Light-Science & Applications最新文献

The rapid advancement of the thin-film lithium niobate (LiNbO₃) platform has established it as a premier choice for high-performance photonics integrated circuits. However, the scalability and cost-efficiency of this platform are hindered by the reliance on chip-level fabrication and integration for passive and active components, necessitating a robust wafer-level LiNbO₃ heterogeneous integration platform. Despite its critical role in enabling ultrahigh-speed optical interconnects, as well as optical mmWave/THz sensing and communication, the realization of ultrahigh-speed photodiodes and optical coherent receivers on the LiNbO₃ platform remains an unresolved challenge. This is primarily due to the challenges associated with the large-scale integration of direct-bandgap materials. To address these challenges, we have developed a scalable, high-speed InP-LiNbO₃ wafer-level heterogeneous integration platform. This platform facilitates the fabrication of ultrahigh-speed photodiodes with a bandwidth of 140 GHz, capable of receiving high-quality 100-Gbaud pulse amplitude modulation (PAM4) signals. Moreover, we demonstrate a seven-channel, single-polarization I–Q coherent receiver chip with an aggregate receiving capacity of 3.584 Tbit s^-1. This coherent receiver exhibits a balanced detection bandwidth of 60 GHz and a common mode rejection ratio (CMRR) exceeding 20 dB. It achieves receiving capacities of 600 Gbit s^-1 λ^-1 with a 100-Gbaud 64-QAM signal and 512 Gbit s^-1 λ^-1 with a 128-Gbaud 16-QAM signal. Furthermore, energy consumption as low as 9.6 fJ bit^-1 and 13.5 fJ bit^-1 is achieved for 200 Gbit s^-1 and 400 Gbit s^-1 capacities, respectively. Our work provides a viable pathway toward enabling Pbps hyperscale data center interconnects, as well as optical mmWave/THz sensing and communication.

The realization of solution-processed tandem quantum-dot LEDs (QLEDs) remains a technical challenge due to the limitations of inefficient interconnect layer and the damage caused by multiple solution processes. Here, we develop a high performance tandem QLED by face-to-face integrating a top-emitting QLED with a transparent QLED. The top and bottom units can be addressed independently, thereby enabling the tandem QLED to operate in series, parallel, and color-tunable modes for multifunctionality. In series mode, QLEDs demonstrate an ultra-low turn-on voltage of 3.3 V and a record-breaking external quantum efficiency of 60.7%. In parallel mode, QLEDs achieve an impressive brightness of over 4.8 × 10⁶cd m^-2. In color-tunable mode, the color, brightness, and color temperature can all be adjusted with a color tuning range of 114% NSTC. Moreover, both series and parallel connections contribute to an improved stability, resulting in a T₉₅ lifetime of nearly 30,000 h at 1000 cd m^-2, which is an improvement of approximately 2.8 times over control devices. Our work offers a feasible solution for achieving multifunctional tandem QLEDs with the advantages of solution processed, high efficiency, high brightness, long lifetime and full color tunability for various light source applications.

Improvements to body-surface physiological monitoring ability including real-time, accuracy and integration, are essential to meet the expansive demands for personal healthcare. As part of this, simultaneous monitoring of sweat metabolites and body temperature offers an exciting path to maximizing diagnostic precision and minimizing morbidity rates. Herein, we report a high-performance biomarker-temperature sensor made of a single As₃Se₅Te₂ chalcogenide glass fiber to monitor physiology evolution on body-surface. The sensor integrates efficient thermal resistance and fiber evanescent wave effects, permitting the independent sensing of temperature and biomarkers with an ultrahigh temperature coefficient of resistance (−5.84% K^–1), rapid temperature response (0.3 s) and excellent IR sensing sensitivity. Moreover, by attaching a fiber to the wrist, we demonstrate simultaneous observation of both sweat metabolite (urea and lactate) and temperature changes during exercise. This illuminating sensing method will provide crucial capabilities in physiological monitoring and pave the way for advanced personalized diagnostic.

