We present a reference-free holographic telepresence framework that captures and replays the complex optical wavefront of a three-dimensional scene from a single intensity speckle measurement. A pre-characterized geometric phase diffuser encodes the incident field into a deterministic speckle pattern, enabling reference-free acquisition through a calibrated, invertible forward model. The wavefront is recovered via scattering-matrix inversion with smoothed amplitude flow and Nesterov acceleration, and directly projected onto a spatial light modulator for holographic replay. This measurement-driven pipeline eliminates interferometric reference beams and multi-frame acquisition, enabling single-shot operation at video rate (similar to 28 fps) with sub-gigabit bandwidth. We experimentally demonstrate volumetric refocusing and dynamic three-dimensional reconstruction, confirming that the recovered field preserves physically consistent propagation behavior. Although image quality is currently limited by coherent speckle, both experiments and simulations show systematic improvement with temporal averaging and system scaling. These results establish real-time, measurement-based wavefront capture and replay as a viable and complementary approach to model-based holographic telepresence.
Multicore fibers (MCFs) are perspective for telecommunications, sensing, imaging, and laser technologies. Here, the effect of spatiotemporal beam stirring between weakly coupled cores is observed for sub-nanosecond narrowband pulses of several kW peak power propagating in similar to 10 m long 7-core fiber, for the first time to our knowledge. In contrast to the low-power domain where the output power distribution in the cores is random with large fluctuations sensitive to fiber disturbances, at high power of the input pulse injected in the central core the output power becomes equalized between the cores with fluctuations reduced to <5% being insensitive to disturbances. Similar behavior is observed in cut-back experiments showing that equi-partition is approached at a distance of similar to 5 m. The performed modeling describes well the experimental results and clarifies mechanisms of the new effect caused by a large nonlinear phase shift changing along the pulse and thereby resulting in statistical averaging over the pulse length of multidirectional power transfer processes between cores, thus leading to the robust equilibrium (equipartitition for hexagonal MCF topology). At the same time, the combined output beam measured in a far field takes a stable bell-shaped profile instead of speckled beam at low powers, similar to the beam self-cleaning effect in multi-mode fibers.
The notion of a path in quantum mechanics has fuelled many debates on the very nature of what quantumness is. Although traditionally associated with physical paths, such as double slits, it can be far more abstract. Now Yan Wang and colleagues demonstrate exotic trajectories in an abstract quantum space built from the Bloch sphere of a locally entangled photon, while shaping the path using its non-local entangled partner as a control. The steering and directing along these new paths is enabled by cascaded metasurfaces, demonstrating the myriad of possibilities that emerge when structured matter meets quantum structured light.
Cancer treatments, dependent on several factors, deliver varying degrees of treatment effectiveness. Photodynamic therapy (PDT) is a treatment modality that selectively targets and destroys cancer cells using a lightsensitive drug with a specific optical wavelength. However, PDT encounters several constraints, mainly, limited penetration of light into deep tumors. In this paper, we present a new wireless implantable PDT system towards overcoming the constraints of current PDT treatments. The wireless-powered prototype was evaluated showing resonant inductive power delivery in a tissue phantom, emulating the bladder, providing the necessary power level for PDT treatment. The production of singlet oxygen (1O2) using a multi-LED system was studied by utilizing a 1,3-diphenylisobenzofuran (DPBF) in a Rose Bengal (RB) and Dimethyl sulfoxide (DMSO) solution, under both DC and AC excitations, for direct wireless powering. The photosensitizer solution is illuminated with over 5 mW of optical power generated by the four-LED array to generate 1O2. Our measurements confirm the production of 1O2 emissions as well as lifetime performance. The optical, electrical, and mechanical studies are presented on the resultant optoelectronic system, verifying the efficiency and mechanical robustness of our prototype. A fabrication flow for biocompatible devices using laser ablation is also introduced towards large area manufacturability, scalability, and repeatability. Our manufacturing process is versatile to a variety of materials including polymeric substrates, metallic electrodes and offers design flexibility ranging from 30 microns to mm. This research advances the development of wirelessly powered implantable device for PDT, optimized for in-vivo use through careful LED selection and biocompatible design. Our results evidence the potential of a new emergent technology that addresses the limitations of PDT as a potential future therapy to enhance the curative efficiency of cancer treatment and demonstrates promising preliminary potential for in vivo application, which requires further validation before therapeutic implementation can be established.
