ABSTRACT Phototransistors with high sensitivity and signal gain have unique application potential in optical encryption technology. In this work, a PTCDI‐C 8 /C8‐BTBT organic heterojunction phototransistor (OHPTs) with interface modification was designed, the performance of OHPTs under different interface modifications was compared. The electrical transfer curves of the OHPTs with PVP modified exhibit a wide memory window of up to 92 V, which is because a large number of hydroxyl groups on the surface of the PVP film capture electrons. Under light stimulation, OHPTs exhibits a negative photoresponse and has excellent nonvolatile optical memory, after more than 1000 s of tracking, the current shows almost no attenuation. Finally, based on the array of OHPTs, the simulation of optical encryption applications was completed. Under light stimulation, information can be hidden, and multiple pieces of information can be encoded optically, providing new ideas for the future development of optical encryption technology.

ABSTRACT Metasurfaces represent a class of artificially engineered planar optical devices that achieve exceptional functional performance through optimized nanostructure design and array configurations. These devices have emerged as the predominant methodology for developing integrated, compact optical systems, offering micro‐ and nano‐scale solutions that enable comprehensive multidimensional optical modulation. Here, we report a full‐space switchable optical encryption platform exhibiting wavelength‐dependent information control. Through precisely engineered nanostructures, the system demonstrates three distinct operational regimes: selective reflection revelation without transmission, complete concealment of real‐space information via dual‐holographic encryption, and switchable recovery of both real‐ and k ‐space manifestations across transmission and reflection modes. Spectroscopic characterization and computational modeling reveal the critical role of dielectric nanopillar resonance in enabling these switchable states. This work establishes a paradigm for active optical security devices with potential applications in anti‐counterfeiting, optical communication, switching, and information encryption technologies.

ABSTRACT Controlling excitation‐response and emission tunability in luminescent materials is crucial for high‐security anti‐counterfeiting, but current multimodal materials primarily suffer from static single‐color emission under fixed stimuli, limiting their security potential. Developing a single material with dynamic multichannel emission remains a major challenge. Herein, a multifunctional BiOCl: Yb 3+ , Ho 3+ material with multi‐excitation luminescence, rapid photochromism, and light‐driven dye discoloration has been explored. It emits green up‐conversion emission from Ho 3+ under 980 nm excitation; and broad‐band blue emission from the embedded carbon dots produced during the materials synthesis centers at 470 nm under the excitation of 365 nm, accompanied by a rapid photochromic transition from pale‐yellow to black and reversible process by thermal treatment. The oxygen vacancies in BiOCl: Yb 3+ , Ho 3+ have been confirmed to responsible for the reversibility of the rapid photochromic effect of samples, which also enhance the efficient photocatalytic degradation of Rhodamine B and enable the controllable dye discoloration. These features are integrated into BiOCl: Yb 3+ , Ho 3+ to establish a dynamically tunable multimodal platform, offering a new “concealment‐activation‐erasure‐rewriting” paradigm for next‐generation high‐security anti‐counterfeiting and optical information encryption.

Ratiometric optical thermometers have attracted significant interest due to their high accuracy, self-referencing capability and strong resistance to environmental fluctuations. However, most reported systems rely on doped materials, where random donor-acceptor distributions and batch-to-batch variability hinder reproducibility and restrict practical deployment for high-precision temperature sensing. Molecular ratiometric thermometers with precisely controlled donor-acceptor distances and fixed stoichiometry serve as promising candidates, yet remain largely unexplored. This work reports a dual-center emissive 3d-4f binuclear complex [ZnLSm(OAc)(NO3)2] (ZnSm), constructed using a Schiff base ligand (L). ZnSm exhibits two well-correlated emission bands at 485 nm (ZnL) and 644 nm (Sm3+), enabling quantitative temperature readout over a broad temperature range of 233-333 K with excellent reversibility and a high maximum relative sensitivity of 3.4% K-1. Spectroscopic analyses and theoretical calculations reveal efficient ZnL-to-Sm3+ energy transfer mediated by the bridging Schiff base ligand, accounting for the temperature-dependent dual emission. Moreover, ZnSm can be readily processed into a transparent and flexible poly(methyl methacrylate) (PMMA) film (ZnSm@PMMA) while retaining its ratiometric thermometric performance, thus greatly enhancing its applicability for practical thermal mapping and device-integrated sensing. This work presents a robust molecular design strategy for developing high-performance, dual-center emissive ratiometric optical thermometers. Furthermore, the readily distinguishable color change in the visible range for both ZnSm and its film highlights their potential for advanced optical anti-counterfeiting and information encryption applications.

