Laser

arXiv:2603.22034v1 Announce Type: new Abstract: Nanoscale control of optical dispersion is essential for applications ranging from miniaturized spectrometers to color printing, all of which demand broadband spectral tunability. However, the Kramers-Kronig relations impose a fundamental trade-off between dispersion and loss, strictly limiting the design ability of single-material devices across the deep ultraviolet (DUV) to near-infrared (NIR) regimes. Consequently, the fabrication of miniaturized dispersion devices heavily relies on costly nanofabrication or heterogeneous integration. Here we overcome these limitations by shifting the light-matter interaction from solid structure into air-filled voids. We introduce a fabrication strategy termed "Mie-lithography", in which laser printed seed nanocavities excite Mie resonances in air and the resulting localized field enhancement drives the self-assembly of three-dimensionally tunable void-type optical resonators. Because the resonant

arXiv:2603.22025v1 Announce Type: new Abstract: Photon superbunching, distinguished by second-order coherence values far exceeding the Gaussian thermal limit, represents a highly desirable resource for quantum optics and correlation-based imaging technologies. However, existing approaches typically rely on fragile experimental platforms, inefficient nonlinear conversion processes, or mechanically complex optical architectures. Here, we demonstrate a fully fiber-integrated superbunched random fiber laser (SRFL) in which intrinsic Rayleigh scattering cooperatively interacts with cascaded stimulated Brillouin scattering and quasi-phase-matched four-wave mixing to tailor extreme photon statistics. The SRFL generates a multi-wavelength comb, in which individual spectral components exhibit widely tunable photon bunching, with the second-order coherence g(2)(0) continuously controlled from ~1 to ~26 by tuning the pump power, spectral order and diffusion length. Moreover, we establish a

arXiv:2603.21998v1 Announce Type: new Abstract: Femtosecond laser micromachining (FLM) fabricated waveguides inherently form elliptical cores due to differences in focal spot size and the Rayleigh range of the microscope objective. Consequently, it is essential to study their propagation characteristics, which differ from those of conventional circular-core waveguides. In this work, we present the results of a parametric optimization of these waveguides to identify fabrication parameters that lead to minimal loss. A propagation loss characterization study revealed that, for a laser wavelength of 1030 nm, a pulse width of $\sim$300 fs, a pulse energy of 600 nJ, a scan speed of 2 mm/s, and a repetition rate of 100 kHz, a transparent and micro-bubble-free waveguide with a propagation loss of $\sim$0.4 dB/cm was formed. The modal analysis further demonstrated that the V-number depends on the core aspect ratio. The waveguide modes were compared with computationally generated modes,

arXiv:2603.21798v1 Announce Type: new Abstract: In the present study, wakefield amplification via coherent resonant excitation using two co propagating laser pulses in a homogeneous plasma is investigated. The proposed scheme is based on linearly polarized leading seed pulse followed by a trailing pulse with identical or controlled parameters, enabling phase synchronized energy transfer to the plasma wave. By systematically varying the temporal pulse widths and inter pulse separation, conditions for resonant enhancement of the wakefield are established. Analytical modelling, supported by particle in cell simulations, reveals that maximum amplification occurs when the pulse separation approaches a quarter of the plasma wavelength, ensuring constructive interference of the plasma oscillations driven by successive pulses. Under optimal conditions, the coherent resonant excitation leads to a significant enhancement of the wakefield amplitude, reaching up to three times of that produced by

arXiv:2603.20952v1 Announce Type: new Abstract: We report on a novel type of dual-wavelength fiber laser with a structured-core design inside silica glass, forming a spatial separation of the several core areas doped with ytterbium and erbium ions. We have optimised the key parameters of the fiber core, such as the concentration of rare earth elements, and the optimal length of active fiber to operate simultaneously at two different wavelengths. Using the Modified Chemical Vapor Deposition method to obtain initial optical fiber preforms, and using the stack and draw technique, we have fabricated two types of active fibers, one with 7 and one with 19 rare-earth-doped rods (elements) forming the fiber core. We characterized the drawn fibers by investigating their structure by scanning electron microscopy, confirming the spatial separation of the elements within the core. Measuring absorption shows that concentration ratios Nt Yb: Nt Er were approximately 52: 48 for 7 core fibers and

arXiv:2603.20916v1 Announce Type: new Abstract: Plasma-based mid-infrared (MIR) laser generation has garnered significant interest owing to its advantage of high output power, continuous wavelength tunability, and ultrashort pulse durations. However, existing methodologies predominantly depend on high-intensity inputs at the hertz frequency level, with spectral energy concentrated near the central frequency, rendering them unsuitable for spectroscopic applications. This paper proposes and demonstrates a cascaded deceleration scheme that enables the generation of broadband MIR lasers with low energy inputs compatible with high-repetition-rate laser systems. By confining the input laser within a plasma channel, this approach preserves the laser intensity, which not only sustains the decelerating field strength but also enables the cumulative effect of deceleration across multiple distinct bubbles. Numerical simulations demonstrate that more than 30% of the 23 mJ input energy is

arXiv:2603.20832v1 Announce Type: new Abstract: Laser-driven ion acceleration from nanostructured targets offers a promising route to compact, high-energy ion sources. In this work, we demonstrate through particle-in-cell simulations that rectangular nanoring targets significantly enhance energy absorption and increase the cutoff energy of laser-accelerated ions. The nanoring geometry enables strong field confinement within its hollow core when optimally oriented relative to the laser polarization, leading to hotter electron populations and more robust sheath acceleration. These results demonstrate that rectangular nanorings offer a versatile platform for controlling laser-plasma interactions at solid densities and advancing compact, high-repetition-rate particle sources.

arXiv:2603.20565v1 Announce Type: new Abstract: Direct laser acceleration (DLA) enables energy transfer from an ultra-high-intensity laser to plasma electrons and underpins many laser-driven particle and radiation-source concepts. A laser-driven azimuthal plasma magnetic field is a key player in this process: it confines energetic electrons, induces betatron oscillations, and makes possible a resonant interaction between the betatron motion and the laser field. While this betatron resonance can enhance electron energy gain, the gain itself generally drives frequency detuning and promotes largely reversible energy exchange that limits net acceleration. Here we show, using a test-electron model with prescribed fields, that a slow longitudinal increase of the quasi-static plasma magnetic field qualitatively changes DLA by introducing hysteresis in the ratio of the betatron frequency to the laser frequency experienced by the electron, so that this ratio depends on the prior evolution of

arXiv:2603.20577v1 Announce Type: new Abstract: Automating large-scale manufacturing in domains like timber construction requires multi-robot systems to manage tightly coupled spatiotemporal constraints, such as collision avoidance and process-driven deadlines. This paper introduces LASER (Level-based Asynchronous Scheduling and Execution Regime), a complete framework for scheduling and executing complex assembly tasks, demonstrated on a screw-press gluing application for timber slab manufacturing. Our central contribution is to integrate a barrier-based mechanism into a constraint programming (CP) scheduling formulation that partitions tasks into spatiotemporally disjoint sets, which we define as levels. This structure enables robots to execute tasks in parallel and asynchronously within a level, synchronizing only at level barriers, which guarantees collision-free operation by construction and provides robustness to timing uncertainties. To solve this formulation for large problems,

arXiv:2603.19916v1 Announce Type: new Abstract: Structured-core thulium-doped fibers were developed to reduce heat load, enable shorter-wavelength operation, and achieve a pedestal-free design. In a proof-of-principle experiment, laser slope efficiencies of 52% at 1907 nm and 54% at 1940 nm were achieved with respect to absorbed power.

