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Multidimensional and large‐scale parallel manipulation of light, especially on‐demand tailoring of the working frequency and spatial phase front, is highly pursued in modern optics. Here, broadband tunable planar optics is demonstrated by electrically driving the nanohelix of photopatterned heliconical cholesterics. By preprogramming the initial orientation of the helixes using a dynamic‐mask photoalignment technique, spatial geometric phases can be arbitrarily encoded to the reflected light in a reconfigurable way. Due to the reversible electrically variant pitch of the heliconical superstructures, the reflective Bragg band can be precisely selected in the range from 380 to 1550 nm. In addition to wavelength selection and geometric phase modulation, spatial amplitude modulation and spin reversion can be further expected. This may offer a platform for full‐dimensional manipulation of light, including wavelength/frequency, phase, amplitude, time, and spin, thus upgrading optical information processing techniques. [ABSTRACT FROM AUTHOR]

Topological defects are vital for tailoring soft matter properties and inspiring remarkable applications. Arbitrary guiding and dynamic tuning of director distributions are highly pursued in defect engineering of liquid crystals. Till now, the orientation control of smectic defect walls remains a challenge. Here, photoalignment is adopted to preset the surface anchoring in order to guide smectic oily streaks. Flexible defect engineering such as deflecting, bending, and splaying is demonstrated. Based on their combination, more complicated defect arrays are realized in a predictable manner. After electric stimuli involved, new functions of tunability and rotatability are unlocked. This work brings new insights to soft matter architectures, and will upgrade the existing micromachines, nanoparticle manipulations and advanced photonic applications. [ABSTRACT FROM AUTHOR]

Optics, playing an ever‐important role in life, is developing toward miniaturization and integration. Particularly, the field programming of integrated optics will benefit its functionality and durability, thus is highly pursued. Here, through precisely controlling the space‐variant orientations of anisotropic liquid crystals (LCs), various graded‐index waveguides are demonstrated in a homogeneous medium. Straight/bending waveguides and ring resonators are fabricated via LC photopatterning. They exhibit pronounced polychromatic light‐guiding performance. Thanks to their intrinsic external‐stimuli responsivity, the thermal switchability and polarization tunability are verified. By selectively polymerizing, robust functional components and active connecting waveguides can be realized on the same chip. It provides a practical and universal solution to programmable integrated optics, and extends the applications of microstructured soft matter even in wearable photonics. [ABSTRACT FROM AUTHOR]

Terahertz (THz) band is expected to satisfy the ever‐increasing demand for high‐capacity wireless data transfer. Multifunctional photonic devices with compactness and low loss are highly pursued for future THz communications. Here, a strategy for planar THz photonics is proposed that enables free wavefront manipulation with submillimeter thin liquid crystal polymer (LCP) films. Such elements work on the spatial geometric phase modulation, which is accomplished by preprogramming the axis orientations of LCP. The LCP monomers follow the guidance of local photoalignment agent and are further polymerized under UV exposure at the existence of a doped photo‐initializer. Thanks to the high resolution and excellent flexibility of the photopatterning technique, THz elements with versatile functions can be realized. As examples, waveplates, polarization gratings, and lenses, which are suitable for the polarization control, beam deflecting, focusing, or collimating, are demonstrated. Due to the intrinsic flexibility of LCP films, an f‐tunable lens enabled by mechanically induced deformation is exhibited. Specific mode generators for vortices and Bessel beams are also presented, which can function as separate channels for the mode division multiplexing in THz communications. This work provides a robust platform for fabricating integrated, low‐loss, and tunable THz elements suitable for the advanced THz apparatuses. [ABSTRACT FROM AUTHOR]

Optical field control of laser beams is realized through photo-aligned liquid crystals. A dynamic micro-lithography system combined with a polarization-sensitive alignment agent is utilized to perform arbitrary fine liquid crystal alignment. Fork gratings are fabricated to generate high quality optical vortices. Forked polarization gratings with space-variant liquid crystal azimuthal orientations are proposed and corresponding optical vortices with arbitrary azimuthal and radial indices are demonstrated in high efficiency. Moreover, Airy masks for polarization selective Airy beam generation and polarization converters suitable for arbitrary vector beams are fabricated. This technology drastically enhances the capability of optical field control. [ABSTRACT FROM AUTHOR]

Azobenzene-containing polymers (azopolymers) are a kind of intensively explored fascinating photoresponsive materials, liquid crystalline (LC) azopolymers with excellent film-forming, ordered structure and self-repairing capability are endowed with enhanced photoisomerization and photoalignment characteristics capable of developing into photo-modulated smart surfaces. Here in this work, two azobenzene side-chain LC polynorbornenes of PNB-Azo-n with different DP of n = 50 and 100 have been well synthesized through ring-opening metathesis polymerization (ROMP). The polynorbornene backbone of less flexibility with larger spacing between adjacent azobenzene side groups endows stronger inhibition for H-aggregation and better photoresponsiveness. The high-DP azopolynorbornene of PNB-Azo-100 thin films well behave as command surface for the upper layer nematic LC molecules thanks to their better performance in photoisomerization and photoalignment, together with their good compatibility and dissolution-resistance to the nematic LC mixture of E7. Selectively optically readable LC graphic writings at normal size through various photomasks have been demonstrated, and higher grid resolution up to sub-ten micrometer with a digital micromirror device (DMD) based dynamic photopatterning system has been achieved. Therefore, such kind of LC azopolynorbornenes demonstrate promising applications in LC photoalignment system and photoresponsive devices for potential anti-forgery document security and smart card technology. Image 1 • Synthesis of LC polynorbornenes with side-chain azobenzene via ROMP (DP 50, 100). • Semi-rigid polynorbornene inhibiting H-aggregation and promoting photoresponse. • Photoaligned high-DP azopolymer thin films as command surface for LC E7 patterning. • High grid resolution up to sub-ten-micrometer from DMD based dynamic photopatterning. • LC photoalignment and photoresponsive systems promising for anti-forgery application. [ABSTRACT FROM AUTHOR]