Reconfigurable intelligent surfaces (RISs) transcend the passive response limitations of conventional meta-surface resonators by integrating active materials into metasurface elements, enabling a more flexible control of electromagnetic wave properties. However, RISs devices operating in the terahertz (THz) regime continue to face significant challenges in structural design and multifunctional implementation, particularly regarding optically-addressed THz RISs devices with independent pixel-level encoding, which remain experimentally underexplored. Here, we propose a compact and relatively efficient transmissive programmable metasurface device functioning as a phase-type spatial THz modulator, which enables separate encoding of each pixel within a 50 & times;50 resolution array, thereby achieving dynamic generation and reconfiguration of THz wavefronts. The spatial modulation of the pump pulse intensity locally activates the vanadium dioxide integrated meta-atoms across the metasurface and, thus, defines the specifically designed phase modulation of the cross-polarized transmission. Dynamic wavefront manipulation is then realized by switching the spatial intensity distribution of the pump pulse. Proof-of-concept experiments demonstrate that the same programmable metasurface can perform three distinct functionalities -zoom lens, tunable vortex beam generator, and dynamic hologram. The amplitude conversion efficiency of the device was experimentally measured to be 27%. The programmable scheme demonstrated here paves the way toward miniaturized, integrated, and multifunctional THz optical devices.
Thermophotovoltaics (TPVs) are solid-state photonic heat engines that convert thermal radiation into continuous power generation through photovoltaics. Recent work on photon recuperation using back-surface reflectors has remarkably boosted TPV efficiencies. However, building a practical TPV device with photons actually recuperated remains a challenge because of the strong emitter-cell thermal coupling. Here we build a robust TPV device through emitter-side photon recuperation using a spectral-heat filter (SHF). The SHF, optimized via multi-objective machine learning, blocks 99% of the sub-bandgap radiation as well as the thermal conduction and convection from the emitter. The accelerated thermal ageing test shows the fabricated SHF has a L70-rated lifetime of 57,477 hours. The emitter-SHF pair decouples the temperature-susceptible PV cell from the photon-recuperation process, and unlocks the mass-produced state-of-the-art photovoltaic cells for use in TPV. The emitter-SHF pair engineers the above-bandgap radiation to achieve current matching in the GaInP/GaAs/Ge triple-junction photovoltaic cell. The efficiency of the TPV device reaches 47.16% +/- 1.12% at the emitter temperature of 2,162 degrees C. The spectral-heat filtering architecture offers inherent operational robustness as well as the power conversion efficiency surpassing conventional heat engines.
Semiconductor metasurfaces have emerged as an effective platform for all-optical modulation thanks to their resonant light confinement and the enhancement of ultrafast optical effects like the Kerr effect and free-carrier generation. However, their narrow resonance features also restrict the available bandwidth for efficient modulation. Here, we demonstrate that a kink-like transmission spectral profile of a silicon metasurface could enable high-contrast modulation of wide-bandwidth pulses. We studied the all-optical ultrafast transmission modulation of the silicon metasurface induced by free-carrier excitation in a pump-probe configuration at different polarizations. We achieved ultrafast modulation of 28% (10%) with a speed of 25 ps and a bandwidth of up to 14 nm (49 nm) for y-and x-polarizations, respectively. Our results open up new opportunities for high-contrast, all-optical modulation of short pulses, with applications in optical communications and computing.