arXiv:2603.19811v1 Announce Type: new Abstract: Devices employing cryptographic approaches have to be resistant to physical attacks. Side-Channel Analysis (SCA) and Fault Injection (FI) attacks are frequently used to reveal cryptographic keys. In this paper, we present a combined SCA and laser illumination attack against an Elliptic Curve Scalar Multiplication accelerator using a differential probe from Teledyne LeCroy. Our experiments show that laser illumination increases the power consumption of the chip, especially its static power consumption but the success of the horizontal power analysis attacks was changed insignificantly. We assume that using a laser with a high laser beam power and concentrating on measuring and analysing only static current can improve the attack success significantly. The horizontal attacks against public key cryptosystems exploiting the Static Consumption under Laser Illumination (SCuLI attacks) are novel and their potential is not investigated yet.

arXiv:2603.18931v1 Announce Type: new Abstract: Self-generated magnetic fields are commonly produced in high-power laser-plasma interactions. These fields can inhibit plasma heat-flow which makes them important in inertial fusion and controlled laboratory astrophysics experiments. In this work, we characterize the time evolution of self-generated magnetic fields using multi-view proton tomography at two timings. Tomographic reconstructions of the magnetic field show a clear transition from fields located close to the target at early time to more extended coronal fields at later time. The tomographic inversion and mesh radiography also enable a direct measurement of the magnetic-flux evolution. Comparisons with extended-MHD simulations show only moderate agreement in field structure, but good agreement in magnetic flux. This suggests that the field generation model is largely correct under these conditions, while the magnetic transport model requires additional development to reproduce

arXiv:2603.18518v1 Announce Type: new Abstract: Randomness in optical systems emerges as a powerful resource for generating complex, non-deterministic light-matter interactions. In particular, random plasmonic metasurfaces harness nanoscale disorder to produce unique and irreproducible optical responses, positioning them as an ideal platform for physical unclonable function in secure optical authentication. However, realizing such random metasurfaces in a rapid, scalable, and chemical-free manner for optical PUFs remains challenging. Here, we introduce a nanosecond pulsed laser scribing method for one-step fabrication of a robust random plasmonic metasurface physical unclonable function. By delivering spatially localized, ultrafast energy bursts, this technique harnesses naturally occurring instability to generate stochastic plasmonic nanostructures in nanoseconds. The unique plasmonic metasurfaces are effectively transformed into a macroscopic, non-replicable optical fingerprint via

arXiv:2603.17700v1 Announce Type: new Abstract: The development of high-power single crystal fiber (SCF) lasers is critically hindered by the lack of a reliable cladding scheme to confine the optical mode and ensure beam quality. Here, we propose and demonstrate a two-step tapering-collapse method for the first time to fabricate a high-quality cladding on Yb:YAG SCFs based on elemental interdiffusion. This in-situ formed crystalline transition layer with a graded refractive index effectively suppresses lattice mismatch and abruptly mitigates core-cladding interfacial stress. Consequently, the numerical aperture of the SCF is significantly reduced from 0.280 to 0.199. In a master oscillator power amplifier configuration, the clad SCF delivers a remarkable 46.7% enhancement in slope efficiency compared to its bare counterpart, accompanied by a substantially improved near-field beam profile. This work establishes a facile and effective route to high-performance clad SCFs, unlocking their

arXiv:2603.17697v1 Announce Type: new Abstract: Robust laser delivery and stabilization are key components in atom-based quantum technologies, such as quantum computing. Moving these technologies towards product-like deployment requires scalable, compact, cost-effective, and upgradable modules. Here we describe laser systems consisting of application-flexible modules, and demonstrate their performance by characterizing key metrics and by integration with ion trap systems. The laser system is confined to a single server rack and a compact locking station. Both are Class 1 laser products with fiber in-out and electronic control of the laser light. This is achieved through precision manufacture of optical boards that are designed to reduce the degrees of freedom, ease alignment, and increase the robustness to environmental factors. We present a range of 13 wavelengths from 375 nm to 1092 nm: efficiencies from laser source to ion trap range from 21 - 28%, with laser stabilization line

arXiv:2603.17203v1 Announce Type: new Abstract: We present a computational study of the laser-driven quantum dynamics of positronium (Ps), PsH, and PsCl at the time-dependent Hartree-Fock level of theory. To eliminate finite-basis effects and to properly capture continuum dynamics, we use a spherical polar pseudospectral representation. The multicomponent theory and its implementation are described in detail. We find that while the presence of the positron delays electron ionization in PsH, a slight enhancement of electron ionization is observed in PsCl. In both cases, the positronic response is faster than that of the electrons. We propose that the formation of PsCl may be directly observed through photopositron spectra in the multiphoton regime, where PsCl peaks are expected at roughly twice the energy of Ps peaks, making PsCl clearly distuinguishable from Ps. In the tunelling regime, however, photopositron rescattering peaks may only be distuinguishable if the amount of Ps is

arXiv:2603.17164v1 Announce Type: new Abstract: We demonstrate efficient diffraction of intense ultrashort laser pulses using optical field ionization plasma-neutral gratings formed by spatially patterned gas ionization in the interference field of two femtosecond pump pulses. The resulting transient refractive index modulation is shown to be persistent over tens of picoseconds at a 10 Hz repetition rate. An intense femtosecond signal pulse is diffracted by the plasma structure with an average single-order efficiency of up to 35$\%$ at intensities exceeding $ 10^{14}\text{ W/cm}^2$. The diffraction efficiency increases with pump energy, scales with grating aperture, and is optimized at a specific grating length in agreement with coupled-mode theory for periodic media. These results demonstrate the scalability and high damage threshold of photonic plasma structures crucial for controlling ultrashort intense laser beams, with potential applicability to multi-petawatt systems.

arXiv:2603.17127v1 Announce Type: new Abstract: We propose and simulate a laboratory platform to study the effects of positrons in magnetic reconnection using laser-driven capacitor coils. Using particle-in-cell simulations, we show that externally injected MeV electron-positron pairs are trapped in the coil current sheet, significantly modifying the reconnection dynamics and particle acceleration. These pairs increase the reconnection rate by a factor of approximately 8, which Ohm's law decomposition reveals to be driven by the divergence of the generalized pressure tensor. Based on their high energy and magnetization, the pairs also substantially broaden the diffusion region. Particle tracking simulations in realistic coil magnetic fields further demonstrate that injected pairs can remain confined for several picoseconds, providing conditions for sustained interaction with the reconnection region. These results establish a near-term pathway to laboratory studies of

arXiv:2603.15808v1 Announce Type: cross Abstract: Axions are hypothetical particles, proposed to account for the invariance of CP symmetry in quantum chromodynamics. While axions and axion-like-particles are well-motivated by string theory and beyond-Standard-Model extensions, they have remained elusive to experimental searches even after significant effort over many decades. Building on a recent development using an X-ray free electron laser to search for cosmologically favoured axions of mass $m_{a} \lesssim 0.01$ eV, we extend previous bounds on the ALP-photon coupling, $g_{a\gamma\gamma}$, by over an order of magnitude. We exploit the Bormann effect of Laue crystals in a light-shining-through-wall experiment, with broad sensitivity to $m_a \lesssim$ 22 eV. Moreover for $m_{a} \in$ (3460, 3480) eV our sensitivity reaches down to the QCD axion coupling prediction, providing the most stringent laboratory constraints in this mass range.

arXiv:2603.15996v1 Announce Type: new Abstract: Leveraging the full scientific capabilities of next-generation high-repetition-rate free-electron lasers requires programmable control over electron-beam properties at their source. The photoinjector drive laser defines the electron beam's initial six-dimensional phase-space distribution, yet has historically been limited to Gaussian or static flat-top profiles, with most manipulation occurring downstream. Here we demonstrate software-programmable ultraviolet pulse shaping at the LCLS-II photoinjector as a source-level actuator that complements traditional accelerator controls. Using a coupled architecture combining dispersion-controlled nonlinear frequency conversion with spatial-light-modulator spectral shaping, we generate user-defined temporal structures and observe their imprint on electron bunches through high-resolution time-domain diagnostics. Laser-imposed multi-peaked modulation persists through acceleration, magnetic

A new laser range-finding technique, inspired by quantum physics, that can measure distances under strong solar background has been demonstrated by researchers at the University of Bristol. The team has proved their hypothesis by testing out their new method on some of the university's most iconic buildings.

