Laser

Cislunar space is already getting crowded. And with that crowding comes infrastructure complications. One is navigation - there is no Global Positioning System available when you're not on the globe. Finding a spacecraft’s exact orbital path relies on networking with the Deep Space Network (DSN), a set of telescopes originally developed in the 1950s to communicate with spacecraft far afield. DSN itself is already getting overwhelmed with managing all of the missions requesting its time, so getting a precise orbital location currently can take hours. But researchers at MIT’s Lincoln Laboratory think they might have a solution for this - launching a fleet of three satellites to collectively create a deep-space navigational system known as the LIght High-Orbit Utility Signal Emitter - LightHOUSE.

arXiv:2608.28506v1 Announce Type: cross Abstract: Phase-space methods are powerful tools for the treatment of Markovian open quantum systems: they map the reduced dynamics of a system S, in interaction with an environment E, exactly onto Langevin equations for c-number stochastic variables, as opposed to Heisenberg-Langevin equations for operators. Langevin equations provide analytical insight in key regimes and excel at handling strong nonlinearities and couplings, where other methods often falter. Extending phase-space methods to non-Markovian dynamics, however, has remained a long-standing challenge. Here we address this gap by applying phase-space representations to the full S+E system; integrating out the environmental degrees of freedom then yields a general Langevin framework for S that incorporates both deterministic and stochastic contributions from E. Normally ordered representations, such as the Glauber-Sudarshan P representation and its positive variant due to Drummond and

arXiv:2608.28098v1 Announce Type: cross Abstract: Infrared heterodyne interferometry offers a scalable alternative to direct interferometry for long-baseline telescope arrays. However, at near-infrared wavelengths, its sensitivity is limited by the electronic detection bandwidth and shot noise from the optical reference. Parallel detection via spectral multiplexing has long been identified as a potential means to increase the signal-to-noise ratio of heterodyne interferometers. We propose a new heterodyne detection architecture based on highly dispersed broadband pulses from a mode-locked laser, fast photoreceivers, and numerical correlation. This enables straightforward spectral multiplexing with commercial components to increase the SNR, while extending instantaneous wavelength coverage to simultaneous J- and H-band operation. The scheme also supports high-resolution spectroscopic imaging ($R \simeq 10^{3}-10^{4}$). We derive the SNR of a two-arm heterodyne interferometer based on

arXiv:2608.28466v1 Announce Type: new Abstract: Mesospheric sodium magnetometry with a laser guide star measures the geomagnetic field near 90~km. Its sensitivity hinges on laser linewidth and chirp, yet prior work optimized these two parameters only separately. We use velocity-resolved density-matrix simulations of Larmor-synchronous pulsed Na D$_2$ pumping to scan both parameters jointly. Linewidth and chirp exhibit a synergy: when chirping carries the recoil-mitigation role, the return flux stays within 1\% of its peak across linewidths of 2--10~MHz. The flux-optimal chirp is $0.19~\mathrm{MHz/\upmu s}$, one fifth of the continuous-wave rate; this synergy guides high-sensitivity mesospheric magnetometer design.

arXiv:2608.28423v1 Announce Type: new Abstract: Reliable material joining is essential for countless industrial applications. While femtosecond laser welding provides a route beyond conventional bonding methods, demonstrations of silicon-metal joints are rare due to nonlinear propagation effects and have so far been limited to shear joining strengths of a few MPa. Here, we demonstrate high-strength silicon-Kovar laser welding using sub-nanosecond pulses. By optimizing the focal position, the welding pattern, the laser polarization, and the metal roughness, remarkable shear joining strengths up to 15.8 MPa are achieved. The silicon-metal joints withstand temperatures of up to 500 {\deg}C and are hermetically sealed. Together with the remarkable strength values, the resistance to harsh environments underpins the applicability of silicon-metal welding in various fields including aerospace, nuclear science, and metallurgy.

arXiv:2608.27700v1 Announce Type: new Abstract: We present a quantitative study of laser absorption on the $5{^{2}}\mathrm{S}_{1/2} \rightarrow 5{^{2}}\mathrm{P}_{3/2}$ transition of silver in a hollow-cathode lamp. Spectra obtained using a weak probe are measured and compared to a simple theoretical model. We fit our results to extract an effective temperature and number density associated with the silver in the lamp and confirm that the spectra are dominated by Doppler broadening. We consider the broadening effect of collisions between silver and the neon buffer gas in the lamp, and establish that these effects are small but modify the optimum effective parameters for the model. Our work results in a simple, quantitative, and predictive model for laser absorption in the lamp.

Researchers followed 787 patients with brain tumors treated with laser therapy for up to 5 years.

arXiv:2608.25137v1 Announce Type: new Abstract: A $\gamma\gamma$-collider capable of reaching the 10 TeV parton-center-of-momentum (pCM) frontier of particle physics may enable the study of phenomena beyond the Standard Model. Based on compact linear wakefield accelerator technology, such a collider could be realized by Compton scattering multi-TeV lepton beams off moderate-intensity laser pulses close to the collider interaction point, producing the required $\gamma$-photons. It is shown that, for a wide range of scattering-laser wavelengths, $\gamma\gamma$-collisions at the interaction point can meet the luminosity requirements for novel particle physics studies, even in the presence of the prolific electron-positron pair production that accompanies the interaction of the scattering laser with the multi-TeV lepton beam. Notably, this pair production imposes a natural limit on the maximum achievable photon luminosity. Accounting for this limit and for the angular divergence of the

arXiv:2608.25020v1 Announce Type: new Abstract: We have developed a compact passive energy-selector for MeV-range electrons produced by irradiating solid targets by ultra-intense short-pulse lasers. The device allows for generating electron beams with a variable energy spread over a broad range of energies, from tens of keV to tens of MeV. Here we have demonstrated its use by producing electrons from solid targets in the MeV range and with a ~10% bandwidth, thereby compensating the intrinsic broadband nature of the electrons produced from such source. Coupled with a pulsed magnetic field to further compensate the intrinsic large divergence of this source, it allows to produce a highly-collimated beam of narrow-band and ultra-fast electrons, suitable for a wide range of applications, e.g. radiation therapy or time-resolved electron probing.

arXiv:2608.25928v1 Announce Type: new Abstract: Agentic systems enable the intelligent automation of complex workflows, specific to additive manufacturing this is applicable for complex tasks such as process parameter optimization for mechanical properties. This work investigates the AI enabled agentic process optimization within Selective Laser Sintering (SLS) to iteratively improve the tensile and flexural properties of 3 different materials on the Inova Mk1. These materials include PA12 GF, PA11 Onyx, and PA12 Blend (volume mixture of 25% PA12 GF and 75% PA12 White) and with using knowledge from previous builds and minimal guidance from the user, the agentic system was able to optimize process parameters over a small number of iterations to achieve comparable TDS specified mechanical properties. This work showcases the ability for an agentic system to continually learn from updated data, enabling the intelligent automation of complex tasks such as process parameter optimization for

arXiv:2608.23768v1 Announce Type: new Abstract: We report multi-hour stable trapping and steady state of non-laser-coolable Cs$^{+}$ ions in a linear Paul trap, achieved via resonant charge-exchange (RCE) cooling with a precisely centered ultracold Cs cloud. Without cold atoms, all ions are lost within 3 minutes. With centered cold atoms, RCE cooling establishes a stable population of ions for 6 hours with no measurable decay -- more than two orders of magnitude longer hold times compared to prior hybrid atom-ion systems. We observe a threshold behavior in the steady-state number of ions ($N_{s}$): initial ion loadings above $N_{s}$ ions converge downward to $N_{s}$ ions and remain constant thereafter; initial loadings below $N_{s}$ ions show no measurable decay. The dynamics is governed by a competition between ion-ion rf heating and ion-atom collisional cooling. The prolonged, simultaneous ion-atom trapping suggests an upper bound on the three-body recombination-induced Cs$_{2}^{+}$

arXiv:2608.23604v1 Announce Type: new Abstract: Laser-induced-desorption quadrupole-mass-spectrometry (LID-QMS) diagnostics is considered as one of the candidate methods for the remote control of tritium inventory in the ITER first wall. Studies involving LID-QMS generally assume the circular shape of the laser spot on the analyzed surface. At the same time, the diagnostics laser source cannot be always positioned so as to irradiate tokamak tiles under normal angles, which results in the laser spot shape differing from the circular one. In this contribution, we analyze the tritium removal process under sample irradiation by an elliptic Gaussian laser beam, extending the results of our previous analysis [Stepanenko, Gasparyan, Physica Scripta 99 (8), 085604 (2025)]. The thermal desorption model governing the heat transport and tritium removal from the solid is formulated. The new analytical expression describing the sample temperature dynamics is derived. The developed model is used to

