Exceptional points (EPs) in non-Hermitian systems can produce nonlinear responses to weak perturbations, but maintaining these responses at a stable operating frequency remains challenging. Here, we develop a hyperbolic photonic metacrystal that combines dispersion and loss engineering. By exploiting the opposite angular dispersions of the hyperbolic and dielectric layers, we achieve first-order phase compensation that suppresses angular variations in the accumulated optical phase and keeps the localized resonances nearly unchanged with incident angle. We first consider a parity-time (PT)-symmetric system with balanced effective gain and loss, where a Hamiltonian EP coincides with a scattering-matrix (S-matrix) EP. Although this operating point exhibits square-root scattering-eigenvalue splitting, refractive-index perturbations also shift the Hamiltonian eigenfrequencies, limiting the stability of the operating frequency. By breaking the effective gain-loss balance, we obtain a PT-asymmetric state in which the squared coupling strength equals the product of effective gain and loss. Under this condition, a bound-state-in-the-continuum (BIC)-associated real-frequency solution emerges, and the S-matrix remains at an EP while the effective Hamiltonian no longer exhibits an EP. The scattering eigenvalue splitting therefore retains its square-root dependence on refractive-index perturbations, while the resonance-frequency drift is substantially reduced. Together with hyperbolic phase compensation, this response is maintained over incident angles from 0° to 60°, offering a route to EP-based sensing that combines angular robustness with spectral stability without sacrificing the square-root scattering response.

We discover that a standard Fourier transformation intrinsically imparts a parity-dependent phase shift to optical vortices, yielding a phase difference of π between modes carrying odd and even topological charges. This phase shift, however, is not directly observable from the intensity profile of the transformed beam. To render it measurable, we develop a spin-selective Fourier transformer by co-designing propagation-induced dynamic phase and Pancharatnam-Berry geometric phase in a pair of hybrid-lenses. This device converts the parity-dependent phase shift into orthogonal polarization states via spin-orbit interaction, enabling non-destructive separation of both individual and superimposed orbital angular momentum (OAM) modes without the need for an interferometer. Our work establishes Fourier transformation as a new mechanism for parity-resolved vortex manipulation, offering an integrable platform for high-dimensional photonic applications.

Compared with conventional intensity imaging, complex optical field imaging enables the recovery of both amplitude and phase information of the optical field, and has become an important tool in label-free microscopy, surface metrology, and crystal characterization. However, because conventional detectors can only measure intensity and cannot directly record phase, complex field reconstruction is an ill-posed inverse problem that heavily relies on physical constraints and computational priors. Optical field modulation offers an effective solution by imposing known, controllable modulations into the illumination, propagation, reference, or detection path, improving the observability and recoverability of phase information. Optical field modulation increases the measurement diversity and improves the solvability of the inverse problem, reducing reconstruction ambiguity and improving robustness to noise and missing data. This review establishes a unified framework that classifies optical-field modulation according to the measurement mechanism and modulation location, and compares different strategies in terms of information diversity, identifiability, acquisition efficiency, calibration burden, and dynamic adaptability.

Quantum theory departs from classical physics in its treatment of correlations, most prominently through the phenomena of contextuality and nonlocality. Once regarded primarily as foundational curiosities, these effects are now understood as key operational resources for quantum computation, communication, and simulation. Although traditionally investigated in distinct settings, recent theoretical and experimental advances have revealed deep conceptual, mathematical, and operational connections between them. This review presents a unified perspective on these developments based on sheaf-theoretic and graph-theoretic frameworks, which provide theory-independent characterizations of statistical correlations. These approaches clarify the structural relationship between contextuality and nonlocality, facilitate the formulation of experimentally testable inequalities, and guide implementations in realistic physical platforms, with particular emphasis on photonic experiments using structured light and orbital-angular-momentum encoding for high-dimensional quantum states. By bridging abstract theoretical structures and concrete experimental realizations, this review sheds light on the nonclassical foundations of quantum correlations and their emerging role in quantum technologies.

Conventional complementary metal-oxide-semiconductor (CMOS) image sensors with Bayer color filter arrays face limitations in low-illumination color imaging. Color router (CR) aims to achieve absorption-loss-free spectral separation, providing an efficient way to sort and guide different color lights to the corresponding pixels. However, applying CR to imaging chips requires consideration of different incidence conditions and processing difficulties. In this study, we propose and fabricate a polarization-insensitive “red, green and blue + near-infrared (NIR)” CR based on a metasurface, operating within the wavelength range of 400-1,100 nm and exhibiting high light energy utilization efficiency. The structural parameters are optimized through an inverse design method. The device is fabricated by silicon-compatible processes, offering the advantage of high integration. Experimental results demonstrate that the measured energy utilization efficiency reaches over 90%, and the measured average correlation coefficient of spectral curves under different polarizations reaches 0.98. This device can efficiently route visible to NIR light, providing a novel approach for integrating metasurfaces into CMOS image sensors to enhance high-performance color imaging systems.

