Understanding ultrafast laser interactions with titanium alloys is critical for applications like precision machining and laser shock peening. Using a pump - probe shadowgraphy, we track the transient evolution of ablation and shock waves over delay times from 0.5 to 1600 ps. Three stages are identified: energy relaxation (0.5-1 ps), rapid material ejection (3-300 ps), and the formation of a stable ring structure after 500 ps. Ablation morphology depends strongly on laser parameters: pulse energy controls ablation diameter, while pulse duration and impact time govern depth. Shock wave expansion, propagation velocity, and pressure distribution also vary with laser settings, with the initial mechanical shock pressure up to 130.3 GPa. These results clarify ultrafast laser-matter dynamics and support optimization of laser processing parameters.

Moir & eacute; fringe imaging plays a pivotal role in high-precision measurement, anti-counterfeiting, microstructural analysis, and optical metrology. However, conventional Moir & eacute; imaging devices are typically limited to generating a single image pattern. Here, we introduce a novel multi-Moir & eacute; imaging device capable of producing images with multiple distinct patterns and varying depths of field. We first elucidate the underlying mechanisms for magnification and axial image distance in Moir & eacute; imaging, based on the fundamental principles of the Moir & eacute; phenomenon generated by the superposition of microlens arrays (MLAs) and micro-pattern arrays. MLAs with good surface morphology were then fabricated using femtosecond laser-assisted wet etching. Leveraging these imaging principles, multi-pattern and multi-depth-of-field Moir & eacute; imaging devices were successfully produced. Finally, imaging characterization of the fabricated devices confirmed their exceptional performance, demonstrating promising potential for future applications in precision measurement, anti-counterfeiting, and observation.

Electrically tunable graphene metasurfaces commonly rely on Fermi-level modulation to reshape plasmonic resonances, a process that inherently couples amplitude control to undesirable resonance-frequency shifts. This work introduces a mechanism to bypass this trade-off: field-programmed second-harmonic generation (SHG) within a spectrally stable graphene–GaN terahertz nanocavity. By applying a vertical DC field, we activate an effective second-order nonlinear response at the graphene–GaN interface through electric-field-induced second-harmonic generation. Crucially, the cavity-backed hybrid mode remains nearly invariant under bias, effectively decoupling the nonlinear source modulation from resonance-frequency tuning. Full-wave nonlinear simulations confirm electrically programmable SHG emission with minimal resonance pulling, stable near-field profiles, and multi-resonant SH spectra. This platform, leveraging multi-resonant enhancement from hybrid cavity-plasmon modes, provides a robust architecture for spectrally stable, active nonlinear terahertz metasurfaces.

ABSTRACT As a crucial part of optical systems, optical windows play an important role in medicine and industry, yet their performance is often compromised by surface contamination. Inspired by the lacrimal gland's tear storage and secretion mechanism, we propose a Lacrimal Gland‐inspired Active Replenishing Slippery Surface (ARSS) fabricated by femtosecond laser microprocessing. The surface integrates embedded storage cabins and a thermally responsive heating circuit such that localized heating creates a temperature gradient upon activation, inducing both thermal expansion of the stored silicone oil and Marangoni flow for stimulus‐responsive lubricant secretion to replenish the sliding layer. The fabricated surface exhibits high transparency exceeding 90%, excellent self‐cleaning properties against challenging pollutants including marine organisms, dust, and salt crystallization, and exceptional durability withstanding over 50 000 droplet sliding tests without performance degradation. This bioinspired design offers a long‐lasting anti‐fouling solution for optical windows, with significant potential for applications in marine engineering, biomedical devices, and other demanding environments.

This work presents a theoretical investigation into the early dynamics of ripples formation using femtosecond laser double-pulse excitation. A self-consistent multi-physics model was developed to investigate the early stage of ripples formation in highly non-equilibrium silicon. This comprehensive model accounts for the interplay between the simultaneous dynamics of optical modulation, carrier generation, and two-temperature heat transfers. We obtained the 2D dynamic evolutions of carrier density and the carrier and phonon temperatures during ripples formation induced by femtosecond laser double-pulse. The study revealed that the ripples modulation contrast of phonon temperature is significantly amplified via the second femtosecond pulse rather than the first pulse. The results are explained by the predominant enhancement of the local carrier-phonon coupling dynamics compared to the non-local dynamics of carrier ambipolar and carrier thermal diffusions following the second femtosecond pulse excitation. This study offers basic insights into the early stage of ripples formation on silicon wafers induced by femtosecond laser double-pulse, paving the way for novel surface applications in surface coloring, enhanced solar cell absorption, and surface wettability etc.