arXiv:2608.23466v1 Announce Type: new Abstract: Plasma jets are formed in various astrophysical systems as plasma is rapidly ejected from a source, with a subset of these jets being magnetized and having a helical structure. Here, we demonstrate that helical jets may be formed using a ring of laser pulses that arrive on planar foils sequentially with increasing energy. The formation of the jets and their properties, including kinetic helicity, are studied through a set of three-dimensional magneto-hydrodynamics simulations with conditions informed by the parameters of the OMEGA laser facility. We find that jets with a higher degree of helicity may be generated under realistic experimental conditions when compared to a uniform jet. Synthetic x-ray and Thomson scattering diagnostics computed from simulated data demonstrate that the helical jet provides a unique fingerprint in both its morphology and plasma parameters. This laboratory helical jet platform may allow for controlled

arXiv:2608.22825v1 Announce Type: new Abstract: We propose a novel, highly efficient method for isolating the isomeric state $^{26\text{m}}\text{Al}$ from an overwhelming ground-state $^{26\text{g}}\text{Al}$ background (isomeric ratio $\sim 20:1$) using optical pumping through a 2.0 m flight zone in collinear laser spectroscopy (CLS). To investigate the underlying optical pumping (OP) dynamics, we developed a comprehensive rate equation framework. While the transition pathways can be intuitively conceptualized via a primary 7-manifold scheme, our numerical simulation solves the full 47-level rate equations by explicitly accounting for all degenerate Zeeman sublevels ($m_F$) to rigorously incorporate polarization selection rules and Clebsch-Gordan coefficients. When the continuous acceleration voltage matches the resonance conditions of the $^{26\text{g}}\text{Al}$ hyperfine transitions, the ground-state atoms undergo a 100% efficient transition into uncoupled dark states within the

arXiv:2608.22545v1 Announce Type: new Abstract: Laser-induced plasmas are primarily characterized by their temporal density decay. Using time-resolved transverse optical diffractometry, we reveal their concurrent spatial evolution, demonstrating pronounced broadening and flattening during the first 200 ps following ionization. This non-self-similar evolution arises from the local density dependence of electron-ion recombination, without particle transport. Exploiting the continuum of initial densities within a single plasma disc, we experimentally reconstruct an effective, time-dependent local recombination law over a broad density range. Applied locally to independently measured initial plasma profiles, this kinetic map quantitatively predicts their subsequent evolution. These results are relevant to transient diffractive optics, plasma-based optical elements and waveguides, and the development of laser-induced plasmas as platforms for gas-phase THz plasmonics.

arXiv:2608.22211v1 Announce Type: new Abstract: We investigate electron injection into direct laser acceleration (DLA) in relativistic laser-driven plasma channels using particle-in-cell simulations. We identify and characterize a wavefront-guided injection mechanism, in which electrons are continuously fed into the plasma channel through the density pile-up layer at the laser-pulse front. Phase-space analysis reveals a localized injectable region within the pile-up layer, indicating that only a selected subset of electrons satisfies the conditions required for the subsequent direct laser acceleration. This mechanism provides a physical interpretation for the high-charge capability of DLA by explaining how electrons are continuously supplied to the accelerating channel. Beyond this continuous supply process, the injection dynamics are further modulated by the periodic variation of the carrier phase at the laser-pulse front. The spatial locations of injected electrons are found to be

arXiv:2608.21527v1 Announce Type: new Abstract: Silicon-based technology has been at the forefront of electronic and photonic research since the dawn of the electronic revolution. However, silicon is fundamentally an indirect-bandgap semiconductor: the conduction band minimum and valence band maximum occur at different points in momentum space, so optical transitions require phonon assistance to conserve crystal momentum. This three-body electron-photon-phonon interaction renders silicon an inefficient material for light-absorbing applications such as solar cells and optoelectronic devices. In this work, we build on an established nanoscale photon-momentum confinement mechanism, which broadens the photon momentum distribution and enables phonon-free absorption in silicon, by subsequently applying a high-intensity femtosecond pulsed excitation that injects hot carriers beyond the Mott density, collapsing the bandgap and inducing a reversible semiconductor-to-metal transition. While

Russian military outlet Zvezda TV has unveiled a man-portable laser system designed to disable mines Read Full Article at RT.com

Researchers have helped unravel the mystery of why certain pairs of stars pulse with regular, long-period bursts of radio waves. The particular class of objects they observed come in pairs that always include a compact dead star, called a white dwarf, locked in orbit with an M dwarf, a red star smaller than our Sun.

When physicists at the ARC Centre for Transformative Meta-Optical Systems (TMOS) needed a key component for their terahertz experiments, they ran into a frustrating problem—they needed tiny optical devices, known as wire-grid polarizers, but these cost thousands of dollars each.

arXiv:2608.20124v1 Announce Type: new Abstract: Few-mode photonic circuits can increase functionality without multiplying waveguide paths, but bends and fabrication errors can mix their transverse modes. We investigate a strategy in which waveguide confinement and perturbation parity are engineered together in vertically elliptical, femtosecond-laser-written glass waveguides. The intended modal basis comprises the even $1S$ mode and the vertically odd $2P_y$ mode. No window-converged $2P_x$ state is resolved for a lower-confinement (LC) design, whereas a higher-confinement (HC) design guides $2P_x$, which must therefore be isolated by symmetry. In scalar beam-propagation calculations, the $1S$-$2P_y$ propagation-constant splitting predicts the optimized periods of a vertically modulated coherent modal splitter to within $1.0\%$. Horizontal S-bends remain parity-mismatched for $1S \leftrightarrow 2P_y$ coupling, while the symmetry-allowed HC $1S \rightarrow 2P_x$ transfer reaches only

arXiv:2608.20027v1 Announce Type: new Abstract: Dielectric laser accelerators (DLAs) represent a compact and cost-effective alternative to conventional RF accelerators. Despite the various grating geometries already studied, a comprehensive investigation of triangular profiles, particularly the effect of the base angle of the saw-tooth grating profile, remains insufficient. This paper presents the results of numerical particle-in-cell (PIC) simulations of electron acceleration in DLAs based on double gratings with a triangular profile. One of the gratings, onto which the laser beam is incident, is transparent, while the second grating was either transparent or reflective for the laser pulse. The geometry of the first grating was fixed. A systematic study was conducted on the influence of the base angle of the second grating ($\alpha = 5^\circ - 44^\circ$), its spatial orientation, the presence of a reflective gold coating, and the shape of the incident laser pulse (plane wave versus

arXiv:2608.20022v1 Announce Type: new Abstract: We demonstrate the production of mutually phase-stable attosecond X-ray pulse pairs with tunable relative time delays and phases in a cascaded X-ray free-electron laser. We showcase the method in an experiment at the LCLS-II, in which a shaped electron beam is used in a split undulator configuration to generate the two attosecond pulses. We achieve mutual phase stability by reusing microbunching generated in the first undulator in order to seed the FEL process in the second at a detuned frequency. We measure controllable temporal delays between the two pulses directly in the time domain using angular streaking of photoelectrons, with a step size of 250 attoseconds. We then show that the behavior of the X-ray spectrum is consistent with phase stability between the two pulses, with a relative phase that can be easily tuned using inter-undulator phase shifters. This method is particularly well-suited to few to ten eV energy separations and

arXiv:2608.19591v1 Announce Type: new Abstract: This paper presents an experimental investigation of magnetic reconnection between two laser-produced expanding plasmas, focusing on the quantitative evaluation of the reconnection rate and energy conversion under varying initial conditions. By changing the separation distance between the drive laser focal spots (1 mm and 2 mm), we systematically controlled the inflow parameters. The reconnection region was probed using a two-directional laser Thomson scattering (LTS) system, which simultaneously measured the local plasma parameters parallel to the outflows and along the current sheet. Based on our established method incorporating macroscopic energy and mass conservation laws to derive the upstream magnetic field directly from LTS spectra, we characterized the temporal evolution of the current sheet and the reconnection rate. The larger spot separation allows the plasma bubbles to expand for a substantially longer time before the

arXiv:2608.18718v1 Announce Type: new Abstract: It is well known that electron-positron pairs can be created in the strong-field environments formed by (i) a high-intensity laser field and a high-energy $\gamma$-photon (nonlinear Breit-Wheeler process) or (ii) a high-intensity laser field and a nuclear Coulomb field (nonlinear Bethe-Heitler process). Both of these processes are particularly interesting in the interaction regime where the laser field enters nonperturbatively. Various experimental collaborations are currently aiming at detecting for the first time the nonperturbative Breit-Wheeler process, by exploiting high-intensity laser pulses and $\gamma$-ray sources based on bremsstrahlung. In contrast, an experimental observation of the nonlinear, nonperturbative Bethe-Heitler process still lies further ahead in the future because its technical realization appears at present more challenging. Our comparative study shows, however, that the physical properties of the total rates