For the first time, a quantum radiation reaction in strong electromagnetic fields has been demonstrated experimentally by allowing electrons to collide with an extremely intense and powerful laser beam. The research findings provide insights needed for new quantum-mechanical computational models and clues to how the laws of physics operate near neutron stars or black holes.

The controlled generation of single photons is an essential element of numerous quantum technology applications, such as quantum networks and quantum computing. A research team has now demonstrated the successful application of the new SUPER (Swing-UP of the quantum EmitteR population) method. The approach facilitates the controlled generation of light particles (photons). Results of the study were recently published in the journal Nature Communications.

arXiv:2603.15533v1 Announce Type: new Abstract: Molecules containing short-lived isotopes, namely radioactive molecules, are among the most promising candidates for probing new physics beyond the Standard Model, although their production and spectroscopic measurements remain technically challenging. Here, we demonstrate an integrated methodology that combines formation of molecular ion beams in a radiofrequency quadrupole cooler-buncher with collinear laser spectroscopy. As a proof-of-principle experiment, we successfully produce molecular ions such as $\rm BaF^+$ and $\rm YbF^+$ via in-trap ion-molecule reactions and perform high-resolution laser spectroscopy of the target molecule $\rm ^{138}BaF$. Vibrational and rotational structures of $\rm ^{138}BaF$ across different electronic states are obtained using resonance-enhanced multiphoton ionization schemes, confirming the feasibility of the proposed methodology. This work establishes a practical route for future formation and

arXiv:2603.15476v1 Announce Type: new Abstract: Stimulated Brillouin and Raman scattering (SBS and SRS) are instabilities that affect the propagation of high-power lasers in plasmas. The latter is further affected by Cross-Talk (CT) effects when multiple laser beams are simultaneously propagated in the plasma, as found in the schemes proposed for inertial confinement fusion (ICF). Here we develop a new theoretical model that allows us to evaluate the impact of CT on SBS and SRS in low-density plasmas. As supported by experiments, we demonstrate that CT can lead to a reduction of both SBS and SRS, due to the destabilization of the individually triggered instabilities. We further demonstrate that this destabilization effect is accelerated by applying an externally magnetic field to the plasma, which is also beneficial for the hydrodynamics or fuel heating of ICF. By shedding new light on the promising scheme of magnetized ICF, our findings thus offer beneficial prospects for ICF.

arXiv:2603.15407v1 Announce Type: new Abstract: Free-electron lasers (FELs) generate the brightest coherent X-ray pulses available, enabling atomic-resolution and femtosecond-timescale studies across physics, chemistry, and biology. Realising their full potential at extreme peak powers and attosecond pulse durations critically depends on sustaining coherent gain across the full bunch length. Yet, the quasi-static longitudinal space-charge field in the ultrahigh-current regime imprints a slice-dependent energy detuning that quenches gain growth, so that current schemes typically sustain efficient lasing only across a limited fraction of the bunch. Here we demonstrate that a quasi-neutral electron-positron pair beam cancels this self-field and enables full-bunch high-gain lasing in ultracompressed beams without external compensation. Three-dimensional particle-in-cell simulations in a single-pass, untapered undulator confirm the mechanism across operating regimes: in the soft X-ray

arXiv:2603.14391v1 Announce Type: new Abstract: Advancing additive manufacturing, e.g., laser powder-bed fusion (LPBF), requires resolving rapid processes such as melt-pool dynamics and keyhole evolution in 4D (3D + time). Operando X-ray tomography is a state-of-the-art approach for 4D characterization, but its temporal resolution is fundamentally constrained by the sample rotation speed, limiting achievable 4D imaging rates and preventing the resolution of these fast phenomena. Here we present rotation-enabled X-ray Multi-Projection Imaging (rotation-XMPI), which captures three angularly resolved projections per time step and thereby decouples temporal resolution from the sample rotation speed. Combined with a self-supervised deep-learning reconstruction framework for multi-angle inputs, rotation-XMPI enables high-fidelity 4D imaging at unprecedented speed. We demonstrate the approach in an operando alumina laser-remelting experiment at MAX IV using three beamlets combined with 25 Hz

arXiv:2603.14063v1 Announce Type: new Abstract: The phenomenon of electron-laser vacuum breakdown is the multiple cascade production of electron-positron pairs in head-on collision of a beam of relativistic electrons with an intense laser pulse. This effect was first predicted by the author in 1996 [1] and further developed in [2]. In the present paper, an analytical expression for the total number of produced particles is obtained using the generalized Heitler model. The model results are shown to be in good agreement with the estimates of the pioneering works. An analysis of modern laser facilities (ELI, XCELS, European XFEL, Russian projects) is carried out and estimates of the expected effects are given. At ELI and XCELS class facilities, the quantum nonlinearity parameter can reach 60--150, corresponding to the deeply nonlinear QED regime with multiplicity up to 100 particles per seed electron. Experimental confirmation of the effect is expected in the coming years.

Researchers from Tokyo Metropolitan University have succeeded in detecting laser-assisted electron scattering (LAES) using circularly polarized light for the first time. The use of circularly polarized light promises valuable insights into how atomic scale "helicity" impacts how electrons interact with matter and light.

The High Energy Laser with Integrated Optical-dazzler and Surveillance, deployed on a US naval ship, downed several drones last week. Here’s what you need to know about the game-changing technology.

Physicists have detected laser-assisted electron scattering using circularly polarized light for the first time, revealing new ways to probe atomic-scale chirality.

arXiv:2603.11980v1 Announce Type: new Abstract: In this paper, we study multi robot laser tag, a simplified yet practical shooting-game-style task. Classic modular approaches on these tasks face challenges such as limited observability and reliance on depth mapping and inter robot communication. To overcome these issues, we present an end-to-end visuomotor policy that maps images directly to robot actions. We train a high performing teacher policy with multi agent reinforcement learning and distill its knowledge into a vision-based student policy. Technical designs, including a permutation-invariant feature extractor and depth heatmap input, improve performance over standard architectures. Our policy outperforms classic methods by 16.7% in hitting accuracy and 6% in collision avoidance, and is successfully deployed on real robots. Code will be released publicly.