Postoperative wound management is a critical determinant of recovery in plastic surgery and burn care, where accurate assessment of wound flatness plays a central role. Yet, current evaluation remains largely subjective, relying on clinical experience rather than quantitative metrics. Here, we present a laser-microstructured piezocapacitive system: a compact, fully integrated wireless platform that is encapsulated in soft, biocompatible materials for the high-resolution, real-time monitoring of wound topography. The device incorporates a tetherless, femtosecond-laser-fabricated microstructured sensor that achieves submillimeter resolution ( < 0.1 mm) and maintains stable performance over 10 000 operation cycles. Wireless interfacing with mobile clients or server networks enables continuous evaluation of sutured wound morphology and healing progression. This platform provides objective, quantitative data on wound flatness and mechanical profiles, offering actionable metrics to guide surgical decision-making and postoperative care. By bridging a critical gap in precision wound management, this technology holds significant potential for improving clinical outcomes and standardizing quality assessment in surgical practice.

Abstract Studying various non-repeatable transient phenomena such as the transfer of photosynthetic energy and protein folding is crucial for gaining in-depth insights into multiple disciplines, while single-shot ultrafast compressed imaging provides a potent method for revealing the ultrafast dynamic process. The principle of this technology involves projecting encoded transient phenomena along a one-dimensional spatial axis onto the focal plane array and reconstructing the transient data via compressed sensing, enabling an extremely high imaging sequence depth at THz frame rates. However, this imaging method relying on single-dimensional spatial-temporal projection (SSP) suffers from severe directional constraints on reconstruction resolution, due to the suppressing of spatial features along non-projection direction. Consequently, this bottleneck seriously restricts the observation of complex transient features, hindering this technology to balance both high sequence depth and ultra-high spatial resolution. In this paper, we propose a multi-dimensional spatial-temporal projection ultrafast compressed imaging technique (MSP), which integrates multi-angle spatial-temporal data projection module into traditional SSP system. By computationally coupling projection images from both systems, MSP effectively restores omnidirectional frequency information, significantly enhancing spatial resolution. Static experiments demonstrate that both the lateral resolution and longitudinal resolution of MSP have reached 813 lp mm -1 (620 nm spatial resolution). Using MSP, we have successfully observed the transient process of femtosecond laser-material interaction with sub-micron all-directional accuracy under a 60-frame acquisition in a single-shot. MSP provides a new method for observing complex and changeable transient processes, and shows important potential in promoting the basic research of transient phenomena.

Extracorporeal membrane oxygenation (ECMO) represents the most advanced modalityof extracorporeal life support. The centrifugal pump head, a key component in direct contact with blood, demands excellent blood compatibility to ensure optimal performance. To address this requirement, a self-lubricating anticoagulant surface (SLACS) was fabricated on a roughened stainless steel substrate through physical adhesion and chemical bonding using a dimethylsiloxane gel (S-PDMS). In the blood slidingexperiment, blood remained on 316 l stainless steel for 6 s but slid off the SLACS in just 0.64 s, demonstrating exceptional resistance to blood adhesion and superior blood compatibility. Applying SLACS to the ECMO centrifugal pump head significantly enhanced its anticoagulant and antibacterial properties, while also exhibiting excellent safety, stability and durability. The feasibility of SLACS as a novel coating was validated through static tests, computational simulations and dynamic experiments, offering a promising solution for improving the safety of ECMO therapy.