The degradation caused by surface states restricts the performance of near-surface semiconductor quantum dots (QDs). Here, we demonstrate optimized passivation techniques to improve the resonance fluorescence (RF) with dot-to-dot comparisons. These optimized techniques, for the first time, reduce the linewidth and noise level of existing pulsed-RF signals, as well as revive pulsed-RF signals which originally are vanishing. The improvements are confirmed to originate from reduced surface state density and electric field after passivation, through optical and surface science characterizations. Our study promotes applications of the passivation techniques in thin-film quantum devices, paving the way for the further development of optimal QD-based quantum light sources.

Antiferromagnetism has become a promising candidate for the next generation electronic devices due to its thermal stability, low energy consumption, and fast switching speed. However, the canceling of the net magnetic moment in antiferromagnetic order presents great challenge on quantitative characterization and modulation, hindering its investigation and application. In this work, utilizing the optical second harmonic generation (SHG) in a wide temperature range, the integrated differential phase contrast scanning transmission electron microscopy, and first-principles calculations, we performed a quantitative study on the evolution of non-collinear antiferromagnetic order in BiFeO₃ films with a series of strains. We found that the antiferromagnetic coupling was significantly enhanced, featured by the increase of Néel temperature from 428 K to 646 K, and by one order of enhancement of SHG intensity contributed from the G-type antiferromagnetic order by strain manipulation from -2.4% to +0.6%. We attributed the enhancement of the antiferromagnetic coupling to the enhancement of the superexchange interaction as the Fe-O-Fe bond angle approaches 180° when the in-plane lattice constants increase, which might also result in a tendency from a non-collinear antiferromagnetic order to a collinear one. Our work not only bridges the antiferromagnetic order and the strain manipulation in epitaxial multiferroics, more importantly, also paves a way for quantitative characterization by SHG technology and the precise manipulation of antiferromagnetism.

Deterministic three-dimensional (3D) super-resolution microscopy can achieve light-matter interaction in a small volume, but usually with the axial extension distinctly more elongated than the lateral one. The isoSTED method combining two opposing objectives and multiple laser beams can offer high axial extension at λ/12 level, but at the cost of optical system complexity and inherent sidelobes. The high-order nonlinear effect by multiphoton excitation would benefit to achieve a sub-diffraction resolution as well as to suppress the sidelobes. Herein, to achieve an easy-to-use, sidelobe-free deterministic 3D nanoscopy with high axial resolution, we developed a purely physical deterministic strategy (UNEx-4Pi) by fusion of ultrahighly nonlinear excitation (UNEx) of photon avalanching nanoparticles and mirror-based bifocal vector field modulation (4Pi). The theoretical studies of UNEx-4Pi concept showed that the main peak of fluorescence spot became sharper and its large sidelobe height was suppressed with the increasing optical nonlinearity. In addition, the simplicity and robustness of UNEx-4Pi system were demonstrated utilizing a mirror-assisted single-objective bifocal self-interference strategy. Experimentally, UNEx-4Pi realized an extremely constringent focal spot without sidelobes observed, achieving an axial resolution up to λ/33 (26 nm) using one low-power CW beam. We also demonstrated the super-resolution ability of the UNEx-4Pi scheme to bioimaging and nuclear envelope of BSC-1 cells were stained and imaged at an axial resolution of 32 nm. The proposed UNEx-4Pi method will pave the way for achieving light-matter interaction in a highly confined space, thereby advancing cutting-edge technologies like deterministic super-resolution sensing, imaging, lithography, and data storage.