arXiv:2603.11252v1 Announce Type: new Abstract: Although semantic 3D city models are internationally available and becoming increasingly detailed, the incorporation of material information remains largely untapped. However, a structured representation of materials and their physical properties could substantially broaden the application spectrum and analytical capabilities for urban digital twins. At the same time, the growing number of repeated mobile laser scans of cities and their street spaces yields a wealth of observations influenced by the material characteristics of the corresponding surfaces. To leverage this information, we propose radiometric fingerprints of object surfaces by grouping LiDAR observations reflected from the same semantic object under varying distances, incident angles, environmental conditions, sensors, and scanning campaigns. Our study demonstrates how 312.4 million individual beams acquired across four campaigns using five LiDAR sensors on the Audi

arXiv:2603.10257v1 Announce Type: cross Abstract: Solid-state semiconductor lasers underpin technologies from telecommunications and data storage to sensing, medical diagnostics, and emerging quantum communication. Polaritons-hybrid exciton-photon states have further extended this reach, enabling room-temperature quantum effects such as low-threshold lasing and single-photon nonlinearities. Organic semiconductors are ideal for polaritonics due to their large exciton binding energy, strong optical nonlinearities, and straightforward processing, making them attractive for both classical and quantum photonics. While solution-processed organic films have been widely explored, their optical cavities have almost always been fabricated using vacuum deposition, limiting the realization of truly scalable and low-cost devices. Here, we report the first organic laser microcavities fabricated entirely by solution processing, which operate in the strong coupling regimeThe resulting platform can be

arXiv:2603.10630v1 Announce Type: new Abstract: We report laser cooling of Yb3+-doped KY3F10 (Yb:KY3F10) driven by a 100-W, 1020-nm pump source. Despite pumping at a non-optimal wavelength, high-quality KY3F10 crystals doped with 3% and 7% Yb were cooled to 145 K and 151 K, respectively, in a double-pass pump configuration. These results establish Yb:KY3F10 as an attractive laser-cooling medium competitive with Yb:YLF, the state-of-the-art laser-cooling material for optical cryocoolers. The observed cooling performance and spectroscopic characteristics suggest that lower cryogenic temperatures may be achieved through pump-wavelength optimization, enhanced pump absorption, and reduced radiative heating.

arXiv:2603.10058v1 Announce Type: new Abstract: We report the first in-air irradiations of biological samples with kHz laser-driven electrons with beam energy 20 MeV, high-energy tail extending to 40 MeV, and average dose rate up to 30 Gy/min. An in-house procedure has been developed to characterize and deliver on-demand (i.e. pre-agreed date and time) the target electron beam energy, dose and dose uniformity. We present a tolerance analysis on the laser electron parameters, highlighting the importance of beam stability for precise irradiations of in vivo zebrafish embryos and in vitro U251 glioblastoma cell line. The observed improvement in the survival rate of the zebrafish embryos, combined with unchanged cytotoxicity in the cell cultures, indicates promising results for normal tissue sparing while maintaining anticancer efficacy. The pre-clinical results of this work represent an important milestone towards the clinical translation of laser-plasma accelerators.

Researchers at DTU have developed a groundbreaking nanolaser that could be the key to much faster and much

Physicists have demonstrated a new kind of vacuum ultraviolet laser that is 100 to 1,000 times more efficient than existing technologies of its kind.

Physicists at the University of Colorado Boulder have demonstrated a new kind of vacuum ultraviolet laser that is 100 to 1,000 times more efficient than existing technologies of its kind. The researchers say the device could one day allow scientists to observe phenomena currently out of reach for even the most powerful microscopes—such as following fuel molecules in real time as they undergo combustion, spotting incredibly small defects in nanoelectronics and more.

arXiv:2603.09871v1 Announce Type: cross Abstract: Direct laser writing of ferromagnetic microstructures is of great interest for sensing and data storage in compact three-dimensional architectures. However, reliable direct laser writing of metallic and even more so ferromagnetic materials remains a major challenge. Here, we present a novel photoresist suitable to direct laser write ferromagnetic nickel based on sensitized triplet-triplet annihilation upconversion. By combining an in-situ photochemical deoxygenation process with a sensitized triplet-triplet annihilation upconversion process as well as a photoreduction of Ni2+ ions, the deposition of metallic nickel is enabled under ambient conditions. Using this approach, nickel structures are fabricated as a proof of concept. Scanning electron microscopy and EDX analysis confirm the spatially confined deposition of nickel, while magnetic characterization by vibrating sample magnetometry and scanning NV magnetometry demonstrate the

arXiv:2603.09064v1 Announce Type: new Abstract: We systematically investigate the field-aligned propagation and collisional absorption of normally incident laser light in a strongly magnetized inhomogeneous plasma. Analytical expressions for electric fields in both vacuum and plasma are derived. Using analytical modelling and particle-in-cell simulations, we establish the cutoff conditions, absorption efficiencies, and scaling laws for the right-hand (R) and left-hand (L) circularly polarized waves. The dependence of collisional absorption coefficient on magnetic field strength, plasma scale length and laser intensity are quantified. In particular, L waves reflect at cutoff density, with absorption strongly enhanced as the magnetic field increases. For the R-waves, the absorption decreases with increasing magnetic field when the normalized electron cyclotron frequency is less than unity. However, when it exceeds unity, the R-waves propagate as whistler modes without a cutoff, allowing

A research team at Chalmers University of Technology, Sweden, has developed new laser technology that could lead to tiny, cost-effective biosensors.

A research team at Chalmers University of Technology, Sweden, has developed new laser technology that could lead to tiny, cost-effective biosensors. The sensors integrate lasers and optics together on a centimeter-sized chip, which could move testing from hospitals to patients' homes. This, in turn, would free up hospital beds and reduce visits to clinics.

arXiv:2603.07967v1 Announce Type: cross Abstract: The spaceborne laser emission telescope is a core and critical component of the space gravitational wave detection system.Compared with ground-based telescopes, the on-orbit space environment is more complex and harsh, presenting higher technical challenges for the design of the optical system and structure - both optical design and structural design face considerable difficulties. To meet the requirements of space gravitational wave detection, this paper designs a laser emission telescope based on an off-axis four-mirror configuration, with a capture field of view of 300{\mu}rad, an optical transmission efficiency of 86.3%, and an optical path stability index of TTL

arXiv:2603.08673v1 Announce Type: new Abstract: Optical metasurfaces, comprised of subwavelength nanostructures, hold a great promise to high-power laser optics but also a limited pertinence due to their currently limited aperture size, throughput and durability. Here, an alternative approach is presented, reliant on laser-controlled self-organizing mask formation followed by ion etching which results in an all-fused-silica-glass metasurface. Two 1 mm diameter optical elements (an axicon lens and a shadower) are fabricated and their optical performance is validated at 532 nm wavelength with an extremely low broadband reflection (

arXiv:2603.08467v1 Announce Type: new Abstract: Soliton-similariton fiber lasers have demonstrated exceptional operational stability, maintaining continuous mode-locking for weeks despite large intracavity spectral and temporal breathing. We present the first stability study of this laser, rigorously establishing that the anomalous dispersion segment that supports the soliton is the cause of this robustness. Specifically, we perform linear stability analysis of the laser employing a Jacobian-based eigenvalue decomposition and show that the eigenvalues lie within the unit circle, leading to a positive stability margin, which is indicative of the robustness of the laser against small perturbations. Furthermore, the stability margin is observed to increase with the length of the anomalous fiber segment, clearly establishing its role in pulse stabilization. Critically, integrated pulse timing jitter and relative intensity noise as obtained from quantum noise-limited laser simulations are

arXiv:2603.08318v1 Announce Type: new Abstract: X-ray free-electron laser (XFEL) facilities require progressive compression of electron bunches as they are accelerated from an injector to the undulators. This is necessary to achieve the peak currents required for efficient lasing, without compromising transverse brightness. In the present generation of XFELs, high peak currents are achieved by means of a sequence of four-dipole bunch compression chicanes. It is well known that these systems are not ideal in that they allow projected emittance dilution at the percent level, and they exhibit amplification of microbunching, which typically must be controlled through the otherwise unwanted addition of slice energy spread by use of a laser heater. Both emittance dilution and microbunching are mediated through coherent synchrotron radiation that occurs within a bunch compression chicane. In this paper we introduce a new option for bunch compressors, that of full arc compression, and compare

