Monolayer molybdenum disulfide (MoS2) holds great promise for strain-tunable optoelectronic devices. The strain-dependent dielectric function is a core parameter to characterize the tunability of optoelectronic properties. However, due to the extremely short light–matter interaction path length for atomically thin materials, measurements are challenging. In this work, we measured the dielectric function of strained monolayer MoS2 using the surface plasmon resonance (SPR) method with the simulated annealing particle swarm optimization (SAPSO) algorithm. When the applied strain ranged from −0.23% (compressive strain) to +0.20% (tensile strain), the dielectric function at seven characteristic wavelengths around the exciton absorption peaks was extracted. Our results demonstrate that both the real part (ε2r) and the imaginary part (ε2i) of the dielectric function evolved almost linearly with the applied strain from −0.23% to +0.20%. Based on these results, we further obtained the strain-induced variations in the refractive index (n) and the extinction coefficient (k). At exciton absorption peak B (600 nm), the strain-induced change rate for n reached a maximum of about −0.0141%−1. At the rising edge of the B exciton absorption (580 nm), the strain-induced change rate for k reached a maximum of about −0.3261%−1. This work presents a quantitative extraction of strain-dependent dielectric function of monolayer MoS2 over excitonic band-edge wavelengths using phase SPR–SAPSO fitting. The proposed method can be extended to the measurement of other atomically thin materials.

Understanding the structural evolution during laser stealth dicing of difficult-to-process semiconductors such as AlN is crucial for wafer processing. Here, we establish a molecular dynamics model to investigate the atomic-scale evolution of AlN during laser stealth dicing and tensile fracture, and the effects of laser power, scanning duration, and scanning path on dicing performance are systematically analyzed. The results reveal that higher energy input lowers fracture stress but increases sidewall roughness. Employing sinusoidal or dual-path scanning strategies enables a reduction in fracture stress and improved defect atom distribution under the same or even reduced energy input, achieving energy-efficient, low-defect dicing. This work provides theoretical guidance for optimizing laser stealth dicing of hard materials like AlN.

High-current reliability remains a key factor hindering the commercialization of AlGaN-based deep-ultraviolet light-emitting diodes (LEDs), primarily due to elusive defect-mediated degradation. Here, we investigated the spatial distribution and nature of defects induced by high current stress in 276 nm AlGaN-based LEDs grown on high-quality AlN. The results demonstrate that the stress-induced defects are generated within the p-type layer and the active region, particularly in areas of current crowding. A combined analysis using capacitanceu2013voltage measurements, deep-level transient spectroscopy, and admittance spectroscopy reveals that p-layer degradation is driven by nitrogen vacancy (VN)-related defects originating from the dehydrogenation of hydrogen-passivated complexes. In the active region, the dominant stress-induced defects are identified as magnesium substituting gallium (MgGa), VN, gallium vacancy (VGa) complexes, and gallium-nitrogen vacancy (VGa-VN) complexes. These defects act as non-radiative recombination centers, enhancing non-radiative recombination and leading to a reduction in optical power. These findings suggest that mitigating hydrogen incorporation and optimizing current spreading are critical to high-current reliability of AlGaN-based deep-ultraviolet LEDs.

Optic-fiber-based thermal flowmeters have the merits of compact size and high sensitivity, which typically require two light beams separately acting as a pump for heating the sensing unit and a probe for sensing temperature with the variation of external flow. Here, we propose a metallic nanostructure with multiple plasmonic resonance modes for the application of an optic-fiber-based thermal flowmeter. The optical properties of a nanostructure comprised of a double-width gold grating, a poly (methylmethacrylate) (PMMA) layer, and a gold film are numerically simulated in the spectral range of 600–1800 nm. The optical resonances of different modes are systematically investigated with the variation of the structural parameters. Interestingly, two optical resonance modes with distinct spectral shift under the same temperature variation, i.e., 21.34 pm/°C vs. 269.2 pm/°C, are obtained after the strategic optimization of the nanostructure. Finally, the sensitivity of the flowmeter with the proposed nanostructure is investigated by adopting the low-temperature sensitivity mode for optical pumping and the high-temperature sensitivity mode for temperature sensing, proving its significant potential as an optic-fiber-based thermal flowmeter.

