Jianping Ding

Optical bimerons are topologically protected vector textures promising for communication, sensing, and information encoding. However, their generation traditionally relies on symmetric light fields, leaving asymmetric topological states largely unexplored. In this Letter, we experimentally generate anti-bimerons by superposing same-order asymmetric Laguerre–Gaussian (aLG) beams with conjugate complex shifts. The spatial symmetry breaking induced by these complex shifts facilitates the flexible construction of bimeron textures across various polarization bases. Furthermore, the identical Gouy phase between the superposed modes ensures topological stability during propagation. We elucidate how the asymmetry parameter modulates these robust structures during free-space propagation. This work enriches the paradigms of optical quasiparticle generation and provides a framework for leveraging light field asymmetry in topological information carriers.

The development of singular optics and vortex beams has facilitated numerous novel optical applications, with optical sensing being one prominent direction. By leveraging the rotational energy flow properties of vortex beams, rotational Doppler effect-based sensing for rotating objects has achieved significant progress. However, due to fundamental constraints of orbital angular momentum (OAM) and interferometry-based experimental methods, rotational Doppler sensing typically requires stringent axial alignment (single-point or multi-point) in practical scenarios, which limits their applicability. To address these limitations, this study focuses on developing rotating metrology utilizing singularities inherently associated with vortex phases, akin to the recently developed singularity ruler employing intrinsic/extrinsic modification of OAM density. In this work, we propose a sensing technique termed the “Optical Singularity Protractor (OSinP)”, which utilizes the angular velocity of singularities to reflect the rotational speed of optical fields. To extend the stable singularity ruler to dynamic rotation sensing, we developed a real-time neuromorphic singularity perception system capable of acquiring microsecond-level-resolution time-series data regarding singularity positions and movement directions, thereby enabling the sensing of optical field rotation velocity. Furthermore, we challenged the OSinP system with practical constraints, notably off-axis rotation and non-steady-state velocity, to verify its robust operational capabilities. This singularity sensing technique distinguishes itself from traditional rotation sensing by introducing neuromorphic computing into topological structured light and holds promise for neuromorphic applications in fields with stringent energy-efficiency requirements, such as astronomical metrology and embodied intelligence.

The orbital angular momentum (OAM) of light, arising from helical phase structure, has attracted great interest due to its wide applicability. The orthogonality among different OAM modes and their potentially unbounded dimensionality make OAM a powerful resource for constructing high-dimensional Hilbert spaces. Consequently, flexible and precise control over the OAM spectra is of great importance in both classical and quantum optics. Several techniques have been developed for the on-demand generation of arbitrary OAM spectra, including OAM combs. However, most of the input beams are confined to a Gaussian-like fundamental mode with a uniform azimuthal intensity distribution. In this work, we introduce a novel approach that efficiently shapes the OAM spectrum using pure phase modulation, applicable not only to the input Gaussian beam but also to input beams with azimuthally inhomogeneous intensity profiles. Our approach is experimentally demonstrated by converting an input Gaussian beam and various azimuthally structured beams into desired OAM combs and arbitrary OAM spectra. Our results not only expand the toolkit for the highly efficient generation of OAM combs but also provide a straightforward and effective means to control the OAM spectrum for non-uniform input optical fields.

Structured light undergoes severe distortion when propagating through complex media such as turbulent atmospheres and biological tissues, which hinders its practical deployment. Here, we propose a tailored search paradigm based on spatial‐mode‐fitted physics‐informed neural network (PINN) to retrieve structured light fields robust to such distortions in designated complex media. Different from conventional pixel‐based methods, our approach represents the optical field as a superposition of orthogonal Laguerre–Gaussian modes, which substantially reduces dimensionality and computational cost. The proposed physics‐driven and label‐free PINN incorporates wave propagation laws into the loss function, enabling the identification of light fields whose mode compositions remain invariant after transmission through disordered media. Experimental results demonstrate that the obtained robust light fields achieve an intensity structural similarity index measure (SSIM) above 0.8 and a negative Pearson correlation coefficient (NPCC) of the mode power spectrum below 0.1 in turbulent media, a performance nearly comparable to that in free‐space propagation. By customizing the loss function, this framework can also generate light fields that meet practical requirements such as a reduced number of constituent modes. This efficient and versatile strategy opens up new avenues for the deployment of robust structured light in real‐world scattering environments.

Coordinated manipulation of light field propagation is critically important and profoundly challenging for both fundamental research in optics and the expansion of its applications. Achieving independent spatial control over the properties of light—amplitude, phase, and polarization—lies at the core of this challenge. Here, we propose a vectorial synthesis scheme based on structured focal lines generated by a freeform phase mask to simultaneously tailor their spatial distributions. By strategically engineering the parameters of a freeform phase mask, we construct a pair of structured focal lines carrying customized phase profiles and mutually orthogonal polarizations. The coherent superposition of these two orthogonally polarized focal lines, serving as the basis beams, enables the generation of vector vortex beams with arbitrarily designable polarization states on the Poincaré sphere. Both numerical simulations and experimental demonstrations confirm that our method facilitates independent and effective manipulation of the amplitude, phase, and polarization along the prescribed two-dimensional or three-dimensional focal trajectories of these so-called freeform vector vortex beams (FVVBs). This work offers a flexible new approach for the regulation of multidimensional light fields.