Skyrmions, topological particle-like spin textures, have drawn significant interest in optics for their potential applications in robust information encoding and photonic manipulation. However, in free space, conventional skyrmionic beams suffer from passive and deterministic transformations in topological textures during propagation due to the Gouy phase effect, consequently limiting their stability and controllability. Here, we experimentally construct customizable Stokes skyrmions, providing unprecedented control over topologies (including skyrmion number and texture helicity) and propagation trajectory. This approach not only ensures the stable preservation of skyrmion textures over long distances but also enables customized transformations between distinct skyrmion types—anti-skyrmions, bimerons, and higher-order skyrmions—without relying on physical transformation elements. More importantly, we realize perfect optical skyrmions experimentally for the first time, to our knowledge. Additionally, we demonstrate the experimental generation of skyrmions along self-accelerating arbitrary trajectories, including parabolic and spiral paths. This work establishes a robust and reconfigurable platform for the manipulation of topological light fields, with significant implications for high-capacity optical coding, encryption, and precision particle manipulation.

The critical requirement for secure image transmission in areas such as surveillance, medicine, and digital forensics has increased the importance of visual information security. Double random phase encryption (DRPE) has been extensively applied in optical image encryption owing to its feasibility in Fourier optics and its capability to encrypt effectively in both the spatial and frequency domains. However, despite these strengths, traditional DRPE techniques have serious drawbacks, including a limited key space, poor resistance to statistical attacks, and vulnerability to cryptographic exploration and known-plaintext attacks owing to the compromise of phase masks. To address these issues, this study proposes an enhanced DRPE (EDRPE) system that combines chaotic key generation based on a logistic map with a dynamic substitution box (S-Box) that offers enhanced confusion and diffusion. Additionally, to address the possible Grover’s attacks on image ciphers, we propose a feature-iterative XOR image encryption (FIXIE) algorithm that generates image-dependent keys across multiple rounds. This new method, to the best of our knowledge, overcomes the inefficacy of classical DRPE by introducing a nonlinear, chaos-driven iterative key evolution model, achieving improved security without compromising computational efficiency. The simulation results indicate that the proposed EDRPE-FIXIE framework achieves strong unified average change intensity values, a high number of pixel change rates, extremely weak correlation between adjacent encrypted pixels, and close-to-ideal entropy. EDRPE-FIXIE fulfills the requirements for real-time and memory-restricted encryption services because these improvements are achieved without compromising memory or processing speed.

Strain-engineered upconversion nanoparticles with controlled Yb3+ doping exhibit power-tunable luminescence through lattice-strain-induced phase transitions. The strain modulation enables stepwise emission activation under varied excitation powers, achieving sequential information display. This single-wavelength excitation, power-gated approach provides a simple yet robust platform for dynamic and secure optical encryption.

Nanoscale chirality has emerged as a dynamic and expanding field of research, with particular emphasis on systems that exhibit optical activity in both the ground and excited states, enabling promising prospects in areas such as enantioselective catalysis, circularly polarized photonics, advanced bioimaging, anti-counterfeiting technologies, and optical data encryption. In contrast to larger nanoparticles, where surface irregularities often complicate the correlation between structure and properties, atomically precise metal clusters serve as accurate model systems in which chiral features can be directly correlated with atomic-level arrangements and electronic structures. Recent developments have uncovered several distinct mechanisms through which chirality manifests in these systems. These include: (i) intrinsic asymmetry within the metal core, or asymmetric orientation of achiral ligands, originating from optically inactive starting atomic configurations; (ii) chirality introduced via optically active surface protecting ligands, where chiral organic molecules transfer or enhance handedness through steric constraints and electronic coupling at the metal-ligand interface; and (iii) supramolecular organization, wherein individual clusters assemble into helically ordered or anisotropic architectures that exhibit collective chiroptical activity. This review brings together these diverse origins of chirality to offer a comprehensive understanding of their structural and physico-chemical bases. Moreover, we highlight how the three distinct origins of chirality in metal clusters differ in their synthetic accessibility and their typical impact on chiroptical behaviour. By putting forth such a perspective, the effort aims not only to advance the fundamental understanding of the mechanisms underlying chirality at the nanoscale, but also to build conceptual frameworks crucial for directing the development of next-generation chiral nanomaterials with tailored characteristics.