Miniaturization and multi-functionalization integration of microparticle manipulation devices remain the two major challenges in micro–nano control. Here, we demonstrate a fiber-tip photothermal microparticle controller based on asymmetric thermal effect. The fiber-tip controller is composed of an optical fiber microcavity structure and a GO+AuNBPs/PDMS composite film. The optical fiber microcavity is used to limit the spread of incident light to enhance the interaction between the optical field and the composite film and to provide real-time spectral monitoring of the thermal and deformation states of the composite film. The photothermal conversion efficiency has been enhanced significantly due to the special structure of composite film. Theory and experiments indicate that the target microparticle exhibits stable periodic oscillations and self-rotations manipulated by the controller. The oscillation frequency increased as the power of driven laser. As the power of driven laser increased exceeds 18.6 mW, the composite film undergoes irreversible deformation, which further enhances the asymmetry of the surrounding thermal field. The target microparticle would maintain stable self-rotation in asymmetric thermal field. The proposed fiber-tip controller enables the precise capture of microparticle in liquid environments, providing a reliable tool for the manipulation and selection of microparticle at a microscale.

Micronano capture systems capable of efficiently trapping target particles have been a focus in biomedical engineering, lab-on-a-chip devices, and targeted drug delivery. Here, we propose a miniature photodriven microbubble capture actuator based on an optical fiber microcavity. The actuator consists of an optical fiber microcavity and a graphene oxide/polydimethylsiloxane-gold nanobipyramids (GO/PDMS-AuNBPs) photothermal composite film. The composite film exhibits high photothermal conversion efficiency, enabling the actuator to generate a stable temperature gradient in a liquid environment. The resulting temperature gradient induces a surface tension gradient along the surface of the bubble, thereby driving the bubble toward the trapping actuator. Both theoretical analyses and experimental results confirm that the actuator successfully captures microbubbles with radii of 5 to 200 μm. Compared with conventional particle capture technologies, the proposed actuator offers several advantages, including low power consumption, a compact structural design, and high stability in liquid environments. The system provides a novel platform for biomedical applications such as live cell manipulation and microreactor construction.

The ongoing trend toward sensor miniaturization has rendered ultra-compact wafer-level vacuum packaging (WLVP) indispensable. Nevertheless, a reliable monitoring tool for wafer-level vacuum (WLV) in ultracompact devices remains unavailable. In this article, we present an ultra-compact MEMS Pirani gauge for WLV pressure monitoring. The proposed MEMS sensor is fabricated on an 8-in wafer with a footprint of 0.28 mm(2.) Experimental results demonstrate a pressure measurement range from 8 & times; 10(-2) to 10(5) Pa, with an average sensitivity of 71.812 mV/lgPa. This MEMS sensor enables in situ WLV monitoring of the sealed cavity, including the Al-Ge eutectic bonded cavity described in this study, which achieves an effective pressure of approximately 253 Pa inside the sealed cavity. Furthermore, we demonstrated the WLV monitoring of the bonded device over a period of 525 days, confirming that the adopted bonding technology maintains a vacuum level of 10(2) Pa throughout the duration. With the growing demand for high-vacuum MEMS devices, the proposed MEMS sensor shows strong potential for integration with other devices via bonding techniques, enabling in situ WLV monitoring.