arXiv:2603.06809v1 Announce Type: new Abstract: Relativistic lasers on solid targets generate hot electrons, and other secondary particles. These particles can be used for radiography, cancer therapy, or isochoric heating. A lower density or structured coating on high-Z targets can improve laser-target energy coupling and subsequently enhance overall particle emission. In this work performed at the Scarlet Facility, a $10^{21}$ W/cm$^2$ intense pulse was incident on front surface coatings on 1 mm thick Ta. These coatings include a 12 $\mu$m plastic coating, a 50 $\mu$m thick foam coating, and a Au nanowire (NW) coating. Post-damage craters are correlated with reflected light on a MACOR screen, illustrating that less absorption in a target is directly tied to smaller craters. Additionally, more absorption in a target also leads to more MeV electrons and X-rays. Bare targets performed the best for electron and MeV X-ray generation, with X-rays of 30 MeV detected, as coatings tested were

arXiv:2603.07525v1 Announce Type: new Abstract: Accurate and predictive scale-resolving simulations of laser-ignited rocket engines are highly time-consuming because the problem includes turbulent fuel-oxidizer mixing dynamics, laser-induced energy deposition, and high-speed flame growth. This is conflated with the large design space primarily corresponding to the laser operating conditions and target location. To enable rapid exploration and uncertainty quantification, we propose a data-driven surrogate modeling approach that combines convolutional autoencoders (cAEs) with neural ordinary differential equations (neural ODEs). The present target application of an ML-based surrogate model to leading-edge multi-physics turbulence simulation is part of a paradigm shift in the deployment of surrogate models towards increasing real-world complexity. Sequentially, the cAE spatially compresses high-dimensional flow fields into a low-dimensional latent space, wherein the system's temporal

Rosie Richardson wants to shift the onus to self protect away from women and on to the authorities.

arXiv:2603.06229v1 Announce Type: new Abstract: Photoexcitation is an inherent part of any photochemical or spectroscopic experiment, yet its impact on the excited-state dynamics is often overlooked. However, it is the excited molecular state, built upon photoexcitation and shaped by the characteristics of the light source, that determines the fate of the excited molecule and its subsequent photochemical reactions. In this work, we investigate how excited molecular states are built by different laser pulses, leveraging two representations of the molecular wave function: Born-Huang expansion and exact factorization. We explore the generation of two limiting cases: a stationary molecular state with a long laser pulse and an electronic wave packet by an ultrashort (attosecond) laser pulse. The standard concepts of population transfer between electronic states, resonance condition, or sudden vertical excitation, inherent to the Born-Huang representation and used by chemists to approximate

arXiv:2603.05282v1 Announce Type: new Abstract: Vacuum birefringence (VB), a fundamental prediction of nonlinear quantum electrodynamics (QED), has eluded direct laboratory detection due to its extreme weakness. We propose a compact, "self-probing" scheme where a GeV electron beam collides head-on with a petawatt laser pulse. Circularly polarized gamma-ray photons, generated via nonlinear Compton scattering in the same pulse, then probe the birefringent vacuum it induces. This integrated design bypasses the stringent synchronization and beam transport requirements of traditional pump-probe setups. Our nonperturbative strong-field QED simulations reveal a clear VB signature: conversion of circular to linear polarization, with the induced Stokes parameter $S_1$ reaching ~0.019 within the selected angular range. This corresponds to a refractive index difference $\Delta n = 1.829 \times 10^{-4}$ over micron-scale paths, directly measurable as a high-contrast "X-shape" asymmetry in

arXiv:2603.04853v1 Announce Type: new Abstract: Ultrafast laser writing of single lattice defects in wide-bandgap semiconductors is shown to present a new physical setting in which deeply subwavelength laser-writing positioning precision is attainable, but where the whole notion of positioning can only be understood in a statistical sense. We outline a framework for the analysis of this class of laser - matter interactions, grounding the concepts of optical super-resolution and subdiffraction positioning in statistical optics. Working along these lines, we derive closed-form solutions for physically meaningful quantifiers of laser-matter interactions on a subwavelength scale, suggesting a physically clear view of how deeply subdiffraction resolution can emerge from the interplay between determinism and stochasticity. We show that subdiffraction positioning precision in single-lattice-defect laser writing is achieved at the cost of a lower throughput, setting physical bounds on the

Most space missions rely on chemical rockets for propulsion. Rockets must carry fuel, which increases spacecraft mass and limits their speed and travel distance. For decades, researchers have explored light sails as an alternative. These devices use radiation pressure—the force exerted when light reflects from a surface—to generate thrust. When driven by a powerful laser, a light sail can accelerate continuously without onboard propellant, enabling faster travel across the solar system.

Astronomers using the MeerKAT radio telescope in South Africa have discovered the most distant hydroxyl megamaser ever detected. It is located in a violently merging galaxy more than 8 billion light-years away, opening a new radio astronomy frontier.

arXiv:2603.04213v1 Announce Type: new Abstract: We propose a monolithic, electrically driven source of photon pairs based on a non-linear AlGaAs Bragg reflection waveguide and a laser structure stacked on top. By introducing lateral tapers, the fundamental mode of the lasing waveguide is vertically coupled into a higher order mode of the Bragg reflection waveguide (Bragg mode) such that photon pairs can be generated through a type-II spontaneous parametric down conversion process. According to numerical simulations, a coupling efficiency of 28% is achieved between both modes. Phase matching the Bragg mode with two fundamental modes at 1550 nm results in a photon pair rate of 1.7*10^8 pairs/s for a 2 mm long device assuming 1 mW of power in the Bragg mode. Since the Bragg reflection waveguide does not require doping for this vertically coupled structure, free-carrier absorption losses and parasitic luminescence are avoided.

arXiv:2603.03990v1 Announce Type: new Abstract: Active topological photonic systems enable robust light control and new pathways for semiconductor lasing. However, their intrinsically non-Hermitian nature, combining gain, radiation leakage, and material loss, makes the underlying physics more complex, and prior studies have mostly focused on gain competition while the influence of loss channels is less examined. Here, we experimentally demonstrate radiative-channel-driven topological lasing in a valley photonic crystal consisting of isolated InP nanorods on an insulator, achieving room-temperature single-mode operation within an about 4 lambda scale cavity. Loss-included simulations show that material absorption and radiative leakage can be exploited to establish the lasing pathway. Local off-edge pumping provides spatial evidence of topological edge-guided lasing. Berry-curvature calculations, reflecting unit-cell symmetry breaking, verify the valley-Hall interface in a triangular

arXiv:2603.03840v1 Announce Type: new Abstract: Femtosecond pulsed laser systems constitute powerful tools for the high-precision structuring of materials at micro/nano-scale resolutions. A critical parameter influencing the efficacy of ultrafast laser-material interactions is the laser-induced damage threshold (LIDT), which is defined as the minimum laser fluence required to induce irreversible modification to the material surface. While extensive studies have addressed single-pulse damage mechanisms, the response of thin metallic films to double-pulse femtosecond irradiation, particularly when the film thickness is of the order of the optical penetration depth, remains, generally, unexplored. In this work, we present a rigorous theoretical investigation into the spatiotemporal evolution of energy deposition, thermalization processes and optical parameter changes under double-pulse excitation conditions. The analysis considers key parameters including the inter-pulse delay and the

Astronomers have discovered the brightest and most distant "megamaser" to date. The cosmic energy beam is shooting toward Earth from 8 billion light-years away and was spotted thanks to a weird space-time trick first predicted by Einstein.

arXiv:2603.02894v1 Announce Type: new Abstract: The dynamics of fast (e, 2e) collisions, induced by the impact of twisted electron beams, on atomic hydrogen, is analyzed in the presence of a laser field with circular and linear polarization. For the (e,2e) differential cross-section calculations we use Volkov and Coulomb-Volkov wave functions for scattered and ejected electrons, respectively, while the laser-atom interaction is treated in first-order perturbation theory. The formalism is developed for the asymmetric coplanar geometry in the first Born approximation. We investigate the influence of laser field polarization and provide a comparative analysis of Triple Differential Cross-Sections (TDCS) for circularly and linearly polarized laser fields as a function of ejected electron angle. The overall magnitude of the cross-section is larger for circular polarization as compared to linear polarization. Some notable changes in the angular distributions of TDCS were also observed for

When a bone break is too severe to heal on its own, surgeons often rely on grafts or rigid metal implants — but both come with serious drawbacks. Now, researchers at ETH Zurich have created a jelly-like hydrogel that mimics the body’s natural healing process, offering a potentially game-changing alternative. Made of 97% water, this soft material can be laser-printed into intricate bone-like structures at record-breaking speeds, down to details thinner than a human hair.

