Light, science & applications最新文献

Encoding information across multiple degrees of light, including spin, wavelength, amplitude, and phase into the multi-level structures of a stimuli-responsive material, presents a highly promising strategy for optical encryption. Here, we present a biphasic chiral photonic crystal platform that addresses the intrinsic coupling among photonic spin, wavelength, and functions, thus providing a multi-parameter security framework that substantially enhances encryption complexity. By integrating two separately photopatternable chiral photonic crystals with opposite handedness into a single cell, independent geometric phase modulation for orthogonal spins and discrete wavelengths is fully released. The near-field polarization interference imaging and far-field spin-multiplexed holography with partly temperature-robust and partly thermally responsive information are demonstrated. Furthermore, we concealed the latitude and longitude coordinates of a destination across two separate far-field images, which are only revealed at the correct combination of temperature, optical spin, and wavelength. This biphasic system fully harnesses light's potential for advanced encryption, which will drastically enhance the security of secure logistics, anti-counterfeiting, and hardware authentication.

The integration and miniaturization of chips lead to significant power consumption and heat accumulation. Typically, the energy consumption of cooling systems accounts for morn than 50% of the input energy. Current thermal management technologies do not offer solutions for on-chip thermal energy loss. Herein, we propose an on-chip integrated thermal recovery system, which can simultaneously achieve efficient heat dissipation. Present system on chips is based on hydrovoltaic generator technology, consisting of electrodes and gel. With the deep ultraviolet LED (236 nm) chip suffering from severe heat accumulation as a prototype, upon integration with the thermal recovery system, not only maintain the chip temperature below 40 °C, but also converts waste heat into stored electrical energy, resulting in a 610.70% improvement in overall energy utilization efficiency. To demonstrate its general applicability in commercial CPU systems, we used the commercial Intel G3220 chip and as an example, by incorporating four HEG units, the temperature was reduced from 93 °C to below 60 °C, effectively enhancing computational performance and extending the chip's lifespan.

A meta-aspheric lens fabricated at the wafer-level achieves a 101.5° field of view, a 3.39 mm total track length, and an F/1.64 aperture within a volume of 0.02 cm³, enabling compact and scalable near-infrared imaging.

A new optical in-memory computing system based on an array of vertical-cavity surface-emitting lasers (VCSELs) has the potential to circumvent the Von Neumann bottleneck. The high modulation speed of the lasers in the array allows for fast computing and their high efficiency can enable edge computing in autonomous vehicles and drones. This efficient, highly scalable system was demonstrated to perform 900 million convolutions per second with 98% computing accuracy.

Arrays of resonant nanoparticles, so-called metasurfaces, have been developed and demonstrated as the first generation of meta-operators. Unlike today's electronic systems, the demonstrated compact, scalable platform enables ultrafast, energy-efficient all-optical image processing, extending to holographic wavefront shaping with a single-layer metasurface. These results open new opportunities for advanced optical computational microscopy and intelligent sensing.

The scalable integration of solid-state quantum emitters into photonic nanostructures remains a central challenge for quantum photonic technologies. Here, we demonstrate a robust and streamlined integration strategy that tackles the long-standing issue of deterministic fabrication on randomly positioned self-assembled quantum dots (QDs), leveraging a buried-stressor-based site-controlled InGaAs QD platform. We show that this deterministic growth approach enables precise spatial alignment with circular Bragg grating (CBG) resonators for enhanced emission, eliminating the need for complex and time-consuming deterministic lithography techniques. We fabricated a 6 × 6 SCQD-CBG array with 100% device yield, with 35 devices falling within the radial-offset range where the simulated photon-extraction efficiency (PEE) exceeds 20%, underscoring the spatial precision and scalability of our fabrication concept. A systematically selected subset of five devices with varying radial displacements reveals clear offset-dependent trends in PEE, degree of linear polarization, spectral linewidth, and photon indistinguishability, thereby establishing quantitative bounds on spatial alignment tolerances. In the best-aligned QD-CBG device, we achieve a PEE of (47.1 ± 3.8)% (corresponding to an end-to-end system efficiency of 3.4%), a linewidth of (1.41 ± 0.22) GHz, a radiative decay lifetime of (0.80 ± 0.02) ns, a single-photon purity of (99.58 ± 0.18)%, and a Hong-Ou-Mandel two-photon interference visibility of (81 ± 5)% under quasi-resonant excitation at saturation power. We confirm our conceptual understanding of the effect of emitter-position dependent charge-noise fluctuations in terms of a quantum-optical model for the (quantum-)emission properties. The established nanofabrication platform provides a reproducible, lithography-compatible route to scalable, high-performance single-photon sources (SPS), offering a powerful alternative to conventional lithography-based deterministic integration techniques.