Orbital angular momentum (OAM) holography exploits an unbounded set of orthogonal OAM states, in principle offering high information capacity for data storage and optical encryption. However, diffraction-induced degradation away from the focal plane restricts conventional OAM holography to a shallow depth of field, so high-fidelity reconstruction is achieved only near focus. Here, we demonstrate a propagation-stable OAM holography scheme based on angular-spectrum engineering. A specially designed annular mask constrains the output wavevectors to a conical geometry on the Ewald sphere, extending the usable depth of field from 0.8 cm (conventional OAM holography) to ∼40 cm. Within this reconfigurable framework, we prescribe an axially varying OAM modulation m ( z ) to enable stepwise longitudinal decoding of distinct images. We further demonstrate two-parameter addressing, in which multiplexed patterns are retrieved by a key pair consisting of the incident OAM state l _in and the selected axial segment, and the intended pattern is recovered only for the matching pair. Experimentally, the correctly addressed reconstructions achieve a structural similarity index measure (SSIM) exceeding 0.94 relative to the target patterns. These results establish a non-diffracting, reconfigurable OAM holography platform that offers a tunable depth of field and axial selectivity, with potential applications in optical encryption, displays, and high-capacity data storage.

Structured light has become a pivotal tool for optical manipulation, advancing applications from biology to micro-engineering. However, conventional orbital angular momentum (OAM) vortex beams are limited to unidirectional particle rotation in transverse planes, leaving longitudinal control largely undeveloped. Here, we introduce a longitudinally tunable OAM vortex beam (LTOVB) that enables versatile particle dynamics along the optical axis—including stationary trapping, speed modulation, and bidirectional rotation—while maintaining a constant orbital radius. Using vector diffraction modeling and experimental validation, we demonstrate programmable particle manipulation across sequentially tuned OAM segments under tight focusing.

Structured beams endowed with topological charges and singularities show great potential for both classical and quantum information encoding. While manipulation of topological charges is well-established, information carriers based on topological invariants governing singularity evolution—optical links and knots—remain underexplored. The fundamental limitation lies in detection bandwidth: resolving singularities behaving like optical darkness through conventional intensity localization demands prohibitive exposure times, thereby constraining the transmission rates. To address this issue, we introduce a neuromorphic approach—Logarithmic Intensity Gradient Handling Technology for Event-based Links-and-knots Formation (LightELF)—which enables microsecond-level asynchronous spatial readout of sparse singularities. By fusing logarithmic gradient sampling with the superoscillating nature of singularities, LightELF reconstructs links and knots without post-processing while achieving orders-of-magnitude data reduction. Moreover, we demonstrate a topological binary signal processing chain integrating a high-throughput transmitter with our neuromorphic detector. This work establishes optical links and knots as viable information carriers, pioneering event sensing in topological photonics and providing a neuromorphic signal framework for optical information processing.

Radially self-accelerating beams (RSABs), owing to their rotating propagation and orbital angular momentum (OAM) properties, have found applications in optical micromanipulation and optical metrology. However, conventional RSABs exhibit fixed propagation behaviors, and existing shaping approaches often lack compatibility, restricting their applicability in complex real-world scenarios. In this work, we propose an angular-spectrum engineering approach based on Fourier optics, enabling the design and control of multi-degree-of-freedom RSABs (Multi-DoF RSABs) with programmable angular velocity, longitudinal intensity, three-dimensional trajectory, and OAM. Experimental results demonstrate independent adjustment of these four degrees of freedom, in agreement with theoretical predictions. This work provides a flexible framework for designing RSABs and highlights their potential for applications in optical manipulation and microfabrication.

Radial self‐accelerating beams (RSABs) have attracted significant interest owing to their distinctive propagation‐dependent self‐rotation, petal‐like intensity profiles, and considerable application potential. Conventional methods for generating RSABs, however—such as those relying on Bessel beam superposition—suffer from inherent limitations: they are either experimentally challenging to implement or confine the beam to a fixed spatial angular velocity, thus restricting functional flexibility. To address these constraints, we propose and experimentally validate a novel class of RSABs constructed by superposing self‐similar Laguerre‐Gaussian (LG) modes, termed LG‐RSABs. Inheriting the exceptional propagation stability of LG modes, LG‐RSABs maintain structural integrity over long‐distance free‐space propagation. Notably, they afford highly tunable orbital angular momentum, dynamically variable spatial angular velocity, and customizable transverse intensity profiles—features beyond the reach of conventional RSABs. Experimental demonstrations confirm that LG‐RSABs facilitate stable optical trapping and precise manipulation of micro‐particles. This work not only deepens the fundamental understanding of self‐accelerating beams but also establishes a new paradigm for constructing advanced RSABs, thereby paving the way for future innovations in advanced structured light optics.