Evidence for excitonic condensation and superfluidity in black phosphorus.

Excitonic condensation refers to the spontaneous formation of correlated electron-hole pairs. These collective states, also known as excitonic insulator, are expected to lead to intriguing many-body physics such as Bose-Einstein-condensates and Bardeen-Cooper-Schrieffer crossover. While the occurrence of excitonic insulator has been confirmed by measuring charge gaps, related macro-quantum phenomenon are less often observed.

Ultrabreathable Open-Cell Hierarchical Pore Structure for Radiative Cooling Protective Membranes.

Personal protective clothing is essential in biochemical threat environments, however balancing protection, thermal comfort, and breathability remains a significant challenge. This work introduces a novel, skin-friendly ultrabreathable radiative cooling protective membrane (Ub-RCPM), which is developed via a one-step evaporation-induced pore formation process. The sequential evaporation of solvent and nonsolvent during the process endows an ultrabreathable open-cell hierarchical pore structure.

Beyond Fiber: Toward Terahertz Bandwidth in Free-Space Optical Communication.

The rapid advancement of terahertz (THz) communication systems has positioned this technology as a key enabler for next-generation telecommunication networks, including 6G, secure communications, and hybrid wireless-optical systems. This review comprehensively analyzes THz communication, emphasizing its integration with free-space optical (FSO) systems to overcome conventional bandwidth limitations. While THz-FSO technology promises ultra-high data rates, it is significantly affected by atmospheric absorption, particularly absorption beyond 500 GHz, where the attenuation exceeds 100 dB/km, which severely limits its transmission range.

Decoding Fluid Flow Characteristics Through Distributed Acoustic Sensing: A Novel Approach.

Flow characteristic monitoring includes parameters such as flow regime, fluid characteristic frequency, and flow rate, which are crucial for optimizing production and ensuring the safety of oil and gas transportation systems. Existing fluid monitoring technologies, such as various flow meters, often face limitations in providing distributed and real-time monitoring data. In contrast, distributed acoustic sensing offers a spatial resolution of 1 m with high frequency sampling capability, allowing for long-term, multi-point dynamic monitoring of fluid migration characteristics.

DOF Enhanced via the Multi-Wavelength Method for the Moiré Fringe-Based Alignment.

Alignment systems are core subsystems of lithography, which directly affect the overlay accuracy of the lithography process. The Moiré fringe-based alignment method has the advantages of high precision and low complexity. However, the precision of this method is highly sensitive to variations in the gap between the wafer and the mask.

Using Higher Diffraction Orders to Improve the Accuracy and Robustness of Overlay Measurements.

This paper introduces a method for improving the measurement performance of single wavelength overlay errors by incorporating higher diffraction orders. In this method, to enhance the accuracy and robustness of overlay error detection between layers, the measurement errors introduced by empirical formulas are corrected by incorporating higher diffraction orders, based on the differences in the light intensity difference curves for different diffraction orders. This method also expands the range of available wavelengths for selection.

Design, Analysis, and Manufacturing of Diffractive Achromatic Optical Systems.

The increasing resolution requirements of imaging optical systems must be satisfied by expanding the aperture of the optical system according to Rayleigh's criterion, and larger apertures of conventional refractive/reflective optics place a greater demand on manufacturing and transportation. Diffractive optics are applied to imaging optics to achieve lightweight design, but the image quality suffers due to their strong negative properties. Therefore, a wide-band imaging system based on the Schupmann achromatic model is proposed in this paper to solve the above problem, and the achromatic performance of the system is guaranteed by the Schupmann achromatic model.

Ultrafast Hydrogen Detection System Using Vertical Thermal Conduction Structure and Neural Network Prediction Algorithm Based on Sensor Response Process.

Hydrogen detection plays a crucial role in various scenes of hydrogen energy such as hydrogen vehicles, hydrogen transportation and hydrogen storage. It is essential to develop a hydrogen detection system with ultrafast response times (<1 s) for the timely detection of hydrogen leaks. Here we report an ultrafast (0.

Nonlinear acceleration disturbance observer to reject transient peak disturbances for an inertial stabilization-tracking platform.

A high-bandwidth nonlinear acceleration disturbance observer (NOADOB) is proposed to reject transient peak disturbances mainly arising from velocity commutation of an inertial stabilization-tracking platform (ISTP). The approach is essentially based on extracting acceleration peak signals and applying a saturation function. The observer structure employs acceleration measurements and combines velocity loop input and control quantity to acquire peak signals.

Deep learning-based debris flow hazard detection and recognition system: a case study.

Debris flows are characterized by their suddenness, rapidity, large scale and destructive power, causing serious threat to the population in mountainous areas. Surveillance cameras are widely used in geological hazard monitoring and early warning projects. So far, video cameras are used as a passive tool for post inspection and not as an active role for debris flow monitoring and early warning.

Recent advances in localized surface plasmon resonance (LSPR) sensing technologies.

Localized surface plasmon resonance (LSPR) is an optical phenomenon associated with noble metal nanostructures. The resonances result in sharp spectral absorption peaks as well as enhanced local electromagnetic fields, which have been widely used in chemical and biological sensing. Over the past decade, as label-free analytical method, LSPR sensors have gained considerable interest and undergone rapid development.