Significance Hard and brittle materials (such as fused silica, sapphire, and silicon carbide) serve as core substrates in strategic fields including integrated optoelectronic devices, advanced semiconductor packaging, and extreme condition detection. The micro-hole structures of these materials are key functional units that determine device performances and application boundaries. However, traditional processing technologies have long been constrained by the trade-off between precision and efficiency: mechanical machining tends to induce cracks and subsurface damage; electrical discharge machining is only applicable to conductive materials or requires temporary conductive layers; long-pulse lasers result in obvious heat-affected zones; and focused ion beam equipment is expensive with low efficiency. Although ultrafast lasers have overcome some bottlenecks by virtue of high spatial resolution and low thermal effects, traditional Gaussian beam processing of deep holes is prone to taper formation, and thermal accumulation in multi-pulse mode easily causes microcracks. Therefore, optical field modulation technology, through the synergistic design of the spatial distribution and temporal sequence of laser energy, has become a powerful means to solve the problem of high-quality and high-efficiency micro-hole fabrication in hard and brittle materials, and is of great significance for promoting technological breakthroughs in the advanced manufacturing industry. Progress This paper systematically reviews the basic principles and latest progress of spatial modulation technology, temporal modulation technology, and spatial-temporal synergistic modulation technology in the fabrication of micro-holes in hard and brittle materials. First, spatial modulation technology focuses on the reshaping of three-dimensional energy distribution. The core of two-dimensional modulation lies in energy control perpendicular to the beam propagation direction-adjustable slits or spatial light modulators are used to improve micro-hole roundness and enable large-array parallel processing. The core of three-dimensional modulation is energy control along the beam propagation direction: optical components are used to construct long focal-depth optical fields with "non-diffractive properties", or metalenses and zone plates are employed to form optical fields with axial multi-focal energy distribution. The aspect ratio of the fabricated channels can reach 10000 (Fig. 7), and the feature size can be as small as 7 nm (Fig. 8), making it suitable for medium-to-low speed processing scenarios where high-quality micro-holes are a priority. Second, temporal modulation technology focuses on optimizing the dynamic process of energy deposition. Double-pulse modulation reduces the processing threshold through pre-ionization; the combination of long and short pulses can fabricate crack-free micro-holes with a diameter of 4 & micro;m and a length of 60 & micro;m within 2 & micro;s, while GHz pulse trains increase the ablation rate by 47% (Fig. 9). This technology is suitable for scenarios sensitive to thermal damage and requiring a certain processing speed. Finally, spatial-temporal synergistic modulation integrates the advantages of two aforementioned technologies. For example, using the temporal double-pulse Bessel beam technology, crack-free through-holes with an aspect ratio of 322 and a diameter of 3.1 & micro;m can be fabricated in 1-mm thick fused silica within only 20 mu s (Fig. 10). Synergistic modulation technology not only ensures high precision and large aspect ratio of micro-holes by virtue of spatial modulation, but also optimizes energy deposition efficiency through temporal modulation, breaking the precision and efficiency bottleneck of single modulation technology to achieve a balance between them. Furthermore, the processing capabilities of different modulation technologies are compared (Table 1), clarifying the differences in feature size, length, aspect ratio, and typical applicable materials of various technologies in micro-hole fabrication, which provides a reference for scenario-specific technology selection. Conclusions and Prospects Optical field modulation technology has established a multi-dimensional regulation system for micro-hole fabrication in hard and brittle materials. The development and coordination of different technologies have achieved further breakthroughs in micro-hole fabrication: processing efficiency has been improved rapidly, processing precision has entered the sub-10-nm level, the aspect ratio has been increased to the 104 level, and the applicable material range covers fused silica, sapphire, silicon-based semiconductors, etc. In the future, technological boundaries need to be broken through in two aspects. On the one hand, it is necessary to strengthen quantitative research on mechanisms: by combining characterization technologies such as pump-probe imaging and focused ion beam electron microscopy to establish a correlation model between optical field parameters and the processes of material electronic excitation, energy transfer, and material removal, thereby providing theoretical support for new modulation strategies. On the other hand, efforts should be made to promote industrialization implementation: improve processing efficiency and consistency by developing high-frequency response spatial light modulators and dynamic pulse energy feedback systems, achieve intelligent processing by integrating deep learning, and meanwhile develop high-precision motion control and detection systems to promote the seamless integration of optical field modulation technology with existing manufacturing systems, ultimately realizing the leap from laboratory innovation to industrial applications in fields such as advanced semiconductor packaging and biomedical detection.