In recent years, the use of speckle patterns has gained increasing attention in the context of optical encryption. Conventional scattering media (CSM), due to their fixed functionality, are mostly limited to single-channel encryption, which restricts further improvements in system security. Metasurfaces, as two-dimensional devices capable of flexibly manipulating optical parameters, provide an ideal platform for achieving multiplexing functionality. Building on this foundation, we propose a polarization-multiplexed disorder-encoded metasurface (DEM) for multi-channel optical encryption. This DEM enables dual encryption through quick response (QR) code cascading and provides six encryption channels to the system. The encryption capability of the DEM-based system has been verified through security attack analysis. The proposed DEM effectively expands the number of channels and enhances the data capacity of the encryption system, thereby significantly improving security and attack resilience, demonstrating promising potential for practical applications.

Cellulose nanocrystal (CNC) photonic films have emerged as sustainable alternatives to traditional pigments by harnessing cholesteric nanostructures for vivid, fade-resistant colors. However, scalable fabrication of continuously functionalized structural color patterns directly from CNC dispersion remains a grand challenge due to limitations in conventional printing techniques and coassembly approaches. Here, we present a bioinspired sequential nanofluidic-assisted photonic patterning (SNAPP) technique that leverages preformed cholesteric CNC films with three-dimensional helical nanochannels as self-regulated pathways for spontaneous ink diffusion. Mimicking nature's helical Venturi effect, this technique enables universal integration of diverse functional components (molecules, polymers, and nanoparticles) to manipulate photonic band gaps or impart stimuli-responsive functionalities while preserving long-range chiral order. By combining mask-guided patterning with capillary-driven transport, we achieve full visible-spectrum structural colors, humidity/thermal-responsive patterns, and fluorescent carbon dot integration with 4-fold enhanced emission intensity and circularly polarized luminescence. The resulting films retain angle-dependent iridescence and polarization selectivity, while exhibiting exceptional environmental stability, biocompatibility, and degradability. This multifunctional platform enables dual-channel optical encryption with orthogonal authentication modes (structural color, fluorescence, thermochromism, and circular polarization), positioning it as a high-security anticounterfeiting solution for pharmaceutical applications. The SNAPP technique overcomes the fundamental limitations of traditional methods, offering a scalable, versatile route to functional photonic materials with programmable dynamic responses.

Reconfigurable metasurface holography in the visible region is hindered by the trade-off between optical loss and phase tunability. We report a reconfigurable visible metasurface hologram operated at a fixed wavelength, enabled by the reversible phase transition of an Sb2S3 phase-change metasurface. The device integrates nonvolatile switching with complementary polarization multiplexing and a computationally optimized phase framework to achieve on-demand control of multiple holographic channels without altering geometry. In the crystalline state, two distinct images are reconstructed under orthogonal linear polarizations (x and y), whereas in the amorphous state, two additional images are activated under left- and right-handed circular polarizations (LCP and RCP). An iterative Fourier-Adam optimization establishes a shared base phase that maintains interchannel orthogonality, suppressing crosstalk and enhancing reconstruction fidelity. The low-loss, nonvolatile Sb2S3 platform provides a scalable route toward compact optical encryption and programmable visible photonics.