arXiv:2608.18393v1 Announce Type: new Abstract: We investigate intramolecular hydrogen migration in acetonitrile dication in phase-controlled $\omega$-$2\omega$ intense laser fields (800 and 400 nm, 3.3$\times$10$^{14}$ W/cm$^2$) using three-dimensional coincidence ion momentum imaging. The two-body Coulomb explosion pathway, CH$_3$CN$^{2+}$ $\rightarrow$ CH$_3^+$ + CN$^+$, exhibits a clear phase-dependent fragment asymmetry along the laser polarization direction, showing that the tunnel ionization preferentially prepares the acetonitrile dication with the methyl group pointing toward the smaller amplitude side of the laser electric fields. The Coulomb explosion pathway occurring after the migration of a single hydrogen atom, CH$_3$CN$^{2+}$ $\rightarrow$ CH$_2^+$ + HCN$^+$, shows a pronounced reduction in the fragment asymmetry. A clear deuteration effect observed for the asymmetry of the hydrogen-migration pathway suggests that the two-color asymmetric laser field has a significant

arXiv:2608.17772v1 Announce Type: new Abstract: Direct laser acceleration (DLA) in near-critical-density (NCD) plasmas can efficiently generate high-charge relativistic electron beams, yet beam parameters depend critically on precise plasma state manipulation. Solid-ablation NCD plasmas evolve rapidly, posing severe controllability challenges. We produce NCD plasma via indirectly heating foam targets with ns laser driven hohlraum soft X-ray. Electrons are generated through irradiating the plasma with another picosecond laser. Tuning the laser pulse delay $\tau$ enables control of plasma profiles and beam parameters. Experiments show that when the foam is heated ($\tau$ = 6 ns, 9 ns), the beam exhibits $T \sim 13$ MeV effective temperature, $E_k \sim 80$ MeV cutoff energy, and hundreds of nC/sr charge for $E_k > 7.5$ MeV. These values are significantly higher than those from solid-foil ($T$ $\sim$ 2.7 MeV, $E_k$ $\sim$ 20 MeV, $Q$ $\sim$ 9 nC/sr) and cold-foam ($T$ $\sim$ 12 MeV, $E_k$

arXiv:2608.17555v1 Announce Type: new Abstract: Pump-probe experiments using dual ultrashort X-ray pulses provide unique opportunities for resolving non-equilibrium dynamics initiated by intense X-ray excitation. Betatron radiation from laser wakefield accelerators offers femtosecond duration, micrometer-scale source size, and intrinsic synchronization with the driving laser, making it a promising candidate for compact ultrafast X-ray sources. Here, we experimentally demonstrate a high-flux, dual-pulse betatron X-ray source based on a density-tailored gas-mixture target. Two electron bunches are generated within a single plasma wakefield through ionization-induced and shock-front-triggered injection, subsequently producing twin X-ray pulses. The measured electron spectra and dual-component X-ray angular profiles, together with particle-in-cell simulations, identify the contributions of the two electron populations to the radiation. The total X-ray photon yield reaches the level of

arXiv:2608.17554v1 Announce Type: new Abstract: Successive innovations in particle accelerators have continually expanded the frontiers of scientific discovery. Laser wakefield accelerators promise to transform science, medicine, and industry, yet moving them from laboratory demonstrations to reliable real-world operation has remained a central, long-standing challenge. Here we report a field-deployable system that produced 100-MeV-class electron beams with 1%-level energy stability during 72 hours of continuous operation and supported routine full-power use throughout a seven-month field trial in an industrial setting. Applied to in situ micro-nondestructive testing, the system generated tens-of-MeV bremsstrahlung X-rays that enabled three-dimensional microtomography of dense materials at sub-50-{\mu}m spatial resolution and revealed 100-{\mu}m-scale internal defects in large composite structures, extending the capabilities beyond those of existing high-energy X-ray sources. These

arXiv:2608.17460v1 Announce Type: new Abstract: Single Particle Imaging with intense X-ray free-electron laser pulses requires modelling of the resulting ionisation and Coulomb explosion dynamics of biomolecules to optimise experimental parameters and enable correct structural reconstruction, yet simulating the complete dynamics at protein scale is beyond the reach of quantum-mechanical methods. To address this, we developed \moldstruct, a hybrid Monte Carlo/Molecular Dynamics code built on GROMACS that couples high intense X-ray ionisation dynamics modelled through a Monte Carlo module with classical Molecular Dynamics for atomic propagation. Benchmarked against quantum mechanical calculations for di-alanine, MolDStruct agrees in fragmentation patterns above a mean charge per atom of $\bar{z} \approx 1.35$. Compared with Coulomb explosion imaging experimental data for 2-iodopyridine, simulated momentum distributions reproduce the experimental Newton plots in fragment direction and

arXiv:2608.17119v1 Announce Type: new Abstract: This work applies Bayesian optimization to a loop composed of PIC simulations of laser electron acceleration and Monte Carlo (MC) simulations of bremsstrahlung-induced nuclear reactions, to maximize the production of molybdenum-99, the precursor of the most used radiopharmaceutical in nuclear medicine, metastable technetium-99. PIC and MC simulations are computationally intensive, and besides reducing the time spent, the Bayesian optimization coupling both simulations resulted in an improvement of an order of magnitude in the $^\text{99}$Mo yield over a previous work, in which the output of an optimization loop based solely on PIC simulations was used a posteriori to estimate $^{99}\mathrm{Mo}$ production through a MC simulation.

Researchers at the University of Oldenburg's Institute of Physics are working on techniques for precision control of electric fields of light, which allow the dynamics of individual electrons to be manipulated in experiments. Now a team from the Attosecond Microscopy research group, led by Dr. Jan Vogelsang, has taken a decisive step toward this goal.

arXiv:2608.16811v1 Announce Type: new Abstract: Advances in 3D laser-nanoprinting enable us to fabricate 3D nanophotonic devices with a wide range of functionalities on demand. By exploiting all three spatial dimensions, an enormous design space becomes available for these nanophotonic devices. However, such an immense design space is impossible to explore efficiently by intuition alone, especially when designing free-form nanophotonic devices. Density- based topology optimization offers a natural tool for 3D nanophotonic design by allowing the efficient design of devices with millions of degrees of freedom. Traditional density-based topology optimization relies on heuristic measures to account for limitations imposed by the fabrication method. Indeed, the fabrication method is rarely considered as part of the forward model in the design pipeline. In this work, we introduce an inverse design method that explicitly models the direct-laser-writing process used in 3D nanoprinting.

arXiv:2608.16459v1 Announce Type: new Abstract: We report on the production of ultrahigh-charge relativistic electron beams and the development of a laser-wakefield acceleration platform at the LMJ facility. Making use of the kilojoule-class, sub-picosecond PETAL laser pulse focused onto a supersonic helium gas jet, electron beams carrying a total charge beyond 1 $\mu$C were generated, with energies up to $\sim$500 MeV. Given the ps-scale laser pulse duration, an on-target intensity approaching $10^{19}~\mathrm{W/cm^2}$, and a plasma density reaching 2% of the critical density, electron energisation arises from a combination of self-modulated laser wakefield acceleration (SMLWFA) and direct laser acceleration (DLA). The resulting electron spectrum exhibits a Maxwellian-like distribution, characteristic of this mixed SMLWFA/DLA regime. The total energy carried by the electron beam is estimated to be up to 17 J, within a sub-ps duration. A broadband Joule-level photon beam was also

arXiv:2608.15272v1 Announce Type: new Abstract: The development of laser-driven proton beamlines for biomedical and radiobiological applications requires traceable dosimetry and reliable online monitoring at the irradiation point. In this work, we report the relative and absolute dosimetric commissioning of the ELIMAIA--ELIMED laser-driven proton beamline at ELI Beamlines using an energy-selected proton beam with an average energy of about 24~MeV. Radiochromic-film measurements were used to characterize the transverse dose distribution, the depth--dose profile, and the proton energy spectrum at the irradiation point. The reconstructed spectrum was centred at $23.45~\mathrm{MeV}$ with a FWHM of $2.60~\mathrm{MeV}$, while the transverse dose distribution showed an approximately $5.5~\mathrm{mm}$ field size with a millimetre-scale homogeneous region. The Faraday Cup was used as the absolute reference detector for dose to water determination and for cross-calibrating the Dual-Gap

arXiv:2608.15039v1 Announce Type: new Abstract: Laser pulses carrying orbital angular momentum (OAM) provide a new degree of freedom for controlling plasma-based accelerators. Here, we demonstrate experimentally laser wakefield acceler- ation driven by OAM laser pulses, producing electron beams with distinct broad-band energy spectra and angularly structured phase space. The measured spectra exhibit a two-beamlet structure with correlated angular dispersion, indicating injection occurring at multiple azimuthal phases of the plasma wake. Particle-in-cell simulations reproduced the observed spectral features and revealed helical electron trajectories driven by the OAM-induced wakefields. These results show that the phase structure of the laser driver can shape electron injection and acceleration dynamics, opening a route toward optimal control of beam structure in compact laser-driven accelerators.