Solar-driven interfacial evaporation (SDIE) is a low-energy and environmentally friendly technology for clean-water production. However, when applied to complex waters, volatile organic compounds (VOCs) can readily enter the condensate. In this study, a sequential strategy involving carbonization followed by composite fabrication was used to construct a CuO@Fe2O3@CC-SA (CFCC-SA) bimetallic oxide aerogel evaporator with both mechanical stability and flexibility for efficient water evaporation and VOC degradation. Synergistic interactions between Fe and Cu enhanced both the photothermal conversion efficiency and Fenton-like catalytic activity of the material. Meanwhile, the porous aerogel network provided excellent hydrophilicity and rapid water transport, thereby promoting efficient evaporation. Under 1.0 kW m–2 irradiation, the CFCC-SA evaporator exhibited an evaporation rate of 2.06 kg·m–2·h–1, corresponding to an approximately 20% increase relative to the monometallic CuO@CC-SA evaporator. For phenol, CFCC-SA achieved removal efficiencies of 98.4% in the condensate and 63.8% in the raffinate. Furthermore, CFCC-SA maintained high phenol removal performance over a broad pH range and under highly saline conditions (20 wt% NaCl). Overall, by integrating efficient water transport with synergistic bimetallic catalysis, the CFCC-SA evaporator offers a promising strategy for designing SDIE systems that simultaneously enable high-rate water evaporation and VOC removal.

Interfacial solar evaporation is widely used in desalination, but its application in wastewater treatment is limited by secondary contamination of the condensate by volatile organic compounds (VOCs). In this study, a BiOBr@C composite material was prepared by calcining cotton stalk pyrolysis carbon (C) with BiOBr, and a two-dimensional interfacial evaporator (BCF) was fabricated by coating the composite onto filter paper. Under 1 kW m−2 illumination, the evaporator achieved an evaporation rate of 1.94 kg·m−2·h−1 for a 20 mg/L phenol solution, while the phenol removal efficiency in the condensate reached 95%, demonstrating the successful coupling of interfacial evaporation and photocatalysis. Mechanistic analysis showed that C enhanced the solar absorption of BiOBr@C and facilitated charge-carrier separation through efficient electron transport. As a result, the catalytic activity of BiOBr@C in the phenol adsorption–degradation process was improved, and the reaction rate was approximately 1.5 times that of pure BiOBr. In addition, compared with the bulk photocatalytic mode, the BCF interfacial catalytic mode exhibited higher stability and stronger resistance to deactivation during cycling and under different environmental conditions. This study provides a new strategy for synergizing interfacial solar evaporation with photocatalysis and offers a promising solution to the secondary contamination of condensate.

This article proposes an improved frequency-shift phase-generated carrier (PGC) (Improved-FS-PGC) demodulation scheme. It aims to accurately calculate the carrier phase delay (CPD) ( theta) and modulation depth ( C) in PGC-based fiber-optic sensing systems, thereby eliminating their influence and addressing numerical singularity issues in the current methods for estimating theta and C . The approach involves using the fast Fourier transform (FFT) to extract the amplitudes of the first four harmonics from the interference signal, then constructing a new complex number by dividing adjacent harmonic amplitudes, allowing the theta to be calculated from its real and imaginary parts. After performing in-phase/quadrature (IQ) demodulation on the interference signal, FFT is applied to the demodulated result and extracts the fundamental harmonic amplitude, facilitating the determination of C while avoiding numerical singularities, such as the zeros of Bessel functions, thus extending the C range. Numerical simulations validate the algorithm's effectiveness in suppressing distortion under various conditions of theta ( -pi to pi) and C (1.5 to 7.5 rad). Experimental results demonstrate improvements in the signal-to-noise and distortion ratio (SINAD) and total harmonic distortion (THD) of 19.66 dB and 1.09%, respectively, compared to the basic frequency-shift PGC (Basic-FS-PGC). Moreover, even with variations in C and theta , THD remains below 0.37%, and SINAD exceeds 42.5 dB. Additional tests confirm the stability of this method in both time and frequency domains. This scheme provides strong support for the practical applications of fiber-optic interferometric sensors (FOISs).