The development of smart circularly polarized luminescence(CPL)systems with dynamically tunable emission properties presents botha significant challenge and a compelling opportunity in advanced photonics.Herein, we report a light-responsive CPL system fabricated by dispersingachiral Coumarin 6 and a photochromic spiropyran derivative withina self-organized chiral nematic liquid crystal (N*-LCs) matrix. Theregular helical superstructure of the N*-LCs host not only inducesthe emergence of pronounced CPL signals from the achiral dopants butalso provides a photonic bandgap (PBG). Through the efficient Försterresonance energy transfer (FRET) process from the donor Coumarin 6to the photoisomerized merocyanine form of the acceptor, the CPL emissionis reversibly switched from green to red upon UV light irradiation.Concurrently, the luminescence dissymmetry factor (glum) is significantly enhanced from 0.2 to 0.95, whichis attributed to the precise spectral alignment of the new red emissionwith the PBG center of the chiral medium. This strategy of leveragingthe photonic effect for amplification, combined with a photon-controlledFRET, enables dynamic and reversible tuning of both the color and glum of CPL, offering a versatile platform forapplications in programmable optical encryption and next-generationanticounterfeiting technologies.

Holography has emerged as a vital platform for three-dimensional displays, optical encryption, and photonic information processing, leveraging diverse physical dimensions of light such as wavelength, polarization, and orbital angular momentum (OAM) to expand multiplexing capacity. However, the exhaustive utilization of these intrinsic degrees of freedom has saturated the parameter space for holographic encoding, leaving no room for further scalability. Here, we demonstrate an OAM multiplication operator enabled holographic multiplexing. We engineer the operator-specific hologram that selectively responds to the predefined operator pathway. Subsequent validation of orthogonality between distinct operator pathways ensures the multiplexing ability, thereby enabling the parallel encoding of multiple holographic images. In the experiment, we have successfully demonstrated a ninefold capacity enhancement over conventional OAM holography and a 2-bit operator-multiplexed hologram for high-security optical encryption. This work introduces operators as a synthetic dimension beyond light’s intrinsic properties into holography, unlocking a scalable and secure paradigm for ultrahigh-dimensional information technologies.

Nonlinear optical metasurfaces have emerged as a powerful platform for efficient and multi-dimensional manipulation of harmonic waves, offering distinct advantages such as high-integration capability and phase-matching-free operation. Spin and orbital angular momentum (SAM and OAM) provide rich degrees of freedom for advanced light field control. While SAM- and OAM-multiplexing metasurface holograms have been realized in the linear optical regime, their performance is hindered by a low signal-to-noise ratio stemming from residual light mode conversion. Nonlinear OAM holography has recently been demonstrated; however, its practicality remains limited by reliance on bulky nonlinear optical crystals that exhibit only intrinsic spin-orbit interaction (SOI). Here, we introduce nonlinear SOI holography via second harmonic generation on optical metasurfaces composed of gold plasmonic meta-atoms. By controlling the local rotational symmetry and topological charges, these metasurface holograms can fully harness optical SOI through both intrinsic and extrinsic angular momentum mode conversions. Information hidden in second harmonic holographic images can only be reconstructed from the spin-orbit tomography of the fundamental waves, ensuring high-security nonlinear optical encryption. The proposed approach offers promising applications in optical communications, optical information processing, high-dimensional optical storage, and so on.

Precise regulation of color rendering and multidimensional optical encryption enabled by electrically tunable all-dielectric grating devices

Single-sized silicon metasurface for three-channel and nested optical encryption

In optical imaging and sensing applications, reliable and efficient medical image encryption is essential for secure transmission. This work proposes a novel, to the best of our knowledge, security scheme that integrates a bio-interactive system (predator-prey model), compression techniques, and multi-directional diffusion, with emphasis on compatibility with optical sensing. Dynamic characteristics of the bio-interactive system are analyzed to confirm high randomness suitable for encryption. Based on compressive sensing principles, a dynamic threshold is introduced and a measurement matrix constructed via bio-interactive system to enhance reconstruction quality. A multi-directional diffusion mechanism is furtherly designed, which spreads along rows, columns, and diagonals, thereby enhancing diffusion affect. This scheme is verified to feature high key sensitivity, strong robustness against computational attacks, and efficient performance suitable for real-time optical medical image encryption.