arXiv:2608.15236v1 Announce Type: cross Abstract: Link-budget studies of indoor optical wireless systems frequently assume receiver parameter sets--large photodetector area, large transimpedance, and wide bandwidth simultaneously--that violate basic circuit constraints, and noise budgets that omit dominant amplifier and laser noise. This paper develops a realizability-constrained design-space analysis of a diffused-beam laser-diode (LD) LiFi link anchored to a hardware prototype. The analysis couples the generalized Lambertian channel of a holographic-diffuser source to a receiver model that enforces the transimpedance-amplifier gain-bandwidth/capacitance constraint and carries a complete noise budget: shot, feedback-resistor thermal, input current noise, capacitance-driven voltage-noise gain, and laser relative intensity noise (RIN). Against this budget we evaluate unipolar M-PAM under two FEC tiers (7%-overhead hard-decision at $3.8 \times 10^{-3}$, 20%-overhead soft-decision at $2

arXiv:2608.16173v1 Announce Type: new Abstract: This study proposes a relative orbit control law for laser debris removal missions considering the uncertainties of laser ablation and atmospheric drag. A removal spacecraft irradiates laser pulses to a target debris to generate the ablation force for deorbiting. The deorbiting force lowers the target altitude, and the removal spacecraft must follow it to maintain its relative position for continuous laser irradiation. The difficulty stems from uncertainties of the magnitude of laser ablation and external disturbances such as atmospheric drag. To tackle this problem, this study derives an adaptive control method using the Gaussian process regression to cancel the uncertainties with a nonparametric regression model. Numerical simulations verify the proposed control law under the uncertainties of laser ablation and atmospheric drag. The proposed control law can contribute to the realization of a safer and more secure mission not only for

For patients facing a diagnosis of glioblastoma - one of the most aggressive and devastating forms of brain cancer - the standard path forward has long meant an invasive open-skull surgery and a daunting prognosis.

arXiv:2608.14137v1 Announce Type: new Abstract: Within the framework of a stationary model of relativistic self-focusing, it is shown that the addition of a thin layer of denser plasma on the propagation axis of a circularly polarized beam increases the axial magnetic field generated by it via the inverse Faraday effect by more than a factor of 10 compared to the case of a homogeneous plasma. The magnitude of the axial field in this case can exceed the magnetic field of the laser wave, which makes it possible, at radiation intensities $\sim 10^{26}$~W/cm$^2$ potentially achievable in the near future, to approach the level of teragauss quasi-stationary fields.

arXiv:2608.13919v1 Announce Type: new Abstract: Focused very-high-energy electron (VHEE) beams can produce localized dose enhancement at selected depths, but irradiation of a finite target requires coordinated control of multiple focal positions, incidence directions, and beam weights while limiting exposure of nearby organs at risk (OARs). We present Focal-Point Scanning (FPS), a dose delivery and optimization method developed for laser wakefield accelerator (LWFA)-driven VHEE beams. The method is based on a two-dipole focusing system that produces single-plane beam convergence and allows the focal position to be varied by changing the magnetic field strength. FPS distributes focal points throughout the planning target volume and determines focal-point-specific incidence sectors according to the geometry of nearby critical OARs. The method was evaluated using the AAPM TG119 C-shape benchmark and one previously treated lung radiotherapy case. At matched target coverage, FPS reduced

arXiv:2608.13778v1 Announce Type: new Abstract: We present a pulse-shaper-based dispersion-scan (d-scan) framework for the combined generation and characterization of polarization-tailored femtosecond laser fields. By integrating a programmable $4f$ pulse shaper with polarization-resolved d-scan measurements, the framework enables the programmable synthesis and reconstruction of complex time-dependent polarization states. We demonstrate its capabilities for several classes of vector fields, including counter-rotating circularly polarized pulse pairs, oppositely chirped counter-rotating circularly polarized pulses, polarization-gate pulses, and multi-pulse sequences utilizing polynomial, periodic and discrete spectral phase functions. The reconstructed temporal electric fields and time-dependent ellipticities show excellent agreement with the simulated target fields and accurately reproduce the defining features of each pulse class. By combining the versatility of programmable pulse

arXiv:2608.12577v1 Announce Type: cross Abstract: We present the fabrication and characterization of the first silicon-platelet feedhorn arrays produced using laser micromachining. First, we present a demonstration of the technology for the millimeter-wave band of 80~GHz to 170~GHz, i.e. covering the 90/150~GHz bands typical of CMB experiments. Next, we expand the technology to large-scale production on 150~mm wafers and demonstrate operation at submillimeter wavelengths. This feedhorn array is optimized for operation in a band centered at 350~GHz (330~GHz to 370~GHz) and is being deployed as one of the focal plane elements of the CCAT 350~GHz module of Prime-Cam. We present the design and fabrication processes for these feedhorn arrays and compare the optical performance directly to simulation and to feedhorns of identical design but produced using traditional deep reactive-ion etching (DRIE). We conclude with a discussion of future expansions of this technology, including the

arXiv:2608.12943v1 Announce Type: new Abstract: Fast and wide-range wavelength switching is desirable for optical communications and photonic systems that are frequency-agile. However, thermo-optic (TO)-tuned integrated lasers often have limited switching times and tuning rates. This study demonstrates a hybrid-integrated III-V/Si3N4 external-cavity laser (ECL), combining a dual-microring Vernier filter with thermal pumping to give wide-range and fast wavelength control. The ECL provides single-mode static lasing wavelength tuning in the 1486-1614 nm range. Impulsive thermal pumping that is applied through microheaters with shorter duration and higher amplitude accelerates the switching time. A simple first-order thermal fit reproduces the measurements well, indicating that the TO-tuning dynamics are highly predictable. Consequently, two-step pulse thermal pumping is applied to the on-chip microheaters to exploit the initial quasi-linear heating transient and sustain the target

arXiv:2608.11861v1 Announce Type: new Abstract: Beam shaping has become one of the principal determinants of throughput, precision, and process robustness in ultrafast laser micromachining. Despite this, the field is still largely interpreted through a historical distinction between programmable and static optical elements, a framework that increasingly fails to explain recent advances. This review reexamines that perspective and argues that beam shaping should instead be understood as a hardware-algorithm co-design problem. Across high-power spatial light modulators, machine-learning holography, hybrid optical architectures, and massively parallel processing, recent advances converge on the same conclusion: performance depends more on the codesign of optical hardware and computational algorithms than on any individual optical component. To establish a common basis for comparison, seven beam-shaping technologies and five algorithm families are evaluated within a unified seven-axis

arXiv:2608.11664v1 Announce Type: new Abstract: Experiments at the OMEGA EP laser facility were designed and executed to study plasma expansion into hohlraum-relevant gas fills (0.3-0.6 mg/cc of helium), providing a surrogate platform for investigating hohlraum wall blow-off, non-local transport, and magnetized plasma effects. We observe well-defined density features and filamentary structures as laser-driven copper plasma expands into a low-Z background gas. Shadowgraphy resolves sharp density features over time and reveals fine-scale filamentation in the laser spot region with characteristic transverse scales of 10-100 microns near the foil surface. Proton radiography provides sensitivity to path-integrated magnetic fields and density modulations throughout the bubble volume. We extract the bubble expansion as a function of time for two gas pressures, 350 psi (producing 0.3 mg/cc equivalent conditions) and 700 psi (0.6 mg/cc equivalent conditions), and compare the measured