BACKGROUND:Thallium, a highly toxic heavy metal, is widely distributed in the environment. The substance poses a grave threat to human health through contamination of the food chain, drinking water, and environmental exposure. Consequently, the monitoring of thallium levels, particularly in water, is of critical importance. In this study, a novel analytical method was developed for the direct quantification of thallium ions (Tl+) in aqueous samples. This method is based on the specific supramolecular interaction between cryptand[2.2.2] and Tl+, and it utilizes electrospray ionization tandem mass spectrometry (ESI-MS/MS). RESULTS:The method demonstrated remarkable analytical performance, exhibiting a linear range of 2.5 to 100 μg/L (R2 > 0.999), a limit of quantification (LOQ) of 2.5 μg/L, and a limit of detection (LOD) of 0.8 μg/L. The recovery rates exhibited a range from 88.65% to 118.09%, with relative standard deviations (RSD) falling below 10%, thereby affirming the attainment of satisfactory accuracy and precision. It is noteworthy that this method necessitated only 5 μL of sample and did not require any preliminary separation steps. Despite the inhibitory effects exhibited by complex sample matrices, these effects were effectively mitigated through a straightforward dilution strategy. The method was successfully applied to the analysis of 66 real-world environmental water samples. SIGNIFICANCE:This work presents a novel tool that enables rapid and reliable detection of Tl+ in water samples. Compared with traditional ESI methods for heavy metals, the application of cryptand[2.2.2] makes the developed method more selective and sensitive, since it has strong binding ability and selective to Tl+ ion. The study introduces a novel design concept and practical application for the development of supramolecular recognition-based ESI-MS methods for metal ion analysis. These methods hold significant potential for environmental monitoring and related fields.

In this paper, a highly sensitive dual-offset optical fiber temperature sensor based on Vernier effect is proposed. The dual-offset optical fibers (MMF1 and MMF2) are fabricated using fiber fusion technology. Both MMF1 and MMF2 have an offset size of 47 mu m, with offset lengths of 847 mu m and 533 mu m, respectively. Secondly, SU-8 photoresist is applied into the microcavity of MMF2. The photoresist is then exposed to ultraviolet light, enabling it to completely encapsulate MMF2. Incident light is split into two parts: one enters MMF1, and the other leaks into the air. The light entering the MMF1 propagates forward and is split into two beams again. One beam (I1) propagates into the SU-8 photoresist, and the other beam (I2) propagates in MMF2. Similarly, the beam leaking into the air is also split into two beams with intensities I3 and I4, respectively. I1 and I2 form the first Mach-Zehnder interferometer (MZI), and I3 and I4 form the second MZI, forming a parallel MZI. Since the free spectral ranges of the interference spectra of the two MZIs are relatively close, a Vernier envelope is obtained. In the temperature range of 30-55 degrees C, the wave node of the Vernier envelope near 1488 nm is monitored in detail. The temperature sensitivity reaches 3.2586 nm/degrees C. The proposed temperature sensor features high sensitivity, low cost, and a simple preparation process, with broad application prospects in intelligent devices, material research, and tumor therapy.

Light-driven soft actuators have attracted significant attention for applications in soft robotics. Precise quantification of the grasping force is essential for the accurate manipulation of target objects with varying mechanical properties. Here, we present a light-driven soft actuator that integrates an ultrathin tapered optical waveguide and a high-sensitivity optical fiber force-sensing probe into a graphene oxide/polydimethylsiloxane-gold nanobipyramids (GO/PDMS-AuNBPs) composite film, enabling grasping-force sensing and power-dependent actuation. The ultrathin tapered waveguide is embedded between the PDMS/GO films that provide high energy density and optical coupling efficiency. The actuator achieves a large bending angle and a fast response, reaching a bending angle of 155 degrees within 8 s. A highly sensitive optical fiber force-sensing probe with the sandwiched structure is fixed on the actuator surface to realize a wide-range force monitoring. The mechanical response of the actuator can be monitored through the integrated fiber probe and tuned by modulating the driving laser power. The proposed soft actuator was demonstrated to stably grasp and transfer lightweight targets in the milligram range under the current experimental conditions. The light-driven soft actuator integrated with an optical fiber-sensing probe offers a new perspective for the development of light-driven soft robotic systems.

