Xianguang Yang

The liquid-phase epitaxy (LPE) layer-by-layer method can be used to prepare metal-organic framework (MOF) materials suitable for nonlinear optical regulation due to its advantages of controllable thickness and smooth surface. In this study, Co-BTE MOF thin films were successfully synthesized by this technology, and their nonlinear control performance was studied by combining the spatial self-phase modulation method (SSPM). The results demonstrate that the Co-BTE MOF film has a significant nonlinear response with obvious third-order nonlinear optical effects observed. It was determined that the third-order nonlinear absorption coefficients of the Co-BTE MOF film were -0.03, 0.16, 0.33, and 0.04 cm/GW at wavelengths of 400, 532, 635, and 785 nm, respectively. To further investigate the nonlinear behavior of Co-BTE MOFs, the methods of SSPM and spatial cross-phase modulation (SXPM) were proposed to analyze their nonlinear regulation performance. Fortunately, the nonlinear properties of Co-BTE MOFs can be used to realize the functions of all-optical switches and photonic diodes, providing a reference for the development of nano-optoelectronic devices.

Fiber‐optic waveguides (FOWGs) are undergoing a transformative leap beyond their traditional role as passive light‐transmission channels. This evolution is fueled by the integration of novel functional materials—such as stimuli‐responsive hydrogels, aggregation‐induced emission (AIE) luminogens, and natural biomaterials—coupled with advanced fabrication techniques. These innovations enable a “material‐as‐function” paradigm, embedding capabilities like sensing, actuation, and computation directly into the waveguide structure. This Perspective explores how these intelligent FOWG‐based platforms are unlocking emerging applications in real‐time environmental and biomedical sensing, minimally invasive photomedicine, and intuitive human‐machine interfaces for robotics. Looking forward, we chart a developmental trajectory from materials to devices and systems, emphasizing the pivotal role of artificial intelligence in orchestrating this multifunctional integration. The convergence of material science, photonics, and AI is poised to transition FOWGs from simple optical pipes into adaptive, intelligent platforms that will underpin next‐generation healthcare, environmental monitoring, and interactive technologies.

Achieving efficient n-type doping in hexagonal boron nitride (hBN) remains a critical challenge for deep-UV optoelectronics. Here, we demonstrate voltage-controlled dual-band electroluminescence (EL) in In-doped hBN heterostructures epitaxially grown on p-GaN via magnetic sputtering. Precise In doping introduces mid-gap states enabling n-type conductivity (carrier density: 3.87 × 10¹⁸ cm^-3) and activates ultraviolet emission (332 nm, 378 nm) above 6 V bias in In-doped hBN. Simultaneously, the GaN region exhibits bias-dependent blue (447 nm, 14 V) emission with broad visible bands. First-principles calculations reveal that In substitution at B sites creates recombination centers, while unintentional defects in GaN drive yellow-blue transitions. The p-n heterojunction facilitates efficient carrier injection, enabling dynamic spectral tuning from UV to visible light. This work establishes a new paradigm for adaptive light sources in wide-bandgap semiconductors.

Fiber-structured ion sensors have gained traction in health monitoring and medical diagnostics owing to their structural flexibility, enhanced sensitivity, and suitability for integration into wearable devices. This study employed a simple and efficient solution-based process to fabricate nanofibers containing aggregation-induced emission (AIE) dyes. The resulting AIE nanofibers exhibited stable and intense fluorescence, nanosecond fluorescence lifetime, and low-loss light transport when functioning as active waveguides. Additionally, crossed nanofiber intersections exhibited diffraction-limited emission spots. The AIE nanofibers demonstrate efficient and io-specific fluorescence quenching in response to Ag⁺. These results support the development of sensing units capable of operating in liquid environments or in direct contact with skin or tissues, facilitating real-time monitoring of ion concentrations for personalized healthcare management.

Boron nitride (BN), as an emergent wide-bandgap material, is gaining considerable attention as a solid-state deep ultraviolet source and quantum emitter from the ultraviolet to the near-infrared spectral ranges. However, studies of the defect structure of BN and efforts at scalable BN emitters in photonic devices are limited. Controlling the BN doping is of particular interest in view of the light emission of defects. Here, it is demonstrated for the first time that doping amorphous BN (a-BN) with indium (In) shows luminescence spectra tuning from blue to red light, and only 765 nm (1.63 eV) light is dominant when more In content is introduced. The visible light emission is found to be the transition between the defect center of In_N (a substitutional In of nitrogen) and O_NV_B (a substitutional oxygen with an adjacent boron vacancy). While O_NV_B is identified experimentally in accordance with previous theoretical assumptions, and is optically accessible with a zero-phonon line (ZPL) of about 1.63 eV with increasing In proportion. Moreover, the heterogeneous integration of synthesized In-doped a-BN in silicon platforms is demonstrated by the realization of a 700-1000 nm broadband photodetector. These devices operate self-biased at room temperature and show a high photoresponsivity of ∼1.5 A/W (at 980 nm with -2 V bias), a quick response time of ∼90 μs, and a detectivity of 1.02 × 10⁹ cm·Hz^1/2/W. This work fundamentally contributes to establishing infrared detection by doping a-BN materials in heterojunctions with Si, at the forefront of infrared optoelectronics.

The omnipresence of polarized light on the surface of the earth, a result of atmospheric scattering, underscores the significance of detecting this light and extracting valuable information regarding the phase and polarization angle. In recent years, there has been a surge in research on polarization-sensitive photodetectors that utilize anisotropic two-dimensional (2D) materials. The essence of these 2D polarization-sensitive photodetectors is rooted in the anisotropic characteristics that arise from the asymmetric crystal lattice of the 2D materials in question. This anisotropy is manifested in both optical and electrical behaviors due to the asymmetrical nature of the crystal structure. This article systematically categorizes anisotropic 2D materials and offers an insightful overview of their crystal structures. It also introduces various optical and electrical characterization techniques designed to elucidate the anisotropic properties of these materials. The focus of the article then shifts to detailing the current state of research in the realm of anisotropic 2D material-based polarization-sensitive photodetectors. It provides a comprehensive description of the working principles behind polarization-sensitive photodetectors with different structural designs, shedding light on the underlying mechanisms that enable their polarization sensitivity. In conclusion, the article summarizes the findings of this review, highlighting the advancements and challenges in the field. Additionally, this review proposes several forward-looking recommendations to guide the future trajectory of research and development in the domain of 2D material-based polarization-sensitive photodetectors.

Enhanced by diverse color sorting techniques and deep learning, color routing at the nanoscale shows great potential in the image sensing field.

Optical biosensors based on micro/nanofibers are highly valuable for probing and monitoring liquid environments and bioactivity. Most current optical biosensors, however, are still based on glass, semiconductors, or metallic materials, which might not be fully suitable for biologically relevant environments. Here, we introduce biocompatible and flexible microfibers from lotus silk as microenvironmental monitors that exhibit waveguiding of intrinsic fluorescence as well as of coupled light. These features make single-filament monitors excellent building blocks for a variety of sensing functions, including pH probing and detection of bacterial activity. These results pave the way for the development of new and entirely eco-friendly, potentially multiplexed biosensing platforms.