arXiv:2608.10943v1 Announce Type: cross Abstract: Atomic nuclei are strongly correlated quantum many-body systems, and how their shell structure evolves with increasing neutron excess remains a central open question in nuclear physics. Calcium isotopes are an ideal testing ground: alongside the traditional magic numbers $N=20,28$, new shell closures have been proposed at $N=32,34$ ($^{52,54}\mathrm{Ca}$). While the charge radius rises rapidly towards $N=32$, further moments and radii in the isotopic chain have remained inaccessible due to the low production yield of a few ions per second. Here we apply a highly sensitive collinear laser spectroscopy technique, which reveals a strikingly simple behaviour: adding one neutron to $^{52}\mathrm{Ca}$ yields a pure single-particle magnetic dipole moment in $^{53}\mathrm{Ca}$, while the charge-radius slope towards $^{54}\mathrm{Ca}$ exceeds that towards $^{52}\mathrm{Ca}$. This provides strong evidence for a robust $N=32$ shell closure and

arXiv:2608.10998v1 Announce Type: new Abstract: Stark acceleration and deceleration based techniques for generating particle ensembles with low velocity spread are useful in many experimental applications. For a given velocity distribution of a particle ensemble, these techniques accelerate or decelerate a small subset of the total population, with a low velocity uncertainty. However, narrowing the original velocity distribution by accelerating or decelerating the ensemble particles near the mean velocity is fundamentally limited and not yet explored. We present a numerical study of particle dynamics using neutral cesium atoms as an example. We investigate different interaction regimes, identify key limitations, and propose an interaction regime in which optical Stark deceleration can be used to narrow the velocity distribution of a propagating ensemble about its mean velocity. These findings have potential implications for optical manipulation and control, controlled collisions, and

arXiv:2608.10419v1 Announce Type: new Abstract: We show that the APS-U could support a hard X-ray storage ring free electron laser oscillator, providing a promising avenue toward high repetition rate, narrow bandwidth coherent light sources. The results of our numerical simulations demonstrate that a transverse gradient undulator yields ~8% and ~6% single-pass gain at 8.05 keV and 10 keV respectively. We further identify a configuration at 5 keV that does not require a TGU but still exceeds a 5% gain threshold despite the relatively short 5-meter long insertion device. All cases presented retain spectral purity on the order of meV and reach a steady-state output whose equilibrium is consistent with the Renieri Saturation Limit. We have calculated the 5 keV case to have an average brightness of ~10^26 photons/(s * mm2 * mrad2 * 0.1% BW), representing an increase in more than four orders of magnitude from the standard APS-U undulator. These results indicate that a storage ring free

arXiv:2608.09969v1 Announce Type: new Abstract: Nanosecond lasers are widely used in industrial applications as they are relatively inexpensive, and their compactness and robustness are an advantage. Much experimental work has been carried out to understand deeper the interaction between the nanosecond laser pulses and the targets, as these are complex, transient processes with spatial inhomogeneities. Beside the experiments, the modeling and numerical simulation on the laser interaction with the target are also crucial for understanding the dynamics of laser-material interactions and for optimizing laser processing applications. In this review, the progress of numerical modeling and simulation on nanosecond laser-target interactions are summarized from the aspects of laser-target interactions and target-plasma interface, laser-plasma interactions and plasma radiation, and numerical models on different scales with artificial intelligence advancing. The laser ablation, mass and energy

arXiv:2608.10950v1 Announce Type: cross Abstract: Laser diodes (LDs) promise an order-of-magnitude bandwidth advantage over light-emitting diodes for indoor optical wireless access, but reported prototype studies frequently leave the gap between hardware demonstrations and system-level performance unquantified. This paper develops a complete, reproducible system model of a diffused-beam LD LiFi transceiver - a 500-mW laser source beam-shaped by a holographic diffuser, an intensity-modulation/ direct-detection (IM/DD) receiver, and adaptive M-QAM signaling - and embeds it in two cross validated simulators: an open ns-3 module providing full-stack network simulation (channel, PHY, ARQ MAC, Net Device, IP/UDP/TCP) and a Python link-level engine used for Monte Carlo validation of all analytical error models. Starting from a hardware prototype that transferred data, real-time voice, and images over a 14-m line-of-sight link, we identify and close the technical gaps typical of

arXiv:2608.10549v1 Announce Type: new Abstract: Achieving high accuracy in laser-based cutting of optical films requires careful tuning of parameters such as focal length and laser power beam, adjusted according to the specific properties of each film type. Trial-and-error based traditional methods are used to find the most suitable cutting parameters for various films, but they are slow and inaccurate. To address this issue, this paper presents the Reinforcement Learning for Laser Cutting (RL$^{2}$C) algorithm, which uses Q-learning with an epsilon-greedy policy to dynamically optimize cutting parameters, significantly reducing taper size and film wastage. Additionally, RL$^{2}$C incorporates a dynamic environment space adaptability mechanism to allow it to adapt to new states encountered during the learning process over multiple batches of experiments. Experimental results demonstrate that RL$^{2}$C requires fewer steps and less time to find optimal cutting parameters compared to

Blum-Novotest, leading supplier of innovative and high-quality measuring and testing technology, will be presenting several product highlights for the automation of machining processes at the IMTS 2026 in Chicago, IL (Booth 134710 East Building).

arXiv:2608.09631v1 Announce Type: new Abstract: Femtosecond lasers underpin applications ranging from material processing to corneal surgery, while their regular pulse trains form optical frequency combs that have revolutionized timekeeping, spectroscopy, and metrology. On-chip optical frequency combs, such as Kerr microcombs, have enabled high-repetition-rate applications in optical communications and microwave photonics. However, integrated chip-scale sources operating at low repetition rates (100 MHz to 1 GHz), crucial for high peak intensities, remain elusive, as existing devices typically operate well beyond 10 GHz. Here, we demonstrate a self-starting, photonic integrated mode-locked laser based on a dispersion-managed architecture that accesses this regime. The laser combines erbium-implanted silicon nitride gain waveguides, integrated chirped Bragg gratings, and a semiconductor saturable absorber mirror to generate optical pulses with repetition rates from 0.5 to 1.2 GHz,

arXiv:2608.09618v1 Announce Type: new Abstract: Functional polymer surfaces with tailored wettability, antibacterial and adhesion properties are increasingly required in medical, packaging and consumer applications. Laser structuring of steel mould inserts followed by injection moulding offers a scalable manufacturing route, but conventional single-beam texturing has limited throughput. Here, we present a selective acceleration strategy that applies different laser techniques to micro- and nanostructuring. Deep microhole drilling was accelerated up to 20-fold by operating an ultrashort-pulse fibre laser at a repetition rate of 1 MHz in single-beam mode. For laser-induced periodic surface structures (LIPSS), line-beam shaping with a spatial light modulator increased productivity by 35-fold, reaching processing speeds above 100 cm$^2$ min$^{-1}$ while retaining sub-micrometre fidelity. Replication experiments with polypropylene (PP), PA66 and ABS confirmed successful transfer of micro-

arXiv:2608.09545v1 Announce Type: new Abstract: Direct laser interference patterning (DLIP) generates periodic micro- and nanoscale structures with increasing precision and throughput, yet similar geometries can produce fundamentally different functional responses. This review examines why morphology alone cannot predict friction, wetting and ice adhesion, bacterial response, cell behaviour, optical performance or electrochemical and photovoltaic function. DLIP is treated as a model system in which the optically prescribed geometry can be distinguished from the interface realised during processing. The written period is separated from relief depth, aspect ratio, hierarchical topography, surface chemistry, ageing and process history. Functional response is interpreted as a two-stage process: geometry creates the opportunity for interaction with an external agent, while the realised interface determines how that interaction becomes measurable performance under a specific interfacial

arXiv:2608.08983v1 Announce Type: new Abstract: A sodium laser guide star operated as a mesospheric magnetometer modulates a 589 nm laser at the local Larmor frequency and usually diverts a fraction of its power to a repumping light that recovers atoms lost to the dark ground state.The polarization, read out for the most strongly driven velocity group, calls for 2.8 times the flux optimal fraction, and a shot noise figure of merit combining the two observables for 2 times, beyond the range commercial guide star lasers provide.