Conventional ultrasonic transducers generally exhibit narrow operating bandwidths centered at specific resonance frequencies, which limit their capability for broadband ultrasonic measurements, especially in airborne or gaseous sensing scenarios. This paper presents an in-depth investigation of the ultrasonic response characteristics of a distributed Bragg reflector (DBR) fiber laser sensor. The phase shift of the fiber laser sensor induced by ultrasonic waves transmitted across a water-air interface is analyzed using mechanical-optical transformation modeling, laser wavelength shift simulation, and non-equilibrium interferometric demodulation. Both theoretical and experimental results demonstrate that the phase response has a linear relationship with the applied sound pressure across a broadband frequency range from 25 kHz to 1 MHz, with a stable and nearly frequency-independent sensitivity of approximately 0.06-0.08 rad/Pa. These results indicate that the fiber laser sensor is well-suited for broadband ultrasonic sensing, particularly in scenarios where conventional airborne ultrasonic transducers are limited. (c) 2026 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.

The development of highly efficient and stable lead-free narrow-bandgap perovskite solar cells (PSCs) is crucial for overcoming the toxicity of lead-based materials and carrier transport bottlenecks. This simulation work explores the performance potential of the narrow-bandgap Ba3SbBr3 (0.976 eV) by establishing a theoretical design paradigm via SCAPS-1D, with a focus on band engineering and defect management. A "micro-offset spike" strategy is theoretically proposed and investigated through numerical simulation, which involves engineering valence band offset (VBO) of 0.01-0.05 eV in the CuO hole transport layer (HTL) to synergistically suppress interfacial recombination and enhance hole extraction. Coupled with parabolic conduction band offset (CBO) modulation in the ZnxCd1-xS electron transport layer (ETL) - achieving a theoretically optimal CBO of 0.23 eV at 30 % Zn - and the co-optimization of Ba3SbBr3 thickness (1100 nm), NA (acceptor doping density 1 x 1018 cm-3), and asymmetric regulation of interfacial defect layers (IDLs), a maximum power conversion efficiency (PCE) of 25.39 % is predicted under idealized conditions. The simulated device is predicted to exhibit an extended infrared response up to 1270 nm (covering 43 % of the solar irradiance) and maintain PCE above 20 % over a wide temperature range of 240-420 K. This work establishes a comprehensive simulation framework, aiming to inform and accelerate subsequent experimental development of Ba3SbBr3 solar cells.

The development of perovskite solar cells (PSCs) for practical applications remains constrained by challenges in efficiency and stability. To address these limitations, a novel P-type heterojunction PSC was designed and optimized using SCAPS-1D. This fully inorganic device, which omits a hole transport layer, exhibits high stability. Its architecture combines CsPbIBr2 as the primary absorber layer with CsGeI3 as a secondary layer. The resulting built-in electric field enhances carrier transport and extends light absorption across the visible spectrum, improving overall photon utilization. By systematically varying absorber layer thickness, doping concentration, and defect density, the simulation examined their effects on light absorption, energy band bending, and SRH recombination rates. In addition, careful selection of the electron transport layer (ETL) and metal work functions further optimized device performance. The resulting PSC achieved a maximum power conversion efficiency (PCE) of 30.13 % with a fill factor (FF) of 85.14 % under ideal conditions, and retained a PCE of 26.63 % with an FF of 81.74 % under practical conditions, significantly surpassing single-layer PSC designs. These results demonstrate the potential of P-type heterojunction lead-germanium PSCs for optoelectronic applications and provide a theoretical framework for developing high-efficiency, stable, and cost-effective devices.