Researchers at the University of Basel and the ETH in Zurich have succeeded in changing the polarity of a special ferromagnet using a laser beam. In the future, this method could be used to create adaptable electronic circuits with light.

arXiv:2603.01262v1 Announce Type: new Abstract: Critical breakthroughs in the area of biomedicine and materials science increasingly depend on rapid, non-contact methods for viscoelastic characterization. Laser Speckle Rheology (LSR) is positioned to meet this demand, effectively circumventing the speed and invasiveness bottlenecks inherent to traditional mechanical rheometer. However, its application in turbid fluids is severely constrained by multiple scattering, where standard physical inversions rely heavily on precise, sample-specific optical transport parameters that are difficult to measure in situ. To overcome this barrier, we propose a physics-guided deep learning framework that infers a Maxwell relaxation spectrum from the intensity autocorrelation g2(t) and speckle-intensity histogram statistics. The resulting spectrum is then propagated through a Maxwell forward model to predict G'and G'' under physics-consistency constraints. Quantitatively, the framework achieves RMSElog

arXiv:2603.00548v1 Announce Type: new Abstract: Quantum-state preparation of molecular ions is a prerequisite for precision spectroscopy and controlled studies of cold ion-molecule dynamics. While such control has been extensively developed for diatomic ions and proposed for linear polyatomic ions, corresponding strategies for symmetric-top molecular ions remain largely unexplored. We present a theoretical investigation of blackbody-radiation (BBR)-assisted rovibrational dynamics and laser cooling in the symmetric-top ions NH3+ and ND3+, prepared in specific ro-vibrational states by resonance enhanced multiphoton ionization (REMPI) of the neutral precursor. State-resolved radiative lifetimes and equilibration times are computed, revealing that vibrationally excited states decay rapidly, while the ground-state redistribution is dominated by slow BBR-driven ro-vibrational transitions as pure rotational transitions are forbidden in the non-polar NH3+ and ND3+ ions. BBR-assisted laser

arXiv:2603.00294v1 Announce Type: new Abstract: High-brightness X-ray Free Electron Lasers (FELs) produce spatially and temporally coherent pulses on attosecond to femtosecond timescales, providing a transformative tool for discovery across biology, chemistry, physics, and materials science. However, most existing FELs are kilometer-scale facilities with billion-dollar construction costs and low repetition rates (about 100 Hz), which limits their accessibility and scientific throughput. This paper introduces a novel design for a compact, high-repetition-rate (MHz) EUV to 1 nm soft X-ray FEL with a footprint of less than 100 meters. This design is suitable for installation within university or research institution settings where space is limited. The facility leverages a multi-turn recirculating linear accelerator that integrates state-of-the-art superconducting accelerator technology with recent advances in diffraction-limited storage rings. We present the conceptual design and

arXiv:2603.00282v1 Announce Type: new Abstract: We report on magneto-optical trapping of the two fermionic isotopes of atomic titanium, $^{47}$Ti and $^{49}$Ti. Unlike the even mass-number isotopes, which were recently laser cooled, $^{47}$Ti and $^{49}$Ti have nonzero nuclear spins and, consequently, their atomic levels are split by hyperfine structure. Combining and comparing theoretical calculations and atomic beam-spectroscopy measurements, we determine the hyperfine structures and isotope shifts of the $\mathrm{3d^24s^2}$ $\mathrm{a^3F_4\rightarrow 3d^2(^3P)4s4p(^3P^o)}$ $\mathrm{y^5D_4^o}$ optical-pumping transition at optical wavelength 391nm and the $\mathrm{3d^3(^4F)4s}$ $\mathrm{a^5F_5\rightarrow 3d^3(^4F)4p}$ $\mathrm{y^5G_6^o}$ laser-cooling transition at wavelength 498nm. With this information, we produce magneto-optical traps of both $^{47}$Ti and $^{49}$Ti by applying two additional tones of light to repump atoms to the maximum-spin states on the laser-cooling

arXiv:2603.01425v1 Announce Type: new Abstract: LLMs have fundamentally transformed dense retrieval, upgrading backbones from discriminative encoders to generative architectures. However, a critical disconnect remains: while LLMs possess strong reasoning capabilities, current retrievers predominantly utilize them as static encoders, leaving their potential for complex reasoning unexplored. To address this, existing approaches typically adopt rewrite-then-retrieve pipelines to generate explicit CoT rationales before retrieval. However, this incurs prohibitive latency. In this paper, we propose LaSER, a novel self-distillation framework that internalizes explicit reasoning into the latent space of dense retrievers. Operating on a shared LLM backbone, LaSER introduces a dual-view training mechanism: an Explicit view that explicitly encodes ground-truth reasoning paths, and a Latent view that performs implicit latent thinking. To bridge the gap between these views, we design a

Lawrence Livermore National Laboratory's National Ignition Facility (NIF) is the hottest place on Earth for the briefest of moments during an experiment. Now, it can be one of the brightest places thanks to the Advanced Radiographic Capability (ARC), NIF's laser-within-a-laser. How this is possible and how it's measured is detailed in a paper in Physics of Plasmas titled "Development and scaling of MeV X-ray radiography at NIF-ARC."

Astronomers using the MeerKAT radio telescope in South Africa have discovered the most distant hydroxyl megamaser ever detected. It is located in a violently merging galaxy more than 8 billion light-years away, opening a new radio astronomy frontier.

A US military unit used a high-energy laser system to shoot down a Customs and Border Protection drone

arXiv:2602.24107v1 Announce Type: new Abstract: Plasma-based accelerators are compact and provide high gradients, yet their practical use has been limited by energy gain, stability, beam quality, and energy transfer efficiency. Here, we address several of these challenges simultaneously using a hybrid scheme in which an electron bunch from a laser wakefield accelerator (LWFA) drives a subsequent plasma wakefield accelerator (PWFA) stage with internal witness injection. Close to driver depletion in the PWFA stage, we obtain witness bunches with higher electron energy, reduced energy spread and divergence, and higher angular-spectral charge density compared to LWFA alone. We report energy transformer ratios approaching~2, and about 20\% of the initial energy in the drive beam was transferred to the witness bunch, thereby achieving a driver-to-witness energy transfer efficiency that largely surpasses that of all previous PWFA experiments.

arXiv:2602.23873v1 Announce Type: new Abstract: Stroboscopic nanoscale imaging with free electron laser light is revolutionizing our understanding of fast dynamics in heterogeneous systems. The short wavelength of X-ray and extreme ultraviolet radiation makes it possible to achieve nanoscale resolution, while resonance with atomic transitions gives access to electronic and magnetic degrees of freedom. Here, we report on our implementation of a recently developed imaging method, randomized probe imaging, at a free electron laser. The advantage of randomized probe imaging over existing methods is its compatibility both with extended and strongly scattering samples. Our implementation delivers robust single-shot reconstructions at up to a full-pitch resolution of 400 nm over a field of view with a 40 {\mu}m diameter. We also demonstrate single-shot imaging of magnetic domain structures using circular dichroism at resonance, paving the way to future time-resolved studies of magnetic

Simulated lunar dirt can be turned into extremely durable structures, potentially paving the way to more sustainable and cost-effective space missions, a new study suggests. Using a special laser 3D printing method, researchers melted fake lunar soil—a synthetic version of the fine dusty material on the moon surface, called regolith simulant—into layers and fused it with a base surface to manufacture small, heat-resistant objects.