Compact and aberration effects-shielded objective intraocular scatter measurement system.

The measurement of the double-pass (DP) point spread function (PSF) provides an objective, non-invasive method for estimating intraocular scatter in the human eye. In this paper, we propose a compact double-pass objective intraocular scatter measurement system that eliminates the influence of aberrations. The system includes a far-field DP PSF detection channel and a Shack-Hartmann wavefront aberration detection channel, which are used to obtain the far-field DP PSF image and 7 orders Zernike aberration coefficients, respectively.

Machining Path Optimization of Inductively Coupled Plasma Based on Surface Heat Transfer Model.

Inductively coupled plasma (ICP), a non-contact optical processing method, has been widely used in the preparation of fused quartz. However, the thermal effect during processing inevitably affects the stability of the removal rate, reduces the processing accuracy, and restricts the further development of plasma processing. This paper analyzes the critical temperature that affects the changes in plasma removal depth, establishes a heat transfer model for plasma jet processing through simulations, derives the heat conduction equation during processing, and obtains the critical radius corresponding to the critical temperature related to the processing speed.

Temperature Control of Quartz-Glass Melting Areas in Laser Additive Manufacturing.

Direct energy deposition is an additive technology that can quickly manufacture irregularly shaped quartz-glass devices. Based on this technology and coaxial laser/wire feeding, open-loop tests were conducted under different process parameters. A closed-loop temperature control system was designed and built for the molten pool temperature in quartz-glass additive manufacturing.

A Machine Vision Perspective on Droplet-Based Microfluidics.

Microfluidic droplets, with their unique properties and broad applications, are essential in in chemical, biological, and materials synthesis research. Despite the flourishing studies on artificial intelligence-accelerated microfluidics, most research efforts have focused on the upstream design phase of microfluidic systems. Generating user-desired microfluidic droplets still remains laborious, inefficient, and time-consuming.

Siamese comparative transformer-based network for unsupervised landmark detection.

Landmark detection is a common task that benefits downstream computer vision tasks. Current landmark detection algorithms often train a sophisticated image pose encoder by reconstructing the source image to identify landmarks. Although a well-trained encoder can effectively capture landmark information through image reconstruction, it overlooks the semantic relationships between landmarks.

ARSOD-YOLO: Enhancing Small Target Detection for Remote Sensing Images.

Remote sensing images play a vital role in domains including environmental monitoring, agriculture, and autonomous driving. However, the detection of targets in remote sensing images remains a challenging task. This study introduces innovative methods to enhance feature extraction, feature fusion, and model optimization.

Longitudinally continuous varying high-order cylindrical vector fields enabled by spin-decoupled metasurfaces.

The manipulation of vector optical fields in three-dimensional (3D) space plays a vital role in both fundamental research and practical implementations of polarization optics. However, existing studies mostly focus on 3D vector optical fields with limited modes. Here, an approach of spin-decoupled spatial partitioning is proposed to generate complex 3D vector optical fields with a customizable number of modes on demand.

Dynamic nonlocal metasurface for multifunctional integration via phase-change materials.

Non-local metasurface supporting geometric phases at bound states in the continuum (BIC) simultaneously enables sharp spectral resonances and spatial wavefront shaping, thus providing a diversified optical platform for multifunctional devices. However, a static nonlocal metasurface cannot manipulate multiple degrees of freedom (DOFs), making it difficult to achieve multifunctional integration and be applied in different scenarios. Here, we presented and demonstrated phase-change non-local metasurfaces that can realize dynamic manipulation of multiple DOFs including resonant frequency, values, band, and spatial wavefront.

High-resolution non-line-of-sight imaging based on liquid crystal planar optical elements.

Non-line-of-sight (NLOS) imaging aims at recovering hidden objects located beyond the traditional line of sight, with potential applications in areas such as security monitoring, search and rescue, and autonomous driving. Conventionally, NLOS imaging requires raster scanning of laser pulses and collecting the reflected photons from a relay wall. High-time-resolution detectors obtain the flight time of photons undergoing multiple scattering for image reconstruction.

Fault Tolerant Spectral/Spatial Optical Code Division Multiple Access Passive Optical Network.

High-capacity communication networks are built to provide high throughput and low latency to accommodate the growing demand for bandwidth. However, the provision of these features is subject to a robust underlying network, which can provide high capacity with maximum reliability in terms of the system's connection availability. This work optimizes an existing 2D spectral-spatial optical code division multiple access (OCDMA) passive optical network (PON) to maximize connection availability while maintaining desirable communication capacity and capital expenditure.

Measurement of ocular aberration in noise based on deep learning with a Shack-Hartmann wavefront sensor.

Shack-Hartmann-based wavefront sensing combined with deep learning, due to its fast, accurate, and large dynamic range, has been widely studied in many fields including ocular aberration measurement. Problems such as noise and corneal reflection affect the accuracy of detection in practical measuring ocular aberration systems. This paper establishes a framework comprising of a noise-added model, Hartmannograms with corneal reflections and the corneal reflection elimination algorithm.