arXiv:2608.08912v1 Announce Type: new Abstract: High-resolution laser spectroscopy of the $^{85}\mathrm{Rb}_2$, $^{85}\mathrm{Rb}^{87}\mathrm{Rb}$, and $^{87}\mathrm{Rb}_2$ isotopologues has been performed in a supersonic molecular beam using a continuous-wave (cw) tunable diode laser. A total of 958 rovibronic transitions were recorded up to $7~\mathrm{cm}^{-1}$ below the vibrational band heads of the $X^1\Sigma_g^+(v''=0)\rightarrow B^1\Pi_u(v'=1,2)$ and $X^1\Sigma_g^+(v''=1)\rightarrow B^1\Pi_u(v'=1)$ bands, with a spectral resolution of $3.3\times10^{-4}$~cm$^{-1}$. Although restricted to the $v'=1$ and $v'=2$ vibrational levels of the excited $B^1\Pi_u$ state, the measurements extend previous work by Amiot and Verg\`es [Chemical Physics Letters 274, 91 (1997)] through substantially higher resolution and dense low-$J'$ rotational data for all three isotopologues. A global least-squares analysis combining the new and published data, yields improved Dunham coefficients for the

arXiv:2608.08903v1 Announce Type: new Abstract: Laser wakefield acceleration promises compact electron accelerators for applications in medicine, industry, and fundamental science. Yet, despite rapid progress, accurately predicting the electron energy attainable in a given experimental configuration and the acceleration length required to reach it remains an open challenge. Here we use Bayesian optimization combined with advanced particle-in-cell simulation techniques to determine the maximum electron energy that a self-guided laser wakefield accelerator driven by a laser of a given energy and wavelength can produce. By systematically optimizing the accelerator performance across a range of laser energies and wavelengths, we derive energy-optimized scaling laws. These scaling laws yield the highest electron energy over the shortest acceleration length possible, are expressed solely in terms of laser energy and wavelength, and are accompanied by the complete set of laser and plasma

arXiv:2608.08586v1 Announce Type: new Abstract: Femtosecond relativistic electron beams are key probes of ultrafast dynamics, and their pulse duration directly limits the achievable temporal resolution. Laser wakefield acceleration (LWFA) provides a compact source of such beams, but the injection-induced energy spread makes bunch compression sensitive to nonlinear longitudinal transport, motivating direct longitudinal phase space (LPS) measurements. Here, a terahertz transverse-deflecting cavity (THz-TDC) combined with a dipole magnet is used to reconstruct the nonlinear LPS of LWFA electron bunches compressed in a double-bend achromat (DBA), resolving a characteristic C-shaped distribution associated with higher-order longitudinal transport. At an average energy of approximately 4.55 MeV, the diagnostic achieves a temporal resolving power of 1.8 fs and an energy resolution of 6.0 keV, corresponding to a relative energy resolution of 0.13%. For comparable energy spreads of

arXiv:2608.07308v1 Announce Type: new Abstract: On-chip frequency combs are increasingly relevant to both laser science and applications. Broad bandwidths and flat-top spectral envelopes are especially desirable for precision spectroscopy and dense wavelength-division multiplexed communications. Toward these goals, active microwave modulation has emerged as a powerful strategy for generating, stabilizing, and reconfiguring frequency combs at the source. However, practical challenges associated with high-frequency modulation imposes an upper bound on the accessible cavity free spectral ranges. Here, we demonstrate a subharmonic locking scheme in a quantum walk comb laser, a recently introduced platform for broadband and highly controllable comb states. Using a THz ring quantum cascade laser, we realize quantum walk comb formation under strong microwave injection at successive subharmonics of the cavity round-trip frequency, tuning the comb spacing from 15.8 to 1.58 GHz. The resulting

In a new Nature Physics study, researchers accelerated electrons to more than twice the energy predicted by the traditional dephasing limit for laser-plasma accelerators operating over the same distance. This was made possible by a specially engineered laser pulse called a flying focus, which counteracts a longstanding limitation known as "dephasing."

For the first time, researchers have determined the shape of the actinide nucleus of fermium-255 and measured its structure with high precision and resolution.

arXiv:2608.06169v1 Announce Type: new Abstract: Compact cesium beam clocks are major frequency references for deployable timing systems. However, further improvement of their short-term frequency stability is limited by the clock signal-to-noise ratio (SNR). Although two-laser optical pumping can increase the effective atomic utilization, the achievable clock SNR has long been limited by laser-induced frequency-to-amplitude noise conversion. Here, we demonstrate a compact dual-Faraday-laser-pumped (DFP) Cs beam clock enabled by a low-frequency-noise atom-referenced laser architecture. The intracavity Faraday anomalous dispersion optical filter provides inherent alignment to the Cs D$_2$ resonances, while modulation transfer spectroscopy offers suppressed frequency noise and drift. The resulting laser system supports robust turnkey operation with a Lorentzian linewidth of 2.12 kHz. The DFP Cs clock achieves a clock SNR of 46,365 in a 1-Hz bandwidth and a fractional Allan deviation of

arXiv:2608.06160v1 Announce Type: new Abstract: We present a formulation and numerical results for positronium (Ps) laser cooling. The formulation is based on the Lindblad master equation and follows the time evolution of the density matrix of Ps atoms. It therefore accounts for atomic coherence, which is necessary to describe the interaction of Ps with the train of short laser pulses generated by the system developed by Shu $\textit{et al.}$ [K. Shu $\textit{et al.}$, Phys. Rev. A $\textbf{109}$, 043520 (2024)]. Using this formulation, we calculate the time evolution of the populations in each internal and momentum state and thereby quantitatively predict the momentum distribution after laser cooling. We present the representative time evolution of the internal-state populations and momentum distribution, together with a comprehensive scan of the laser parameters used to optimize the cooling efficiency. A prominent feature of the simulated distributions is sub-recoil cooling through

arXiv:2608.06138v1 Announce Type: new Abstract: Cold heavy molecules are promising systems for exploring nuclear $\mathcal{P}$- and $\mathcal{CP}$-violating phenomena in search of new physics beyond the Standard Model. However, most proposed experimental strategies and their early realizations to date have been limited to proof-of-principle molecular species with effectively spin-zero nuclei that are not sensitive to nuclear symmetry-violating phenomena. Here, we introduce a comprehensive experimental toolbox that integrates cooling, trapping, coherent state manipulation, and a complete precision-measurement protocol that is applicable to molecules carrying relevant nuclear spins. Using ${}^{137}$Ba${}^{19}$F and nuclear-spin-dependent parity violation (NSD-PV) as representative species and benchmark application, respectively, our approach achieves a projected statistical sensitivity roughly two orders of magnitude beyond comparable molecular beams by combining techniques already

arXiv:2608.05773v1 Announce Type: new Abstract: A geometry-conditioned, neuro-symbolic closed-loop architecture is proposed for laser powder bed fusion, in which a standards-aligned ontology operates inside the control loop and couples symbolic reasoning with statistical learning to set the targets of a constraint-aware predictive controller. The ontology links the process objectives and constraints to the signals a controller can observe, and a description-logic reasoner converts them into the references and bounds enforced on each scan. The demonstrated case is overhang dross, a quality limit on the melt pool depth, which governs quality yet cannot be measured during the build, is mapped through a geometry- and power-dependent depth-to-width ratio onto a bound on the observable width, with the ratio and its calibrated uncertainty supplied by a Gaussian process. The reasoner classifies each upcoming feature and selects the active constraints-adding a lack-of-fusion floor at

Researchers have demonstrated a solid-state organic laser microcavity fabricated entirely by solution processing. The device operates in the strong light–matter coupling regime, where light and matter form hybrid states called polaritons. This makes the platform not only a new type of solution-processed laser but also a powerful way to study nonlinear polariton interactions. The paper is published in the journal Nature Communications.

arXiv:2608.05073v1 Announce Type: new Abstract: Existing patterning processes for organic light-emitting diode displays offer micrometer-scale precision but are constrained by long processing times for large-area substrates. In this work, we study a fast growth method for patterned organic film deposition, aimed at applications including active-matrix organic light-emitting diode displays. The approach employs a specially engineered donor substrate in a close-space sublimation configuration combined with laser heating. The donor substrate incorporates spatially patterned absorber and reflector layers that enable selective, one-step or two-step transfer of organic material onto a receiver substrate. We analyze the optical response and heat-transfer dynamics that govern the selective transfer mechanism and demonstrate precise pixel patterning with micrometer-scale spatial fidelity. The reliability and practical applicability of the method are validated by fabricating light-emitting

arXiv:2608.04699v1 Announce Type: new Abstract: We propose a chirped-pulse injection scheme into a hard x-ray low-emittance synchrotron light source such as PETRA IV from a laser-plasma electron injector with active energy compression. The scheme enables delivering kA-scale short pulses with several tens of hertz repetition rate to any synchrotron beamline in the ring and allows producing femtosecond temporally coherent radiation pulses at target beamlines.

arXiv:2608.04517v1 Announce Type: new Abstract: It is shown that the convective gain of Stimulated Raman Backscatter (SRBS) within a single laser wavelength in the strongly coupled regime is equivalent to the Pierce parameter commonly used to describe high gain x-ray Free Electron Lasers (XFELs). The comparison utilizes the fact that the gain is a Lorentz invariant so the Pierce parameter is written in terms of the FEL parameters in the electron beam's rest frame. It is thus inferred that there is a direct correspondence of the physics between SRBS in the strong-coupled regime and high gain XFELs in the Compton regime.