Evanescent coupling is central to integrated photonics, enabling essential functions such as power splitting, routing, and beamforming, yet it also fundamentally limits photonic integration density through crosstalk and strong wavelength dispersion. Achieving broadband suppression and control of coupling in densely packed waveguide arrays remains a long-standing challenge. Here, we present an artificial gauge field (AGF)-based strategy that enables both wavelength-insensitive coupling suppression and dispersionless, arbitrary-ratio power splitting on a silicon-on-insulator platform. By jointly engineering waveguide trajectory modulation and propagation-constant mismatches introduced through non-uniform waveguide widths, we realize a half-wavelength-pitched dense waveguide array with a center-to-center spacing of 750 nm, far below conventional coupling-limited separations. The resulting array exhibits broadband crosstalk suppression below-20 dB over a 100-nm wavelength range (1500-1600 nm) with negligible excess loss. In parallel, we demonstrate AGF-enabled directional couplers with colorless and programmable splitting ratios, achieving wavelength-independent power division across the same bandwidth. Leveraging these near-dispersionless couplers, we construct a broadband Gaussian-weighted waveguide array and experimentally realize a two-dimensional optical phased array with a field of view of 120 degrees & times; 14.5 degrees and sidelobe levels below-17 dB. Our work establishes a scalable framework for broadband coupling control in ultra-dense photonic circuits, opening new opportunities for compact optical phased arrays, photonic delay lines, and high-capacity space-division multiplexing systems.
This work addresses the challenge of fabricating crystalline single-phase luminescent 3D microstructures by demonstrating a fabrication process of yttrium aluminum garnet doped with cerium (YAG:Ce3+) 3D micro-objects. Precursors were synthesized via a sol-gel method and characterized by refractive index (RI) measurements, Fourier-transform infrared spectroscopy (FT-IR), and thermogravimetric (TG) analysis to verify chemical composition changes during photopolymerization and thermal treatment. Multiphoton laser 3D lithography (MP3DL) was employed to produce hybrid metal-organic 3D structures, which were subsequently converted into crystalline ceramics through controlled 3-step annealing. Structural analysis by X-ray diffraction (XRD) confirmed the formation of single-phase cubic YAG across Ce3+ concentrations up to 5 mol-% in 3D objects, while scanning electron microscopy (SEM) revealed isotropic shrinkage (ca. 39%) and well-preserved geometries with sub-micrometer features after pyrolysis. The smallest feature of a crystalline 3D object achieved was 0.48 mu m with a spatial resolution down to 2.4 mu m. Luminescence measurements showed characteristic Ce3+emission centered at 558 nm, with maximum intensity at 2 mol% doping. These findings establish a reliable pathway to fabricate thermally stable, high-resolution, luminescent single-phase YAG:Ce3+ 3D micro-objects, enabling their integration into optoelectronic and photonic applications.
The rapid integration of deep learning in medical image diagnosis is challenged by the energy inefficiencyand data bottlenecks of conventional electronic computing. Photonic Neural Networks (PNNs) offer a promising,ultra-parallel computing paradigm to overcome these limitations. In this work, we present a high-performance elec-tro-optic modulator realized by synergizing the exceptional properties of a phosphorene-based van der Waalsheterostructure with the enhanced light-matter interaction of a microring resonator. This design achieves efficient,low-power modulation with a high modulation efficiency of 0.25 V & centerdot;cm. We utilized this modulator to construct aprototype all-fiber PNN based on a time-division multiplexing architecture. To improve computational precision, weemployed a Ring-Assisted Mach-Zehnder Interferometer (RAMZI) structure, effectively extending the linear operat-ing region for precise weight matrix representation. Experimental validation confirms the PNN's robust and accurateperformance in complex tasks, including handwritten digit classification, retinal B-scan analysis, and multiphase liverCT image diagnosis. This study introduces a high-efficiency electro-optic modulation scheme and lays the foundationfor highly integrated, low-power, fiber-based PNNs for accelerated and efficient medical diagnostics.