Accurately characterizing the intensity and duration of strong-field femtosecond pulses within the interaction volume is crucial for attosecond science. However, this remains a major bottleneck, limiting accuracy of the strong-field, and in particular, high harmonic generation experiments. We present a novel scheme for the in situ measurement and control of spatially resolved strong-field femtosecond pulse intensity and duration within the interaction focal region. Our approach combines conjugate focal imaging with in situ ion measurements using gas densities pertinent to attosecond science experiments. Independent measurements in helium and argon, accompanied by a fitting to a strong-field ionization dynamic model, yield accurate and consistent results across a wide range of gas densities and underscores the significance of double ionization, as well as barrier suppression ionization. Direct spatially resolved characterization of the driving laser is a critical step towards resolving the averaging problem in the interaction volume, paving the way for more accurate and reliable attosecond experiments.

Tailoring multiple degrees-of-freedom (DoFs) to achieve high-dimensional laser field is crucial for advancing optical technologies. While recent advancements have demonstrated the ability to manipulate a limited number of DoFs, most existing methods rely on bulky optical components or intricate systems that employ time-consuming iterative methods and, most critically, the on-demand tailoring of multiple DoFs simultaneously through a compact, single element—remains underexplored. In this study, we propose an intelligent hybrid strategy that enables the simultaneous and customizable manipulation of six DoFs: wave vector, initial phase, spatial mode, amplitude, orbital angular momentum (OAM) and spin angular momentum (SAM). Our approach advances in phase-only property, which facilitates tailoring strategy experimentally demonstrated on a compact metasurface. A fabricated sample is tailored to realize arbitrary manipulation across six DoFs, constructing a 288-dimensional space. Notably, since the OAM eigenstates constitute an infinite dimensional Hilbert space, this proposal can be further extended to even higher dimensions. Proof-of-principle experiments confirm the effectiveness in manipulation capability and dimensionality. We envision that this powerful tailoring ability offers immense potential for multifunctional photonic devices across both classical and quantum scenarios and such compactness extending the dimensional capabilities for integration on-chip requirements.

Hybrid Photovoltaic/Thermal (HPT) systems simultaneously convert solar energy into electrical power and thermal energy. These systems are attractive as they enable the thermal management of PV cells to maintain optimal operating temperatures and maximize the overall solar energy conversion. Despite their advantages, HPT systems have been limited to storing solar energy in the form of heat or simple water/space heating, thus restricting the broader application scope of HPT systems, particularly in regions with abundant solar energy. Here, we introduce a device that expands the scope of HPT applications by realizing a hybrid PV/ water desalination system, achieved through the integration of a Fano-resonant optical coating (FROC) onto a silicon substrate, which is turned superwicking via femtosecond laser surface patterning. This configuration allows a single-junction amorphous silicon solar cell to operate under higher solar concentrations with much less heat conversion, achieving a temperature reduction of 101 °C and an efficiency improvement of 335.7% compared to a standalone photovoltaic system under the solar concentration of 5. At the same time, the interfacial water desalination achieves a 2 ({kg}{m}^{-2}{h}^{-1}) high evaporation rate. Over a 12-hour cycle, our HPT system showed a consistent performance, demonstrating a combined solar conversion efficiency of 79.6%. The demonstrated superwicking-FROC will pave the way for widespread adoption of HPT systems particularly in sunny coastal regions.

An optical frequency comb comprises a cluster of equally spaced, phase-locked spectral lines. Replacing these classical components with correlated quantum light gives rise to cluster quantum frequency combs, providing abundant quantum resources for measurement-based quantum computation, and multi-user quantum networks. We propose and generate cluster quantum microcombs within an on-chip optical microresonator driven by multi-frequency lasers. Through resonantly enhanced four-wave mixing processes, continuous-variable cluster states with 60 qumodes are deterministically created. The graph structures can be programmed into one- and two-dimensional lattices by adjusting the configurations of the pump lines, which are confirmed inseparable based on the measured covariance matrices. Our work demonstrates the largest-scale cluster states with unprecedented raw squeezing levels from a photonic chip, offering a compact and scalable platform for computational and communicational tasks with quantum advantages.