Metasurfaces, as a key platform for flat optics, enable advanced manipulation of light by harnessing rich local and nonlocal resonant modes at subwavelength-structured interfaces. Distinct from conventional local metasurfaces that primarily modulate optical wavefronts over broad spectral ranges, nonlocal metasurfaces based on collective resonances provide enhanced spectral and momentum selectivity together with strengthened light–matter interaction. This review surveys recent advances in optical-field information manipulation enabled by nonlocal metasurfaces, where “information manipulation” denotes the high-dimensional control of amplitude, phase, and polarization across spectral, temporal, spatial, and momentum domains, with a particular focus on integrating local and nonlocal resonances to enhance device performance and functionality. We first introduce the fundamental characteristics of nonlocal resonances and summarize representative progress in real- and momentum-space light control within passive nonlocal metasurfaces. We also discuss recent advances in active nonlocal metasurfaces, including applications in nonlinear harmonic generation, quantum-state control, and spatial information lasers. Finally, we highlight emerging trends in on-chip and tunable nonlocal metasurfaces and outline key challenges and future research directions for this rapidly evolving field.

Phase-shifting profilometry (PSP), as a high-precision and low-cost three-dimensional (3D) profile measurement technique, has been extensively applied in diverse fields. By introducing the compressive sensing paradigm, compressive phase-shifting fringe projection profilometry (CPSFPP) provides an effective solution for high-speed dynamic object acquisition. Nevertheless, achieving high-fidelity dynamic profile reconstruction from compressed measurements remains a considerable challenge, owing to the inherent information loss in compressive sampling and limitations in computational reconstruction, especially under high compression ratios. To address this issue, we propose a physics-informed neural network (PINN)-based computational imaging framework for high-fidelity CPSFPP, named PINN-CPSFPP. This method integrates the physical model constraints with neural network learning to guarantee high-fidelity reconstruction even at high compression ratios. We perform numerical simulations to verify the reconstruction accuracy of PINN-CPSFPP under different compression ratios and experimentally validate the method by measuring translational, rotational, and deformed objects. The results demonstrate that the measurement speed is increased by nine times compared with conventional PSP. Benefiting from its robust 3D imaging performance, PINN-CPSFPP serves as a high-fidelity metrological tool for high-speed 3D scenarios and exhibits promising application prospects in a wide range of basic and applied disciplines.

Metasurfaces composed of subwavelength-scale artificial meta-atoms have emerged as a powerful platform for manipulating light. By enabling strong light-matter interactions within ultrathin planar geometries, metasurfaces have opened new avenues for highly integrated photonic devices. Lithium niobate (LiNbO₃) is considered one of the most promising multifunctional integrated photonic platforms due to its outstanding properties, such as a large second-order nonlinear susceptibility, a broad transparency window, and a strong electro-optic (EO) effect. In recent years, integrated photonic devices based on lithium-niobate-on-insulator platforms have experienced rapid development. This review summarizes recent advances in LiNbO₃ metasurfaces, providing a comprehensive overview of their demonstrated applications in nonlinear frequency conversion, wavefront and phase modulation, and dynamic EO modulation. By systematically introducing the interplay between the intrinsic material properties of LiNbO₃ and the structural design principles of metasurfaces, this review offers a coherent framework for understanding their nonlinear and active optical functionalities, and serves as a valuable reference for the design and implementation of nonlinear and actively tunable micro- and nano-photonic devices.

Sculpted light, or optical fields with specifically engineered spatial, modal, and vectorial degrees of freedom, has developed as a powerful paradigm for optical sensing, allowing for improved and multidimensional light-matter interactions that extend beyond typical Gaussian illumination. By exploiting degrees of freedom such as orbital and spin angular momentum, spatial mode, polarization, and topology, sculpted light fields provide additional channels through which physical parameters can be mapped onto measurable optical transformations. Rather than merely enhancing sensitivity, sculpted light expands the dimensionality of optical sensing. Recent studies show how tailored optical fields provide additional sensing channels for encoding physical information, enabling precise measurement of parameters such as strain, temperature, position, velocity, refractive index, and structural asymmetry. This article provides a unified viewpoint on the generation and sensing applications of sculpted light, including both fiber-based techniques that take advantage of specialty fibers supporting higher-order modes and free-space techniques. As photonic integration, quantum-state engineering, and machine learning converge with advanced beam shaping technologies, sculpted light is poised to become a foundational strategy for next-generation optical sensing.