We investigated the effects of gamma (γ) ray irradiation on 255 nm AlGaN UV LEDs under various stress conditions, including current stress and combined irradiation and current stress. Our results show that the LEDs are similarly impacted by all conditions, with powered devices exhibiting significant changes in both optical and electrical properties. Deep Level Transient Spectroscopy (DLTS) was used to analyze defects, revealing that γ-ray exposure and other stresses primarily affect the active region and p-side of the device. The observed effects are attributed to an increase in hole traps associated with gallium vacancy complexes at 0.67 eV and nitrogen vacancies associated with active regions (VN traps) at 0.2 eV. These defect concentrations alter the effective carrier concentration, accelerating degradation under electrical stress. Our findings provide new insights into the radiation tolerance of 255 nm AlGaN UV LEDs under various stress conditions.

Developing complementary metal oxide semiconductor (CMOS) integrated circuits (ICs) combining high flexibility and ultrastrong radiation tolerance features will expand conventional chips into ever-increasing extreme applications. Here, we develop a technology to fabricate flexible CMOS field-effect transistors (FETs) and ICs with ultrastrong radiation tolerance based on a semiconducting carbon nanotube (CNT) film via a system technology co-optimization strategy encompassing materials, fabrication process, device structure, circuit architecture, and passivation/encapsulation. The fabricated CNT CMOS FETs exhibit high and symmetric performances, excellent flexibility, and especially recorded radiation tolerance to total ionizing doses up to 24 Mrad (Si), and then flexible and strong radiation-tolerant ICs including inverters, ring oscillators, and static random-access memory cells have been demonstrated. Notably, high-energy irradiation introduces two competing effects where it causes damage but also reduces gate interface state density to improve the performance of the ICs. These findings position flexible CNT CMOS technology as a promising candidate for use in electronics in extreme environments.

The development of bio-inspired neural systems has emerged as a transformative approach to overcome the limitations of von Neumann architecture, replicating the remarkable energy efficiency and unified sensory-processing capabilities of biological neurons. In this work, we present a monolithic neuromorphic platform utilizing cascaded single-walled carbon nanotube thin-film transistors (SWCNT TFTs) that integrate Mini-light-emitting diodes (Mini-LEDs) with optoelectronic synaptic transistors, achieving synergistic optoelectronic integration. The SWCNT TFTs exhibit dual functionality: (1) as highly stable active-matrix drivers (>1 000 operational cycles) enabling precise Mini-LED grayscale modulation, and (2) as efficient optoelectronic synaptic devices. Fabricated at wafer-scale with micrometer feature sizes, these devices demonstrate exceptional performance metrics, including low operating voltages (±1 V), high on/off ratios (10⁶), near-ideal subthreshold swing (78 mV·dec ^−1 ), and precise Mini-LED current regulation (10 ^− ⁸ A–10 ^− ⁴ A) under 25 Hz pulsed gate operation. The optoelectronic synaptic devices based on organic-semiconductor heterojunction formed between poly (3,3’’’-didodecyl quaterthiophene) (PQT-12) and semiconducting SWCNTs enable broadband photoresponses (365 nm–710 nm) through efficient charge transport, driven by TFT-controlled Mini-LED pulses. The implemented bio-inspired visual system successfully emulates fundamental synaptic functionalities, exhibiting excitatory postsynaptic currents (EPSC), short-term potentiation (STP), and long-term potentiation (LTP). Notably, we demonstrate system-level functionality through a five-layer convolutional neural network, achieving 92.02% accuracy on MNIST classification, while the monolithic integration establishes a biomimetic closed-loop “electrical-optical-electrical” pathway that faithfully simulates complete biological synaptic operation. This pioneering cascade of electronic, photonic, and optoelectronic components represents a significant advancement toward high-density, energy-efficient neuromorphic computing.