smectic A Liquid Crystalline Core

“…Different types of NLC plasmonic waveguides have been proposed and investigated theoretically [36][37][38]. Recently, SmALCs attracted attention due to their layered structure and reconfigurable layer curvature [39]. The possibility of the dynamic variation of smectic layer configuration by external fields is intensively studied [39].…”

“…Recently, SmALCs attracted attention due to their layered structure and reconfigurable layer curvature [39]. The possibility of the dynamic variation of smectic layer configuration by external fields is intensively studied [39]. We investigated theoretically SLS in the optical slab waveguide with the SmALC core where the third-order optical nonlinearity mechanism was related to the smectic layer dynamic grating created by the interfering waveguide modes [27].…”

Nonlinear Optical Phenomena in a Silicon-Smectic A Liquid Crystal (SALC) Waveguide

“…The scattering losses in smectic waveguides caused by dynamic distortions of the smectic layer planes are several orders of magnitude lower than in nematic waveguides [2,24], and SLCs may be used in nonlinear optical applications [2]. Recently, the reconfigurable smectic layer curvature has been studied [25]. The using of the external electric field to create the dynamic variations of the smectic layer configuration attracted a wide interest [25].…”

“…Recently, the reconfigurable smectic layer curvature has been studied [25]. The using of the external electric field to create the dynamic variations of the smectic layer configuration attracted a wide interest [25]. The different types of the periodic focal conic domain (FCD) arrays with the domain size, shape, orientation, and lattice symmetry controlled by external fields can be obtained [25].…”