arXiv:2608.04363v1 Announce Type: new Abstract: Linearly polarized attosecond $\gamma$-ray pulses in the MeV range are generated from a cone target irradiated by a single few-cycle laser pulse. Electron layers are periodically extracted from the cone walls and subsequently accelerated. Their interaction with the counter-propagating reflected attosecond field produces high-energy photons through nonlinear Compton scattering (NCS), forming attosecond $\gamma$-ray pulses. We model this interaction using two-dimensional quantum electrodynamics particle-in-cell (QED-PIC) simulations that resolve electron spin and photon polarization during emission. The results show a shortest equivalent duration of $300\,\mathrm{as}$, with a corresponding linear polarization degree of 0.78. The photon spectrum extends to $6\,\mathrm{MeV}$, and the linear polarization degree in the high-energy range reaches 0.88. The linear polarization degree remains high when photons from both emission directions are

An international team of researchers has succeeded in producing atomic quantum gas mixtures with an unprecedented particle flux. In the journal Nature Communications, the scientists report on experiments conducted with the MAIUS-B apparatus, in which Bose–Einstein condensates (BECs) consisting of two different atomic species—rubidium and potassium—were generated and studied under microgravity conditions in the Einstein Elevator at Leibniz University Hannover in Germany.

For the first time, a group of biologists and engineers from the University of São Paulo (USP) in Brazil applied LiDAR (light detection and ranging) technology to investigate the health of trees and optimize pruning with the aim of reducing the risk of trees falling. This laser-sensing technology creates a "point cloud," a kind of 3D digital mold consisting of millions of coordinates that reproduces the plant's exact architecture in a computer.

arXiv:2608.03969v1 Announce Type: new Abstract: A Thomson parabola ion spectrometer (TPIS) has been designed and developed for diagnostics of laseraccelerated ion beams in the MeV energy range. The TPIS has been validated by ion acceleration experiment at petawatt laser facility. Necessary simulations to evaluate the electric and magnetic field distributions have been performed with the help of a numerical simulation software to aid the selection of the spectrometer geometry while minimising fringe-field effects. Analytical dispersion expressions have been formulated from the simulations that take into account the spatial variation in the electromagnetic field profiles. The ion deflections obtained from these expressions demonstrate an improved agreement with experimentally measured proton trajectories compared to the case when constant fields are considered. The TPIS hence fabricated in-house has been subject to magnetic field measurements, which are in excellent agreement with the

arXiv:2608.03814v1 Announce Type: new Abstract: 4H-SiC has emerged as a third-generation chip material because its superior thermal conductivity and high breakdown field enable the material to achieve high power density and higher switching frequencies in power-electronics applications. As chip architectures evolve toward 3D and heterogeneous integration, the mechanical and thermal design space tightens while yield risks grow. In particular, advanced packages require mid-process wafer thinning to

arXiv:2608.03547v1 Announce Type: new Abstract: High-power laser sources that exhibit low relative intensity noise and allow simultaneous dynamic control of their light level are required for a broad range of applications in various fields of physics. Acousto-optic modulators (AOMs) are widely used for active power stabilization and regulation due to their simple drive electronics requirements and high optical power handling capability in free-space. However, the rather slow propagation speed of the sound wave within the AOM crystal typically limits their control bandwidth to a few hundred kHz. In this work, we present a novel AOM-based control system that is capable of significantly suppressing intensity noise of high-power lasers up to the MHz range. By combining two standard feedback loops with one feedforward control branch and optimizing the beam path in the AOM crystal, ultra-low relative intensity noise levels down to $-155\, \text{dB}\,\text{Hz}^{-1}$ even at several hundred

arXiv:2608.03331v1 Announce Type: new Abstract: We present a generation-resolved analysis of shower-type, spin- and polarization-dependent quantum electrodynamics (QED) cascades initiated by head-on collisions of ultraintense laser pulses ($a_0 = 200$--$1000$) with $10$~GeV electron bunches. Using a Monte Carlo model that tracks cascade evolution across distinct generations, we shows that radiation reaction strongly suppresses high-generation yields. The positron energy spectrum exhibits a systematic softening with increasing $a_0$, and the average photon polarization $\overline{\xi}_3$ increases with pulse duration $\tau$ due to polarization-selective depletion in nonlinear Breit--Wheeler pair production. We identify a scaling relation $a_0^2\tau$ that governs both the maximum cascade generation $G_{\max}$ and the fraction of backward-emitted photons $F_r$, thereby establishing experimentally accessible diagnostics for laser intensity and pulse duration using two observables: $F_r$

arXiv:2608.03240v1 Announce Type: new Abstract: In multi-petawatt laser plasma accelerators, achieving high-density relativistic electron beams is typically accompanied by large transverse divergence, limiting the attainable effective electron density needed for high-flux interaction regimes relevant to laboratory astrophysics. Here we report experimental demonstration of self-generated magnetic pinching (SMP), a collective mechanism that actively regulates transverse beam dynamics using a Laguerre-Gaussian laser at strong relativistic intensity (~8 x 10^19 W/cm^2) interacting with an underdense plasma. The electron beam evolves from a two-lobe high-charge injection structure into a compressed, high-density profile, yielding a threefold reduction in divergence and nearly an order-of-magnitude enhancement in effective beam density compared with a Gaussian driver. Particle-in-cell simulations agree with the experimental observations and reveal that a self-generated azimuthal magnetic

arXiv:2607.29407v1 Announce Type: new Abstract: Brownian noise in the thin-film mirror coatings of optical reference cavities is a fundamental limitation in precision metrology, including gravitational-wave detectors and optical atomic clocks. We demonstrate a monolithic fused silica resonator that eliminates the use of thin-film coatings by operating via total internal reflection (TIR), achieving a finesse of 1225 and an optical mode volume of \qty{50}{mm^3}. To our knowledge, this is the largest mode volume reported for any coating-free monolithic resonator, comparable to state-of-the-art reference cavities. We use the cavity to frequency-stabilize an Nd:YAG laser, and demonstrate its application to precision metrology by operating it in a passive ring gyroscope configuration. This platform circumvents the dominant noise source of conventional reference cavities and provides a pathway toward cryogenic silicon TIR resonators that could surpass current frequency stabilization limits.

Researchers in the lab of Sam Peng, the Pfizer Inc.–Gerald Laubach Career Development Assistant Professor of Chemistry at MIT and a core institute member of the Broad Institute of MIT and Harvard, have developed a super-resolution imaging technology. It allows scientists to visualize molecular structures with angstrom-level localization precision—three orders of magnitude beyond the nanometer-scale limits of standard fluorescent dyes—while simplifying the imaging process.

arXiv:2607.26965v1 Announce Type: new Abstract: Accurate evaluation of mechanical properties in steels under ageing or service conditions remains a major challenge. We propose a thermo-mechanical coupling framework for nanosecond laser ablation based on energy conservation, which is embedded into a physics-informed neural network (PINN) to enable simultaneous inversion of multiple mechanical properties. A thermo-mechanical coupling coefficient is defined to uniformly describe the dynamic allocation of input laser energy among thermal diffusion, mechanical work and plasma shielding across different deformation stages under laser irradiation. Furthermore, hard-to-measure physical characteristics in the coupled equation are replaced with experimentally accessible features obtained through the simultaneous acquisition of spectroscopic, shockwave and surface-wave signals. Using 210 experimental datasets, the framework simultaneously recovers Young's modulus, yield strength, ultimate

arXiv:2607.26252v1 Announce Type: new Abstract: Achieving significant energy gain in laser-driven relativistic electron beams remains challenging due to dephasing between the accelerating laser field and the electrons. We show that transverse electric fields, when aligned with the plane of laser polarization, can mitigate dephasing and enable substantial energy gain without compromising beam directionality. As a practical realization, we propose a two-laser scheme in which one laser generates the transverse field while the other drives electron acceleration. By tailoring the interaction geometry, this configuration sustains phase locking, enhances energy transfer, and opens a pathway toward compact, high-efficiency electron accelerators.

arXiv:2607.26081v1 Announce Type: new Abstract: The interaction of nanosecond laser pulses with metallic materials involves multiple complex physical processes. It is challenging to construct a self-consistent model capable of uniformly describing all stages. This work establishes a multi-physics coupling model for pure iron, encompassing laser energy deposition, solid-liquid phase transition, gas-liquid interfacial kinetic transport, plasma expansion and ionization, and spectral radiation. The numerical solution adopts a partition method, utilizing an implicit compact difference scheme for the target and a Mac-Cormack explicit scheme for the plasma. The simulations elucidate the emergence of plasma shielding and its inhibitory effect on the evaporation process, thereby confirming that 81.6% of the early-stage ablation products are transported through a supersonic expansion mode. The model successfully captures the complete evolution of the plasma plume from a high-temperature, highly