Knots and links play a fundamental role across a wide range of physical fields, from classical to quantum physics. In optics, structured light fields with multiple controllable degrees of freedom provide a versatile experimental platform for investigating topological properties. Knot theory underpins the topological control of high-dimensional structured light, thereby giving rise to fundamental physical effects and applications. Furthermore, topologically structured light has attracted significant attention for light-matter interaction. Here we review the recent advances in topologically structured light from the perspective of knot theory. Starting from the basics of knots and related braids, we introduce the generation and manipulation of topologically structured light from the purely spatial domain across to the spatiotemporal domain. Moreover, we demonstrate that the particle-like structured light, such as photonic skyrmions and hopfions, can host the topologies of high dimensional space, followed by brief discussions on potential applications as well as an outlook and future trends and challenges in this field.

Spatiotemporal optical vortices (STOVs) possess helical phase singularities distributed jointly in space and time, enabling light to carry transverse orbital angular momentum and offering a fundamentally new degree of freedom for structured light. However, the precise detection of STOVs with fractional topological charges remains highly challenging, as conventional interferometric and diffraction-based techniques suffer from limited resolution and experimental complexity. Here we demonstrate a scattering-assisted detection scheme that enables ultra-high-precision measurement of STOVs with fractional topological charges. By exploiting the sensitivity of random scattering media to the spatiotemporal phase structure of broadband optical fields, we establish a robust mapping between scattered intensity patterns and fractional STOV states. This approach achieves reliable discrimination of fractional topological charges with step sizes down to 0.01, significantly surpassing the resolution of existing methods. Furthermore, we leverage this capability to realize a multi-level free-space optical communication scheme encoded by fractional STOV states, demonstrating enhanced channel capacity within a compact experimental configuration. This work introduces scattering media as a powerful platform for probing spatiotemporal phase singularities, and opens new opportunities for high-dimensional spatiotemporal photonics and optical communications.

Non-diffracting beams are typically confined to a limited set of specific profiles. Existing methods for diversifying these beams face challenges in achieving arbitrarily complex intensity distributions. In this paper, we present a phase engineering approach based on local spatial frequency mapping to construct novel non-diffracting beams. The proposed method facilitates the creation of customized intensity profiles by tailoring and splicing phase modulations in the Fourier domain, enabling the generation of intricate non-diffracting beams, such as those with a Tai Chi shape. We experimentally demonstrate the robust propagation invariance and self-healing capabilities of these novel non-diffracting beams. This approach provides a versatile means for designing structured non-diffracting fields, with potential applications in areas such as precision laser machining, optical trapping, free-space communication, and structured-light imaging.

Rare-earth-doped upconversion nanocrystals (UCNCs), with unique anti-Stokes emission, have been extensively explored, while their performances are hindered by the restriction of parity-forbidden 4f-4f transitions, making their emission difficult to control and resulting in low quantum yields. Current research primarily relies on modifying dopant types and concentrations, matrix composition, particle size, core-shell structures, and surface functional groups, to tune the absorption and emission transitions of 4f electrons. While these methods can effectively adjust emission spectra, reduce defects, and enhance luminescence efficiency, they cannot fundamentally regulate the 4f electron transition process, especially with respect to studying the intrinsic luminescence kinetics of rare earth ions. Therefore, a fundamental understanding of the transition behavior of 4f electrons and the ability to intrinsically control their absorption and emission processes are crucial. By manipulating the local optical field around UCNCs, micro-nano structures offer a powerful means to control their upconversion luminescence, making them an important tool for developing efficient optoelectronic devices for display, lighting, and conversion applications. In this review, we comprehensively expound on the optical engineering for UC luminescence control through micro/nano-optical structures. By utilizing structures such as plasmonic antennas, dielectric superstructures, high Q microcavities, and programmable wavefront shapers, precise control over the interaction between light and matter is achieved at multiple spatial scales. Moreover, we systematically analyze how such structures enhance local excitation fields, amplify spontaneous emission, and direct photon extraction, thereby transcending the inherent limitations of rare-earth emitters. By bridging advances in materials chemistry with nanophotonics design principles, this approach unlocks unprecedented control over UC efficiency, spectral purity, and polarization properties.

Structured light fields are engineered through precise control of their amplitude, phase, polarization, and spatiotemporal properties, which are extensively studied for both scientific and applied purposes, and can offer novel pathways for information processing, quantum communication, and precision measurement. Although the linear manipulation of structured light is already very mature with the help of liquid crystal devices and planar optical elements, nonlinear manipulation remains nascent, despite demonstrating unique potential for critical functionalities such as optical field information exchange. Hence, critical challenges now lie in harnessing nonlinear interactions, between light fields themselves and between light and matter, to achieve on-demand multidimensional control of target optical fields, particularly for spatial modes of light. The advancing nonlinear optics theory, guided by structured light, reveals novel physical phenomena in various nonlinear interactions, and promotes the development of novel applications based on nonlinear light field control technologies. Accordingly, this review systematically summarizes recent advances across key areas, including the nonlinear manipulation of spatial structured light fields, optical information transfer, full-dimensional manipulation theory, field modulation and nonlinear topological frontiers, and three-dimensional (3D) light field manipulation theory, thereby providing a comprehensive perspective on the current state and the emerging trends in this rapidly evolving field.