The convergence of artificial intelligence (AI) and metaphotonics is creating a new paradigm for controlling light-matter interactions. The synergy of AI's ability to learn complex relationships in multidimensional data and provide ultra-fast inference with the capacity of metaphotonics to engineer optical properties not found in nature is unlocking a new era in computational design, real-time control, and fully automated optical systems. This review provides a comprehensive overview of state-of-the-art AI-driven approaches for metaphotonic systems. We focus on the solutions to real-world problems in accelerating metaphotonic simulations and inverse design, optical data characterization, and the development of fully integrated end-to-end AI-assisted metaphotonic systems. Finally, we provide our perspectives on the future research directions and emerging opportunities at the rapidly evolving intersection of metaphotonics and AI.
Thermal infrared (IR) detectors represent a crucial technology for various applications, yet achieving high performance without cooling remains challenging. Here, we demonstrate high-performance broadband IR photodetectors by integrating single-walled carbon nanotubes (SWCNTs) with a ferroelectric substrate, leveraging the pyroelectric effect for enhanced photodetection. Using aerosol chemical vapor deposition and capillary transfer techniques, we fabricate sparse SWCNT films on z-cut LiNbO3 surfaces to create pyroelectrically gated field-effect transistors. The devices exhibit remarkable responsivity across the IR spectrum, with semiconducting channels achieving maximum relative responsivities reaching nearly 100 %/mu W at 1550 nm. Our optimized SWCNT networks demonstrate exceptional specific detectivities of 1.7 & times; 1010 cm,/Hz/W at 1550 nm and 1.4 & times; 1010 cm,/Hz/W at 9.3 mu m, surpassing graphene-based alternatives by several orders of magnitude and approaching theoretical limits. These results establish SWCNT-based pyroelectric photodetectors as promising candidates for room-temperature IR detection, eliminating the conventional requirement for cooling.
Optical computing systems (OCS) are promising accelerators for artificial intelligence due to their high bandwidth, low latency, and inherent parallelism. However, in existing OCS implementations, task development often requires direct participation of physical hardware during training and optimization, tightly coupling development workflows to device access and limiting offline design, reproducible benchmarking, and parallel exploration. Here, we propose a Digital Twin Optical Computing System (DT-OCS), a system-level, measurement-driven digital surrogate that emulates the end-to-end input-output behavior of a specific physical OCS under different operating configurations. DT-OCS is implemented as a differentiable software module, enabling fully offline task training and configuration optimization. The optimized configuration parameters can be directly transferred to the physical OCS without hardware-in-the-loop retraining. We validate DT-OCS on a high-speed optical computing system operating at 10 GHz and equipped with a silicon-based integrated computing chip. Representative tasks, including image classification and temporal strategy generation, are evaluated. Across all tasks, the transferred models closely match the performance of their digital-twin counterparts after direct parameter transfer. These results demonstrate that DT-OCS enables a hardware-decoupled and fully offline development paradigm for optical computing systems. The DT-OCS implementation is released as open-source code to facilitate reuse and further development.
Optical beam steering is essential for free-space optical communication, light detection and ranging (LiDAR) and other fields. Thin-film lithium niobate (TFLN), as an efficient integrated photonics platform, offers strong electrooptic (EO) effect, low propagation loss, high-speed, and low-power modulation, making it highly attractive for optical phased array (OPA) based beam steering. However, despite these advantages, OPAs still face inherent trade-offs among field of view, sidelobe suppression, and scanning resolution. Recently, Prof. Huihui Lu's group presented a two-dimensional (2D) EO-steered OPA using a non-uniformly spaced X-cut TFLN superlattice-waveguide array and a trapezoidal grating emitter. The compact device achieves narrow main beam, wide steering range and high sidelobe suppression, demonstrating great potential for high-performance beam-steering applications.
Achieving realistic depth perception in augmented reality (AR) displays remains a central challenge due to the reliance on single focal planes. In the recent work published in Opto-Electronic Science, researchers from Beijing Institute of Technology and their collaborators report a hybrid metasurface-freeform optical architecture that enables simultaneous multi-focal plane display within a compact, solid-state system. By combining polarizationmultiplexed metasurfaces with freeform optics through a joint design framework, the system generates multiple depth cues without time multiplexing and remains compatible with practical display hardware. This work highlights a promising route toward cross-scale optical co-design for realistic near-eye display systems.