Researchers demonstrate that femtosecond laser-induced transient Pauli blocking can achieve ultrafast, broadband optical switching from visible to near-infrared.

Plus, the company that just cut 4,000 jobs because of A.I.

arXiv:2602.22541v1 Announce Type: cross Abstract: Large, 3D trapped ion crystals offer improved sensitivity in quantum sensing protocols, and are expected to be implemented as platforms in near-future experiments. However, numerical techniques used to study the laser cooling of such crystals are inefficient as the number of ions, $N$, in the crystal increases. Here we develop a powerful numerical framework to simulate laser cooling of up to $10^5$ ions stored in a Penning trap. We apply this framework to characterize and optimize the cooling of ellipsoidal 3D crystals. We document new pathways to enhanced cooling based on the addition of an axial component to the potential energy-dominated $\boldsymbol{E}\times\boldsymbol{B}$ modes. Furthermore, we observe greatly enhanced cooling of the perpendicular kinetic energy to below 1 mK in prolate ion crystals, enabling a simplified cooling beam setup for such crystals. We propose specific values of trap and laser beam parameters which lead

arXiv:2602.22460v1 Announce Type: cross Abstract: Ultrafast lasers create extreme, non-equilibrium thermodynamic conditions that can transiently reach pressures and temperatures comparable to interior core of the earth. Here we show that femtosecond excitation of amorphous silica-hafnia multilayer dielectrics drives the formation of high-pressure crystalline phases of silica including stishovite, seifertite, and the pyrite-type high density structure, within confined subsurface regions.Using TEM, SAED, and 4D-STEM, we directly map nanoscale phase evolution and identify crystalline motifs embedded inside laser generated blisters.Complementary molecular dynamics simualtions reveal the thermodynamic pathway underlying these transformations, where rapid electronic pressure initiates densification and octahedral coordination, followed by temperature driven crystallization and displacive transitions during ultrafast quenching. The resulting polymorphs reflects a dual-stage pathway

arXiv:2602.22841v1 Announce Type: new Abstract: Self-guided femtosecond laser pulses propagating in low-pressure gas can generate plasma filaments, establishing a new framework for plasma wakefield acceleration. Unlike conventional schemes relying on mechanically confined or preformed plasma channels, this method exploits the intrinsic non-linear light-matter interaction, greatly reducing the energy required to generate plasma. This, in turn, allows to realise tunable stages, potentially operating above kHz repetition rate and with meter-scale interaction lengths and transverse sizes down to a few tens of micrometres. Moreover, the laser-plasma filament reproducibility is intrinsically higher than state-of-the-art discharge-plasmas, where the breakdown process is initiated in a stochastic and uncontrolled manner. As a result, laser-based plasma formation offers improved reliability and control over plasma parameters. Here we report a proof-of-principle experimental demonstration of

After the downing of a Customs and Border Protection drone, the F.A.A. closed the airspace above Fort Hancock, Texas.

Messenger RNA (mRNA) technology is transforming medicine by providing our cells with genetic instructions to produce proteins that help the immune system prevent or fight a wide range of diseases, including cancer and other rare disorders.

Messenger RNA (mRNA) technology is transforming medicine by providing our cells with genetic instructions to produce proteins that help the immune system prevent or fight a wide range of diseases, including cancer and other rare disorders. Before the molecule can help fight disease, mRNA is packaged into lipid nanoparticles to protect it from rapid degradation. These fatty, protective bubbles act as a delivery vehicle, ensuring the mRNA properly enters the cell to deliver instructions for protein production.

Lasers cut precisely and without contact – ideal for surgery. The problem is that, in hard tissues such as bone, they are too slow and do not cut deep enough.

High-grade astrocytoma, which includes glioblastoma, is a fast-growing, aggressive brain cancer that often returns after the tumor is removed, making it difficult to treat. Patients

arXiv:2602.22172v1 Announce Type: new Abstract: Laser wakefield acceleration (LWFA) can produce relativistic electron beams and various secondary particles in centimeter-long plasmas, making it a valuable particle source with important applications in many disciplines. In this work, we examine the effects of non-ideal transverse intensity and phase distribution of laser pulses on LWFA through both experimental measurements and particle-in-cell simulations. The complex transverse profile of the 75 TW laser pulses reduces the self-focused intensity in plasma compared with a transversely Gaussian laser. Furthermore, the sheath structure of the nonlinear plasma wake excited by realistic laser pulses is wider and more complicated than that of a Gaussian laser. These hinder the injection of the plasma electrons. As the laser pulse propagates through the plasma, its intensity profile gradually becomes elliptical and drives a plasma wake with a sharp sheath near the azimuths of the major

arXiv:2602.21732v1 Announce Type: new Abstract: In this study, we developed a UV-tape-assisted laser patterning (UT-Laser) technique that enables the simple transfer-based formation of wiring with line widths below 200 $\mu$m onto textile substrates. With the rapid advancement of wearable devices capable of acquiring various types of physiological and environmental information, research on electronic textiles (e-textiles)-in which electronic components are integrated into fabrics and clothing-has progressed considerably. However, integrating high-performance, rigid electronic components onto textiles remains challenging: the diameter of textile fibers limits the formation of fine wiring, making reliable mounting of such components difficult. To address these challenges, we devised the UT-Laser technique, in which thin foil or film materials are laser vector-cut on UV tape, and the adhesive strength is controlled through UV exposure. The unnecessary portions are selectively and

arXiv:2602.21709v1 Announce Type: new Abstract: Accurate forest stand delineation is essential for forest inventory and management but remains a largely manual and subjective process. A recent study has shown that deep learning can produce stand delineations comparable to expert interpreters when combining aerial imagery and airborne laser scanning (ALS) data. However, temporal misalignment between data sources limits operational scalability. Canopy height models (CHMs) derived from digital photogrammetry (DAP) offer better temporal alignment but may smoothen canopy surface and canopy gaps, raising the question of whether they can reliably replace ALS-derived CHMs. Similarly, the inclusion of a digital terrain model (DTM) has been suggested to improve delineation performance, but has remained untested in published literature. Using expert-delineated forest stands as reference data, we assessed a U-Net-based semantic segmentation framework with municipality-level cross-validation

arXiv:2602.20538v1 Announce Type: new Abstract: Emulating long-distance light propagation on a laboratory scale is essential for the ground-based testing of intersatellite optical systems. To address this challenge, we propose and analyze a novel optical system called the Range Emulator (RE) to reproduce the spatial propagation effects of a long-distance beam within a compact apparatus. Our analysis identifies that three lenses are required as the minimum number of lenses to implement the RE. Through a numerical exploration, we quantify the fundamental trade-off between system compactness and manufacturing precision. This work provides a practical framework for designing compact optical testbeds for future multi-satellite laser link technologies.