The development of surface-enhanced Raman scattering (SERS) technology is critically reliant on the effective modulation of the electromagnetic mechanism and chemical mechanism. In this paper, we conduct a systematic review of the recent advancements in the modulation of SERS by multi-physical fields (light field, magnetic field, and electric field) and their cooperative modulation. Light field modulation enhances the intensity and area of hotspots by optimizing the matching between the local surface plasmon resonance of nanostructures and the parameters of incident light (wavelength, polarization, and pulse). Moreover, the photo-induced plasmonic thermal effect dynamically regulates the phase transition between the nanogap and the material, achieving the synergistic enhancement of SERS. Magnetic field modulation capitalizes on the magnetic induction of magnetic materials and the magnetic resonance behavior of non-magnetic structures. It enables an external magnetic field to control the aggregation and spatial organization of nanoparticles, thereby generating high-density hotspots and enhancing the detection sensitivity and selectivity. Electric field modulation can adjust the band structure, carrier density, and molecular orientation of the substrate through an external electric field or the spontaneous electric field of functional materials (such as piezoelectric, triboelectric, thermoelectric, and pyroelectric materials), thus enhancing the charge transfer efficiency and the local electromagnetic field strength. The multi-field cooperative modulation strategy overcomes the static limitations of traditional SERS substrates and further provides a crucial theoretical and technical approach for realizing a high-performance, intelligent, and reconfigurable SERS sensing platform.

Twisted photonic lattices have recently emerged as a promising platform for opto-twistronics, enabling the exploration of moiré-induced photonic phenomena. Despite significant progress, the implications of non-Hermitian effects within these systems remain largely unexplored. In this work, we theoretically propose and experimentally demonstrate a non-Hermitian twisted photonic lattice with dynamically tunable gain-loss modulation, realized in a four-level atomic medium through the twisted superposition of two stripe fields. By adjusting the frequency detuning, a local flat band is introduced into the photonic band structure, leading to the directional localization of light in momentum space. The degree of localization can be further controlled by varying the laser power, while the direction of localization is reconfigured in real time by tuning the twist angle. Our work uncovers an intriguing interplay between non-Hermitian band reconstruction and geometric twisting by means of reconfigurable photonic lattice, and it provides a versatile platform for studying light manipulation in twisted configurations.

Optical vortices, characterized by their central singularities and spiral phase wavefront, have gained widespread attention in light manipulation and diverse applications. With their topological order being extended from integer to fraction, more unique properties have sprung out, such as continuous topological charges, fractional spiral-phase, expanded orbital angular momentum spectrum, and slit openings. These features have facilitated applications in areas such as optical tweezers, direction-selective edge enhancement imaging, robust rotational Doppler metrology, free-space communication, displacement sensing, and high-dimensional quantum entanglement. In recent years, advances in metasurface-based optical control, spatiotemporal pulse shaping, holographic imaging, and deep learning have spurred rapid innovation in the modeling, generation, and measurement of fractional vortex beams. This review begins with the fundamental theory of fractional vortex beams and surveys the latest developments in this rapidly evolving field. The scope of research has also expanded beyond optical vortices to include acoustic vortices. The growing interest in fractional vortex beams, coupled with ongoing technological innovations, is expected to pave the way for further advancements in this promising area of research.

Topology, a cornerstone of modern condensed matter physics, has in the past decade played a crucial role in diverse wave systems. As a powerful wave system, light can be sculpted into an even richer variety of topological structures, including vortices, skyrmions, Möbius strips, etc., leading to advanced photonic technologies from optical trapping to imaging, across quantum and classical regimes. A recent breakthrough demonstrated that topologically structured water waves can manipulate particles with intricate spin-orbital motion, and similar principles have enabled topological control in acoustofluidics, opening new insights in wave-matter interactions. Therefore, we argue that topological light waves possess an analogous potential, offering a route beyond the scalar-field limitations of conventional optical tweezers and establishing a new paradigm of multidimensional, vectorial control over matter. This article starts with brief introductions to optical tweezer technologies and topological light waves, then focuses on their emerging combination: particle trapping and sorting. It follows with perspectives on how topologies can couple to new degrees of freedom for manipulating complex particle motions previously inaccessible, and finally discusses potential applications.