ABSTRACT The helical supramolecular cholesteric liquid crystals (CLCs) are an intrinsic chiral photonic structure that strongly enhances, enabling the amplification of circularly polarized luminescence (CPL) emission intensity and dissymmetry factors. However, the inherent mechanical fragility of CLCs causes them to readily deform under external stress, causing luminescence quenching and restricting their use in strain‐responsive solid‐state devices. To address this limitation, a femtosecond laser‐engineered microporous cholesteric liquid crystal elastomer (FLCLCE) is developed and integrated with achiral CdSe/ZnS quantum dots (QDs) to yield a robust and tunable CPL‐active material. The resulting FLCLCE‐QD composite exhibits strain‐tunable CPL and vivid structural color changes. The stress‐induced mechanochromic response is amplified by laser‐fabricated microporous arrays within the elastomer, simultaneously producing a unique checkerboard‐like optical pattern that enables dynamically adjustable CPL signals. Furthermore, by coupling the mechanically modulated color shifts with programmable CPL emission, the material supports the design of a multilevel optical anti‐counterfeiting system. Overall, this strategy provides a pathway to advanced applications in dynamic optical encryption and wearable polarization‐sensitive technologies.

Abstract 0D organic‐inorganic metal halides (OIMHs) with excitation‐wavelength‐dependent emissions have emerged as ideal materials for multiplexed anti‐counterfeiting and information encryption. However, exploring multiple fluorescence/phosphorescence emissions stemming from distinct active centers within OIMHs remains challenging. Here, a phosphonium salt, [BCDBP]Br (BCDBP = butyldicyclohexyl(2′,6′‐dimethoxy‐[1,1′‐biphenyl]‐2‐yl)phosphonium), which exhibits room‐temperature phosphorescence (RTP) and anti‐Kasha emission, is synthesized. This phosphonium salt is successfully employed to prepare a series of 0D OIMHs [BCDBP] 2 Zn 1−x Mn x Br 4 . The [BCDBP] 2 ZnBr 4 preserves RTP and anti‐Kasha behavior originating from the organic unit [BCDBP] + while simultaneously achieving self‐trapped exciton (STE) emission from [ZnBr 4 ] 2− . Further analyses confirmed that the incorporation of [ZnBr 4 ] 2− also suppresses non‐radiative decay, boosting the PLQY and extending phosphorescence lifetime. Furthermore, Mn 2+ doping introduces [MnBr 4 ] 2− emission centers, enabling [BCDBP] 2 Zn 0.998 Mn 0.002 Br 4 to exhibit rich excitation‐wavelength‐dependent emission from three distinct emissive centers: [BCDBP] + , [ZnBr 4 ] 2− , and [MnBr 4 ] 2− . This work successfully integrates an organic unit exhibiting anti‐Kasha emission with two distinct inorganic emissive centers into a single material platform, where all components remain optically active and selectively addressable under specific excitation conditions. The strategy of assembling multimodal emissions within a single material demonstrates exceptional potential for advanced optical encryption and anti‐counterfeiting applications.

ABSTRACT Grafted perfect vector vortex beams (GPVVBs) expand the spatial encoding capacity of structured light by combining multiple degrees of freedom within a single beam. However, the current implementation schemes remain constrained by two critical challenges: intrinsic conjugate loss and limited topological charge combinations. Here, we present a diatomic metasurface platform that directly modulates the polarization‐dependent complex amplitudes of incident light, producing a single on‐axis output beam and eliminating the intrinsic conjugate loss of Pancharatnam–Berry phase designs. To achieve high‐degree‐of‐freedom GPVVBs, we introduce a global phase‐compensation strategy that enforces boundary continuity and admits arbitrary integer, fractional, or hybrid topological charge combinations, substantially enhancing the accessible mode space. As a proof of concept, we fabricate a metasurface array generating parallel‐channel double‐ring GPVVBs and demonstrate secure optical encryption across four independent information channels. This integrated approach combines high efficiency, full programmability of beam scaling, rotation, polarization order, polarization ellipticity, and exceptional scalability of the encoding space. Our results establish phase‐compensated GPVVB metasurfaces as a compact and versatile platform for high‐capacity secure information processing, optical trapping, and other advanced photonic applications.