High-efficiency light modulation within transparent substrates is critically important for advancing in-chip integrated optical technologies. However, current micro/nanophotonic platforms primarily rely on 2D surface configurations, rendering them inadequate for 3D optical design in dielectric environments. Here, we introduce a precise phase-transition technique that enables the direct lithography of highly regular amorphous units in multiple transparent dielectric crystals (lithium niobates, quartz, yttrium vanadate, etc.). This unit can be rapidly written with a single ultrafast laser pulse, exhibiting a high-purity amorphization phase transition interior structure and a regular sheet-like anisotropic spatial morphology (aspect ratio reaching 190:1). We reveal that this amorphization stems from ultrafast laser-driven anisotropic thermal deposition, achieved through the synergy of the light-induced high-density free electrons and thermal effects. Such embedded units achieve more than an order of magnitude improvement in the efficiency of nonlinear beam shaping (~3% second harmonic and ~0.1% third harmonic) and offer multiple degrees of freedom for device design. This study establishes a versatile platform for on-demand production of all-dielectric micro/nanophotonic architectures in the free space of transparent dielectrics, unlocking new avenues for 3D integrated photonics.

Three-dimensional (3D) microscopic imaging techniques are facing challenges to achieve greater imaging depth and enhanced visualization of results. In this paper, we propose a 3D microscope acquisition method based on a liquid lens with the translational field of view (LLTFOV). The method utilises the fast zoom function of the LLTFOV to achieve rapid depth focusing of the microscope, obtain parallax images of the specimen with complete depth information, and improve the accuracy and reliability of 3D reconstruction. By utilizing the LLTFOV's precise field of view (FOV) adjustment function, the parallax image of the specimen with multi-angle, uniform, and no vertical parallax is obtained, and the vizualisation effect of the 3D image of the specimen is improved. The 3D image of the specimen is obtained by displaying the acquired parallax synthesis image using a 3D display screen. The experimental results demonstrate that the method can efficiently reproduce the 3D images of the specimens, improving the image quality and visual experience, making it easier to obtain high-quality 3D images in scientific research and applications.

Compressed ultrafast photography (CUP) has emerged as a powerful single-shot imaging technique capable of capturing dynamic scenes with ultrahigh frame rates and large sequence depths. While providing a proven implementation platform, arising from the passive-detection mechanism of streak cameras, conventional streak-camera-only (SCO) CUP systems encounter inherent limitations in further improvement of spatiotemporal resolution and reconstructing fidelity. In recent years, significant research efforts have been directed toward all-optical and active CUP (AA-CUP) frameworks. All-optical CUP realizes temporal shearing through purely optical means, circumventing electronic dispersion limitations. Active CUP employs controlled illumination to encode temporal or spatial information prior to acquisition. These approaches have achieved breakthroughs across several key performance metrics, including tens-of-femtoseconds temporal resolution, few-mu m-scale spatial resolution, and sequence depths of approximately 1,000 frames. Aiming at solving several fundamental constraints in SCO CUP, this mini-review examines progress in AA-CUP, including the advances in temporal shearing mechanisms, compression ratio adjustments, data compression strategies, and the expansion of multifunctional imaging capabilities. The article concludes with perspectives on future research directions that aim to overcome existing limitations and expand the applicability of CUP across various scientific disciplines.

Ultrafast laser-induced micro-nano hierarchical structures show broad applicability in optoelectronics, functional surfaces, and biomedicine. However, precisely controlling their formation through light field manipulation remains a relatively unexplored area. This work demonstrates a rapid drilling strategy on silicon using an emission-programmed, high-repetition-rate femtosecond Bessel beam. This spatiotemporal modulation enables a unique manufacturing synergy that integrates subtractive drilling and thermo-fluidic redistribution by the central lobes with additive nanostructuring by the peripheral lobes, directly fabricating a micro-nano hierarchical structure comprising tapered micro-holes, elevated micropillars, and dense nanocoatings. Meanwhile, areal scanning enables programmable geometry control through line interval adjustment. This approach offers new insights into laser-matter interactions and facilitates applications in infrared photodetection or drag-reduction surfaces.