arXiv:2602.20460v1 Announce Type: new Abstract: The differential sparing of normal tissues relative to tumor control observed at ultra-high dose rates, referred to as the FLASH effect, has recently gained considerable attention. The therapeutic advantages of FLASH radiotherapy are expected to be further amplified through the use of protons and ions, which enable precise dose deposition at tumor depth while minimizing irradiation of healthy tissues proximal and distal to the target. Nevertheless, the mechanism underlying this sparing effect remains poorly understood. Laser-driven proton accelerators are capable of delivering uniquely high instantaneous dose rates in ultrashort bunches. Here, we report the first in vivo investigation of normal tissue response to laser-driven proton irradiation. Our findings reveal a reduction in tissue swelling following laser-driven proton treatment compared with X-ray irradiations at conventional dose rates. RNA sequencing identified differential gene

arXiv:2602.18619v1 Announce Type: new Abstract: Laser-target interactions generate intense electromagnetic pulses (EMP) that can interfere with measurements and damage equipment. In this paper we show that applying a magnetic field to nanosecond pulse laser-target interactions decreases the magnitude of EMP. We demonstrate this effect in two experiments with different geometries (spherical vs. planar), laser intensities (${\sim}10^{13}$ vs. ${\sim} 10^{15}$~W/cm$^2$) and applied field strength (12~T vs. 0.1~T) that both observed suppression of EMP in the ${\sim} 1$~GHz band (by factors of $0.65\times$ and $0.32\times$ respectively). We then observe the opposite effect at high intensities with a picosecond pulse: for planar experiments with laser intensities ${\sim}10^{19}$~W/cm$^2$ and magnetic fields of 6--10~T, the magnitude of EMP is increased by a factor of $1.75\times$. These results provide a benchmark for models of EMP generation, but suggest that magnetic fields are not a

arXiv:2602.18544v1 Announce Type: new Abstract: Chorus waves are electromagnetic waves named for their resemblance to birds chirping at dawn when their radio frequencies are played as audio. The amplification of chorus in Earth's magnetosphere has been the subject of intense scientific inquiry since the discovery of the Van Allen radiation belts in 1958. Resonant interactions between chorus and radiation belt electrons can lead to the exponential growth of small seed waves by a factor of fifty within milliseconds. These powerful modes can cause rapid acceleration of electrons and endanger space-based technologies. Recent efforts to understand chorus amplification have drawn upon parallels to free-electron lasers, laboratory devices that generate intense coherent light with tunable frequencies. This approach, known as the free-electron laser model of magnetospheric chorus, is the subject of this dissertation. In this work, we build on previous research on the free-electron laser model,

arXiv:2602.19238v1 Announce Type: new Abstract: Spatially distributed cavity (SDC) lasers are a promising technology for simultaneous light information and power transfer (SLIPT), offering benefits such as increased mobility and intrinsic safety, which are advantageous for various Internet of Things (IoT) devices. \mll However, achieving beam transmission over meter-level long working distances presents significant challenges from cavity stability constraints, manufacturing/assembly tolerances, and diffraction losses\mrr. This paper conducts a theoretical investigation of the fundamental restrictions limiting long-range resonant beam generation. We investigate cavity stability and beam characteristics, and propose a binary-search-based Monte Carlo simulation algorithm as well as a linear approximation algorithm to quantify the maximum acceptable tolerances for stable operation. \mll Numerical results indicate that the stable region contracts sharply as distance increases. For

Laser shockwaves convert carbon nanotube films into multilayer graphene without external heating, boosting thermal conductivity sevenfold in a single chemical-free step.

arXiv:2602.18368v1 Announce Type: new Abstract: Optimisation problems, which appear in numerous fields of science and industry, are challenging to solve even with modern supercomputers. Many such problems can be mapped onto ground-state searches of spin Hamiltonians, implemented on various physical platforms whose intrinsic dynamics are analogous to spin systems. However, the complex energy landscape of spin Hamiltonians often traps the system in local minima, preventing the system from reaching the ground-state (global minimum). We demonstrate an intrinsic feedback-driven annealing mechanism in class-B semiconductor laser arrays arising from the interplay of internal ($\alpha$) and external ($\eta$) coupling. The instantaneous phase configuration self-modulates amplitude fluctuations, which act as an effective temperature, dynamically reshaping the potential and enabling the system to escape from local minima. Using a one-dimensional ring laser array, we analyze defect formation in

Colliding galaxies can create a beam of focused microwave radiation known as a maser, and astronomers have discovered the brightest one ever seen

arXiv:2602.17368v1 Announce Type: new Abstract: Singular optics has emerged as an important research area with diverse applications, yet controlling optical singularities in nanophotonic emitters is typically limited by fixed subwavelength geometries and diffraction-limited control. Here, we circumvent this limitation and demonstrate an all-optical mechanism for reconfiguring far-field singularities in a photonic crystal laser. The underlying principle involves optical pumping, which creates a mesoscopic potential landscape whose spatial variations are slow compared to the lattice period. Such a potential localizes a Bloch band into trapped states whose envelope functions, and thus far-field singularity textures, are defined by the pump geometry. Using a honeycomb photonic crystal that supports a symmetry-protected bound state in the continuum, we achieve room-temperature telecom-band lasing with real-space polarisation singularities that are reconfigurable in both number and

arXiv:2602.17042v1 Announce Type: new Abstract: Quantum cascade lasers (QCLs) are unipolar semiconductor lasers first demonstrated in 1994. Since then, they have played a central role in advancing mid-infrared and terahertz photonics, becoming among the most reliable light sources in these regions of the electromagnetic spectrum. Their importance is further reinforced by their ability to generate self-starting optical frequency combs, whose investigation is motivated both by fundamental physics and by a wide range of applications, including molecular spectroscopy and free-space optical communications. This Roadmap provides a unified overview of current advances and emerging directions in QCL research. The chapters are organized into three main sections: device design and technology; frequency combs and pulse formation; and applications of QCLs. Each chapter reviews the relevant background, summarizes the current state of the art, and identifies key challenges and future directions

arXiv:2602.16884v1 Announce Type: new Abstract: Hard x-ray emission, associated with hot electron preheat, in direct-drive implosions was observed to be enhanced by a factor of $1.5\pm0.1$ by application of a $10$ T magnetic field. The applied magnetic field reaches a quasi steady-state aligned with the ablation flow prior to the onset of laser-plasma instabilities in the corona. Hot electrons that would otherwise escape the corona and lead to capsule charging in unmagnetized implosions are confined in a mirror-mode of the magnetic field in magnetized implosions. These hot electrons are shown to subsequently pitch-angle scatter from the mirror onto the capsule, thereby leading to the observed hard x-ray generation in magnetized implosions. Consequently, the energy of charged-fusion products, associated with the capsule charging, are observed to decrease when the implosion is magnetized. These results intensify the need to mitigate laser-plasma instabilities -- particularly for

arXiv:2602.17263v1 Announce Type: new Abstract: Controlling the longitudinal laser pulse shape in photoinjectors of Free-Electron Lasers is a powerful lever for optimizing electron beam quality, but systematic exploration of the vast design space is limited by the cost of brute-force pulse propagation simulations. We present a generative modeling framework based on Wasserstein Autoencoders to learn a differentiable latent interface between pulse shaping and downstream beam dynamics. Our empirical findings show that the learned latent space is continuous and interpretable while maintaining high-fidelity reconstructions. Pulse families such as higher-order Gaussians trace coherent trajectories, while standardizing the temporal pulse lengths shows a latent organization correlated with pulse energy. Analysis via principal components and Gaussian Mixture Models reveals a well behaved latent geometry, enabling smooth transitions between distinct pulse types via linear interpolation. The

arXiv:2602.16461v1 Announce Type: new Abstract: Photonic integration offers the potential to bring complex high-performance optical systems to the form factor of a compact semiconductor chip. However, the range of system functions accessible critically depends on the extent to which free-space and fiber components can be made integrable. The ultralow-expansion cavity-stabilized laser$-$often used in precision metrology, high-resolution sensors, and advanced systems in atomic physics$-$is one component that currently has no direct parallel on chip. Lasers stabilized to photonically-integrated resonators exist, but exhibit considerably higher frequency noise and are accompanied by large levels of frequency drift. We demonstrate here a new architecture for an ultranarrow linewidth integrated laser based on stabilization to a sinusoidal fringe of an interferometer having a long 25-m unbalanced delay line. Our interferometric laser not only advances the state-of-the-art for on-chip lasers,