Planar optics offers a compact and versatile platform for manipulating multiple dimensions of light parameters and thus has attracted tremendous interest in high-density data storage, high-security information encryption, and holographic displays. It is still challenging to achieve active functionalities via dynamically operating light-matter interactions inside these planar optics. Here, a polymer-stabilized cholesteric liquid crystal (CLC) is adopted as a tunable one-dimensional chiral superstructure. The bandgap tends to change from a periodic helix to a gradient-pitch configuration under direct current (DC) voltage, and the reflection bandwidth varies from a narrow band of 40 nm to a broad band of 180 nm. Off-axis phase-only holograms of three primary colors are properly k-space engineered via a modified Gerchberg-Saxton algorithm, and recorded into the initial alignments of the CLC by photopatterning. By altering the applied DC voltage, the generated holography actively switches between a monochromatic and polychromatic image. Moreover, spin-selective Bragg-Berry phase encoding in photopatterned superstructures with opposite helicity allows distinct holograms (e.g., "weather sign" and "chameleon") to be independently generated and modulated. This work takes full advantage of soft chiral superstructures for on-demand light control and has great potential in dynamic holography, information encryption, and data storage.

We demonstrate an electrically tunable dual-mode metalens capable of polarization-sensitive focal control, combining high-resolution imaging and depth-sensing functionalities into a single compact device. By integrating hydrogenated amorphous silicon (a-Si:H) meta-atoms with a liquid crystal (LC) modulator, the proposed metasurface independently manipulates left- and right-circularly polarized (LCP/RCP) incident light, generating a rotating double-helix focal distribution for LCP and an extended depth-of-focus (DOF) for RCP illumination. The meta-atoms were rigorously optimized using propagation and geometric phases, enabling precise phase control and high transmittance at a wavelength of 635 nm. Experimental characterization confirmed near-diffraction-limited lateral and axial resolutions, closely aligning with theoretical predictions. The integrated LC cell facilitates milliseconds polarizationswitching between depth-sensitive double-helix and high-resolution DOF imaging modes. We further verified depth-extraction capabilities by analyzing rotation angles from dual-image focal spots under mixed-polarization illumination. Depth-resolved imaging of a rubber-tree leaf, a skeletal-muscle cross-section, and a live planarian retrieved color-coded depths, demonstrating the effectiveness on complex biological tissues. This polarization-driven, electrically tunable metalens thus provides a versatile and effective optical platform suitable for advanced applications in biomedical imaging, three-dimensional sensing, adaptive optics, and compact imaging systems.

Urban architects increasingly seek solar windows that deliver both energy generation and aesthetic value. However, existing color-engineering strategies rely on absorptive metal layers or lack control over the achievable colors. Here, we present a modelling-guided inverse design strategy that integrates an all-dielectric (ZnS/MgF₂) multilayer into semitransparent perovskite photovoltaics, enabling user-defined colors with minimal spectral loss. Leveraging an active learning algorithm, we mapped the attainable color gamut for ZnS/MgF₂-coated devices with distinct perovskite absorber thicknesses and average visible transmittance (AVT) values. As a representative case, a device with a 110 nm-thick absorber on glass or polyethylene terephthalate (PET), initially exhibiting a reddish-brown tint, was transformed into vivid cyan using a 600 nm-thick all-dielectric multilayer. This tuning retained high AVT—6.5% on glass and 5.3% on PET—while enhancing power conversion efficiency by 20.9% and 10.4%, respectively. Real-world imaging confirmed enhanced aesthetics with see-through visibility, underscoring the practical potential of the inverse-design framework. Moreover, this approach is readily transferable to other thin film photovoltaics, providing a versatile route toward color customizable, transmittance-tunable, and high-efficiency solar windows for buildings, vehicles, and wearable electronics.

Programmable metasurfaces have shown exceptional potentials in wireless communications due to their capability to manipulate electromagnetic (EM) waves dynamically and flexibly. However, the large-scale application and flexible deployment of programmable metasurfaces still face challenges of high communication capacity requirements and stringent energy constraints. Here, we report an ambient-energy-driven space-time-coding metasurface to address these issues. On one hand, the metasurface can achieve efficient space-frequency-division multiplexing manipulations by dynamically controlling multiple frequencies and the spatial propagation directions of reflection EM waves. On the other hand, the shared-aperture ambient solar energy harvesting capability and low power consumption characteristic of the metasurface enable it to be self-powered without relying on any external power supply. To demonstrate these remarkable features, a four-channel wireless communication system prototype is built using the programmable metasurface. Experimental results confirm that four distinct images can be transmitted to four user terminals simultaneously, independently, and in real time with remarkably low energy consumption per bit. Such innovative metasurface provides a simple and effective approach for integrating ambient energy harvesting, multi-dimensional microwave manipulation, and direct information modulation on a single physical platform, which will advance the wireless communications in cost-effectiveness, enhanced capacity, energy efficiency, and environmental friendliness.

Thin-film lithium niobate has become a promising platform for integrated photonics due to its outstanding electro-optic and nonlinear properties. However, the development of on-chip tunable lasers, which is essential for a plethora of applications ranging from optical communications and sensing to metrology and quantum technology, remains limited. Current solutions fall short in either wavelength tuning range or precision, and frequently relies on complex control strategy. Here, we demonstrate an integrated electro-optically tunable narrow-linewidth III-V laser, achieving a tuning range of ~51.8 nm, an intrinsic linewidth of ~1.21 MHz, and high tuning precision of ~0.03 nm. Specifically, our external cavity uniquely combines highly reflective Sagnac mirrors and a series of unbalanced interferometers which together offer a spectral response in favor of single-longitudinal-mode narrow-linewidth lasing operation, evidenced by not only experimental demonstration but also insightful theoretical analysis.

Integrating functional materials, photonic structures and circuits in an optical fiber platform provides opportunities for a range of novel applications. Recently, Yuan TT et al presents a comprehensive review on the development of in-fiber photonic integrated devices and systems, including historic background, methods of integration, structures and materials, functionalities and performances, as well as applications in sensing, communications, signal manipulation and processing, medical diagnosis and treatment. The review also includes insightful analysis and discussion of future research directions.