Electrochemical oxygen evolution reaction usually induces the reconstruction of NiFe layered double hydroxides (LDH) into β-Ni(Fe)OOH, which further undergoes detrimental overcharging into γ-Ni(Fe)OOH with low activity under high-potential and high-current density conditions. In this study, simultaneous reconstruction of the NiMoO4@NiFe LDH (NMO@NFL) into NiOOH@β-Ni(Fe)OOH enables maintaining the activity and stability of β-Ni(Fe)OOH. An ultralow overpotential of 203 mV is required to achieve a current density of 10 mA cm-2. In the anion exchange membrane water electrolyzer(AEMWE), a current density of 1 A cm-2 is achievable at 1.81 V. The NiOOH@β-Ni(Fe)OOH demonstrates significantly enhanced stability with a degradation rate of merely 1.86 mV h-1 at 1 A cm-2, which is over 9.5 times lower than that of the γ-Ni(Fe)OOH phase reconstructed from individual NiFe LDH (17.7 mV h-1). In situ Raman spectroscopy and density functional theory (DFT) calculation demonstrate that the heterogeneous interface effectively suppresses the overcharging of β-Ni(Fe)OOH into γ-Ni(Fe)OOH through interfacial electron donation. These findings provide crucial insights into achieving phase locking and improving stability of simultaneously reconstructed heterogeneous materials, presenting a reliable pathway for the further development of efficient and durable electrocatalysts.

Blood-contacting medical devices are essential for sustaining cardiovascular patients' lives. Advanced antithrombotic materials serve as pivotal components to enhance device reliability, as non-physiological hemodynamics and materials provoke thrombus that compromises device functionality and patient safety. Liquid-infused surfaces (LIS), as a bioinert surface modification technology, have been proven effective in inhibiting thrombus formation by suppressing the adhesion of plasma components. However, the loss of lubricants under hemodynamic shear stresses imposes limitations on their clinical application. Enhancing the durability of LIS in blood-contacting environments remains a critical challenge. Natural fluid-retentive systems, such as mucus cells, utilize secretory mechanisms and microvilli structures to anchor fluids effectively. Inspired by these biological paradigms, this study engineered a microstructured lubricant-secreting antithrombotic surface (ms-LSAS) to address the sustained antithrombogenicity requirements of medical devices. The gel-based laser-induced periodic surface structures (LIPSS) fabricated via femtosecond laser and soft lithography mitigate surface lubricant displacement caused by hemodynamic shear stress through enhanced surface area and capillary forces, while continuous secretion of the gel ensures sustained lubricant replenishment. Furthermore, the surface topographic microstructures maintain platelet adhesion suppression through steric hindrance even under lubricant-depleted conditions. Synergistic effects of the lubricating layer and flexible submicron topology suppress protein adsorption and platelet adhesion, achieving robust static and dynamic antithrombogenicity. ms-LSAS can mitigate the critical challenge in blood-contacting devices: thrombus formation induced by platelet activation on material surfaces under non-physiological hemodynamics. This bioinspired strategy may thus pave the way for achieving anticoagulation equilibrium in next-generation medical implants.

Transparent materials utilized as underwater optical windows are highly vulnerable to various forms of pollution or abrasion due to their intrinsic hydrophilic properties. This susceptibility is particularly pronounced in underwater environments where pollutants can impede the operation of these optical devices, significantly degrading or even compromising their optical properties. The glass catfish, known for its remarkable transparency in water, maintains surface cleanliness and clarity despite exposure to contaminants, impurities abrasion, and hydraulic pressure. Inspired by the glass catfish’s natural attributes, this study introduces a new solution named subaquatic abrasion-resistant and anti-fouling window (SAAW). Utilizing femtosecond laser ablation and electrodeposition, the SAAW is engineered by embedding fine metal bone structures into a transparent substrate and anti-fouling sliding layer, akin to the sturdy bones among catfish’s body. This approach significantly bolsters the window’s abrasion resistance and anti-fouling performance while maintaining high light transmittance. The sliding layer on the SAAW’s surface remarkably reduces the friction of various liquids, which is the reason that SAAW owns the great anti-fouling property. The SAAW demonstrates outstanding optical clarity even after enduring hundreds of sandpaper abrasions, attributing to the fine metal bone structures bearing all external forces and protecting the sliding layer of SAAW. Furthermore, it exhibits exceptional resistance to biological adhesion and underwater pressure. In a green algae environment, the window remains clean with minimal change in transmittance over one month. Moreover, it retains its wettability and anti-fouling properties when subjected to a depth of 30 m of underwater pressure for 30 d. Hence, the SAAW prepared by femtosecond laser ablation and electrodeposition presents a promising strategy for developing stable optical windows in liquid environments.