Deep-blue phosphorescent OLEDs (Ph-OLEDs) with high efficiency and stability are essential for advanced display technologies, ensuring sharp image quality and enhanced visibility. In this work, we report a novel class of asymmetric [3 + 2 + 1] coordinated iridium(III) complexes incorporate strongly electron-withdrawing trifluoromethyl (-CF₃) and fluorine (-F) modified N-heterocyclic carbene ligands. This strategic molecular design enables efficient deep-blue emission. Among these complexes, the CF₃-substituted Ir(III) complex (CF₃-2) exhibits pronounced charge-transfer (CT) characteristics and a significantly enhanced radiative decay rate ( $k_r$  = 1.28 ×10⁶ s^-1), enabling rapid and efficient phosphorescence at 443 nm. Devices employing CF₃-2 demonstrated exceptional maximum external quantum efficiency (EQE_max) of up to 29.0%, with emission centered at 443 nm and Commission Internationale de L'Éclairage (CIE) coordinates of (0.147, 0.089), fulfilling National Television System Committee (NTSC) blue standards for high-quality displays. Meanwhile, devices employing CF₃-1 reached an EQE_max of 24.6% with a maximum luminance of 6542 cd m^-2 and CIE_x,y of (0.152,0.126), demonstrating high color purity and efficiency. A control device fabricated without sensitization using CF₃-1 further confirms its intrinsic material stability by exhibiting a remarkable operational lifetime of LT₅₀ of 3875 h at L = 100 cd m^-2 with CIE_x,y of (0.132,0.131). Furthermore, hyper-OLEDs were developed using these complexes as phosphorescent sensitizers. The hyper-OLED incorporating CF₃-1 with the TADF emitter v-DABNA achieved an impressive device lifetime of LT₅₀ = 2127 h at 100 cd m^-2. In parallel, the CF₃-2-sensitized hyper-OLED using DOB2-DABNA-A achieved a deep-blue emission with CIE coordinates of (0.146, 0.067) and a lifetime of LT₅₀ = 373 h under the same luminance, representing a significant advancement in the practical stability of deep-blue OLEDs. Notably, we demonstrate the successful integration of these deep-blue Ph-OLEDs with OLED-on-TFT microdisplay technology, achieving a pixel resolution of 94 PPI (270 × 270 μm) with programmable emission patterns. This innovative molecular coordination design strategy provides valuable insights into ligand engineering and exciton management, opening new pathways toward high-efficiency, long-lifetime deep-blue OLEDs for next-generation microdisplay and display technologies.

The advent of foundation models initiated a paradigm shift in pathology and optical microscopy. However, these powerful systems also introduce vulnerabilities, making them susceptible to adversarial attacks. To shed light on these potential threats, here we introduce Universal and Transferable Adversarial Perturbations (UTAP) for pathology foundation models that reveal critical vulnerabilities. Optimized using deep learning, UTAP comprises a fixed and weak microscopic noise pattern that, when added to a pathology image, systematically disrupts the feature representation capabilities of foundation models. Therefore, UTAP induces performance drops in downstream tasks that utilize foundation models, including misclassification across a wide range of unseen data distributions. We demonstrate two key features of UTAP: (1) universality: its microscopic perturbation can be applied across diverse field-of-views independent of the dataset that UTAP was developed on, and (2) transferability: its perturbation can successfully degrade the performance of various external, black-box pathology foundation models-never seen before. These indicate that UTAP is not a dedicated attack associated with a specific foundation model or microscopy image dataset, but rather constitutes a broad threat to pathology foundation models and their applications. We evaluated UTAP across various state-of-the-art pathology foundation models on multiple datasets, causing significant drops in their performance with visually imperceptible microscopic modifications to the input images using a fixed noise pattern. The development of these potent attacks establishes a benchmark for model robustness evaluation, highlighting a need for advancing defense mechanisms to ensure the safe/reliable deployment of AI in pathology and optical microscopy.

Photoacoustic tomography as an optical-ultrasound hybrid imaging modality provides rich optical contrast over the extended penetration depth of biological tissues, enabling multiscale multicontrast structural and functional imaging. However, inherent limitations in the state-of-the-art piezoelectric transducer arrays of the photoacoustic tomography, including size-dependent sensitivity, narrow bandwidth, and high material rigidity, compromise the resolution, penetration depth, and functional assessment precision. Here, an arc-shaped fiber ultrasound transducer array with a sheet-like ultrasound focus is demonstrated for photoacoustic computed tomography. At the ultrasound focus, a low detection limit of ~ 5.2 Pa and a dual-frequency response spanning several octaves are achieved. Whole mouse brain imaging with a depth up to ~ 1.2 cm and a spatial resolution of ~ 70 μm in the cerebral cortex region is showcased. The blood oxygen saturation within the entire mouse brain and the brain tumors is visualized, and the assessment precision is improved by leveraging the dual-frequency response of the transducer array. The centimeter-scale imaging depth, fine resolution of the cerebral vessels, and improved precision in the blood oxygenation evaluation make the fiber-array photoacoustic tomography a competitive candidate to the sought-after magnetic resonance imaging and ultrasound localization microscopy for brain functionality study and disease diagnosis.

Bound states in the continuum (BICs) are optical states that remain perfectly confined despite existing within the radiation spectrum, enabling strong light confinement and light-matter interactions. These unique properties make BICs a promising platform for high-performance photonic crystal lasers. However, achieving robust, single-mode BIC lasers with compact footprints remains challenging due to mode competition and fabrication imperfections. Here, we demonstrate a robust single-mode laser by leveraging the concept of "merging BIC" in momentum space, which enables stable lasing behavior up to 80 times the threshold power, showcasing exceptional mode stability under high-power excitation. Furthermore, we realize an ultra-compact photonic crystal laser by combining the BIC mode with edge engineering, achieving a 5 × 5 periodic array in which the entire patterned photonic crystal region has an area smaller than 15 μm². These results provide a promising pathway toward high-performance, miniaturized lasers for photonic applications.