Single-shot ultrafast compressed imaging (UCI) is an effective tool for studying ultrafast dynamics in physics, chemistry, or material science because of its excellent high frame rate and large frame number. However, the random code (R-code) used in traditional UCI will lead to low-frequency noise covering high-frequency information due to its uneven sampling interval, which is a great challenge in the fidelity of large-frame reconstruction. Here, a high-frequency enhanced compressed active photography (H-CAP) is proposed. By uniformizing the sampling interval of R-code, H-CAP capture the ultrafast process with a random uniform sampling mode. This sampling mode makes the high-frequency sampling energy dominant, which greatly suppresses the low-frequency noise blurring caused by R-code and achieves high-frequency information of image enhanced. The superior dynamic performance and large-frame reconstruction ability of H-CAP are verified by imaging optical self-focusing effect and static object, respectively. We applied H-CAP to the spatial-temporal characterization of double-pulse induced silicon surface ablation dynamics, which is performed within 220 frames in a single-shot of 300 ps. H-CAP provides a high-fidelity imaging method for observing ultrafast unrepeatable dynamic processes with large frames.

Room-temperature Ga-based liquid metal (LM) alloys, as soft conductive materials with high liquid mobility, offer an excellent alternative for the fabrication of flexible electronics, especially in the field of flexible sensors. However, LM are highly susceptible to oxidation. The formation of an oxidized layer on the surface of LM with high adhesion will hinder continuous contact between the electrode and the dielectric layer, thus seriously affecting the stability and resulting in elevated hysteresis of sensors. Herein, a supermetalphobic dielectric layer is fabricated by femtosecond laser for an LM-based high-performance capacitive pressure sensor. Femtosecond laser-fabricated micro-nano hierarchical structures with supermetalphobicity are able to reduce the adhesion dramatically between the LM oxide layer and the dielectric layer of the sensors so that no adhesion-related damage occurs. The performance of the sensors with different dielectric layer structures has been compared by simulation and experiment. The results demonstrate that the sensor based on supermetalphobic surface exhibits significant advantages over other structures in terms of high sensitivity (1.14 kPa(-1)), excellent pressure- response stability, and low hysteresis (3.56 %). Additionally, it demonstrates a limit of detection (similar to 0.9 Pa), and rapid response and recovery time (similar to 50 ms). Moreover, the all-soft pressure sensor array was fabricated based on the micro-nano manufacturing of femtosecond laser achieving a high signal-to-noise ratio and object recognition capability.

High-density interconnect(HDI)soft electronics that can integrate multiple individual functions into one miniaturized monolithic system is promising for applications related to smart healthcare,soft robotics,and human-machine interactions.However,despite the recent advances,the development of three-dimensional(3D)soft electronics with both high resolution and high integration is still challenging because of the lack of efficient manufacturing methods to guarantee interlayer alignment of the high-density vias and reliable interlayer electrical conductivity.Here,an advanced 3D laser printing pathway,based on femtosecond laser direct writing(FLDW),is demonstrated for preparing liquid metal(LM)-based any layer HDI soft electronics.FLDW technology,with the characteristics of high spatial resolution and high precision,allows the maskless fabrication of high-resolution embedded LM microchannels and high-density vertical interconnect accesses for 3D integrated circuits.High-aspect-ratio blind/through LM microstructures are formed inside the elastomer due to the supermetalphobicity induced during laser ablation.The LM-based HDI circuit featuring high resolution(～1.5 μm)and high integration(10-layer electrical interconnection)is achieved for customized soft electronics,including various customized multilayer passive electric components,soft multilayer circuit,and cross-scale multimode sensors.The 3D laser printing method provides a versatile approach for developing chip-level soft electronics.