Resolving a long-standing problem in semiconductor physics and optoelectronics, a team of researchers from Skoltech—a VEB.RF group institution—and their colleagues from ITMO University and HSE University have for the first time demonstrated direct electrical pumping of a polariton laser based on a solution-processed halide perovskite microcrystal. Published in Nature, this solution to a decades-long technological challenge ushers in inexpensive nonepitaxial laser diodes operating under continuous electric current. These could be used in optical sensing and spectroscopy, high-speed computing and energy-efficient neuromorphic computing.

arXiv:2607.25713v1 Announce Type: cross Abstract: Phase change Ge_Sb_Te (GST) materials exhibit pronounced optical contrast and tunability driven by structural transformations, enabling a diverse range of photonic and optoelectronic applications. GST materials undergo reversible amorphous crystalline phase transitions during which the refractive index and extinction coefficient increase significantly in the crystalline phase across a broad spectral range. However, a systematic correlation between local composition, crystalline microstructure, and broadband optical response within as deposited crystalline GST films has not been established, particularly for films spanning various compositions within a single growth process and in the absence of amorphous-crystalline transitions. Here, we report a systematic study of composition resolved optostructural property relationships in as-deposited crystalline GST films spanning Ge3Sb2Te6, Ge2Sb2Te5, and GeSb2Te4 within a single CVD process,

arXiv:2607.25856v1 Announce Type: new Abstract: Laser-driven X-ray sources produce broadband radiation with substantial shot-to-shot fluctuations, requiring calibrated detector-response models for quantitative measurements of photon fluence and spectral distribution. Scintillator-based flat-panel detectors, originally developed primarily for medical and industrial X-ray imaging, are increasingly being adopted for diagnostics of laser-plasma-based X-ray sources because they provide large-area, spatially resolved detection. We report the calibration of two complementary X-ray detector systems: a CsI:Tl-based flat-panel detector and a plastic-scintillator filter-stack spectrometer intended for spectral reconstruction. Both detectors were characterized using well-defined ISO 4037 N-series reference radiation qualities, providing controlled polychromatic X-ray fields for establishing their signal response and signal-to-fluence conversion.

arXiv:2607.25843v1 Announce Type: new Abstract: Laser power beaming offers a route to space energy delivery, but semiconductor laser photovoltaic receivers face thermalization, joule heat, and radiative recombination waste, etc. Here we propose a gas-phase plasma power cell that converts vacuum-ultraviolet photons into electrical output through xenon photoionization and magnetically biased charge separation. Particle-in-cell Monte Carlo simulations of a low-pressure xenon chamber driven by a 58.4 nm pulsed laser predict a steady-state laser-to-electrical conversion efficiency of 82.25% at 2000 W/m2 average incident power. Energy accounting closes to 1%, with 7.52% photon escape, 8.95% boundary loss, and 1.29% chamber-stored energy. Parameter scans over bias voltage, magnetic field, and gas pressure identify photon absorption and electron confinement as controlling design factors. These results are a proof-of-concept gas-phase receiver architecture for space laser power beaming.

arXiv:2607.25768v1 Announce Type: new Abstract: Laser-induced reduction of graphene oxide (GO) represents a highly promising route to graphene synthesis, offering spatially localized processing, elimination of hazardous chemical reagents, and compatibility with ambient conditions. Here, we introduce a stepwise laser reduction strategy employing a 532 nm pulsed laser, monitored in real-time by in situ dynamic transmission electron microscopy (DTEM). By systematically varying the pulse sequence and the cumulative photon and electron dose, complete deoxygenation of GO is achieved while preserving film integrity. Core-loss EELS confirms full removal of oxygen functional groups and restoration of the sp$^2$ graphitic network, evidenced by a ${\pi}^*-{\sigma}^*$ energy separation of 7.0 eV, in close agreement with graphite (7.1 eV). Crucially, the cumulative electron dose is identified as an active parameter governing the reduction mechanism: electron beam exposure accounts for

arXiv:2607.25264v1 Announce Type: new Abstract: High-power laser systems increasingly rely on multi-beam processing to enhance manufacturing throughput. However, conventional multifocal systems remain constrained by bulky architectures, stringent alignment requirements, and susceptibility to laser-induced degradation under intense irradiation. Here, we demonstrate a monolithic multifocal diamond metalens with a 7.2 mm aperture that maintains exceptional thermal stability and power tolerance. The device employs high-aspect-ratio truncated-cone diamond nanopillars to generate two focal spots separated by 200 {\mu}m at a focal length of 4 mm. Under sustained 25 W pulsed-laser irradiation for 1 h, the diamond metalens exhibits a focal shift of only 25.5 {\mu}m, resulting in a maximum processing-depth variation of 33.2 {\mu}m during 4H silicon carbide (SiC) laser scribing, far below the 319.1 {\mu}m deviation observed for a commercial objective lens combined with a beam-splitting

arXiv:2607.25235v1 Announce Type: new Abstract: The early satellites of the third-generation BeiDou Navigation Satellite System (BDS-3) are approaching the end of their design lifetime, making progressive constellation replacement an inevitable engineering task. Meanwhile, laser inter-satellite links (LISLs) provide high-precision time transfer, sub-millimeter-level ranging, and high-rate data forwarding capabilities, offering a promising upgrade path for future BeiDou satellites. This paper investigates the replacement-sequence planning problem for progressively replacing legacy microwave satellites with laser-enabled satellites from a networking perspective. To address this problem, three main contributions are made: (i) BeiDou progressive replacement is formulated as a network-aware launch sequence planning problem over evolving laser--microwave hybrid constellation states; (ii) an integer linear programming (ILP) model is developed to evaluate the networking gain of each candidate

Scientists have created twisted laser beams that interact differently with right-handed and left-handed molecules, revealing their identity through the fragments they produce. The approach could provide a faster, simpler, and more sensitive way to analyze important molecules used in chemistry and pharmaceuticals.

Scientists have created an “electron lighthouse” that uses laser light to launch and steer electrons through a semiconductor without an applied electrical field. The quantum effect could eventually improve optical sensors, communications, imaging, and information storage.

arXiv:2607.24240v1 Announce Type: new Abstract: In this work, we demonstrate an ultra-narrow linewidth self-injection locked distributed feedback (DFB) diode laser emitting at 452 nm, achieving an intrinsic linewidth of 170 Hz with a fiber output power of 11 mW. The linewidth reduction of the DFB laser is obtained thanks to the coupling with an external cavity based on a fiber Bragg grating (FBG). Experimental results demonstrate excellent agreement with our theoretical modeling of the self-injection dynamics. Furthermore, the tuning capabilities of the system are characterized, with tunability achieved via current modulation, yielding a tuning efficiency of 300 MHz/mA over a continuous mode-hop-free range of 600 MHz. This architecture offers a robust pathway toward an integration within a compact package. Ultimately, such compact, stable, and frequency-tunable visible light sources are key for integrated optical atomic clocks and underwater lidar application.

arXiv:2607.23288v1 Announce Type: new Abstract: Photonic reservoir computing is a promising physical machine-learning technique for predicting time-series data. The quantization of the response signal from the reservoir is required for the implementation of photonic reservoir computing, and the number of quantization bits and sampling frequency need to be optimized to achieve high performance and low energy consumption. However, few studies have been reported to investigate the effect of bit quantization and sampling frequency. In this study, we introduce a concept of approximate reservoir computing with a semiconductor laser by quantizing the amplitude of node states in the reservoir and output weights. We evaluate the performance of a chaotic time-series prediction task and energy consumption per sample. We achieve significant reduction of energy consumption by optimizing the number of quantization bits, the sampling frequency, and the injection current of the semiconductor laser,

arXiv:2607.23288v1 Announce Type: cross Abstract: Photonic reservoir computing is a promising physical machine-learning technique for predicting time-series data. The quantization of the response signal from the reservoir is required for the implementation of photonic reservoir computing, and the number of quantization bits and sampling frequency need to be optimized to achieve high performance and low energy consumption. However, few studies have been reported to investigate the effect of bit quantization and sampling frequency. In this study, we introduce a concept of approximate reservoir computing with a semiconductor laser by quantizing the amplitude of node states in the reservoir and output weights. We evaluate the performance of a chaotic time-series prediction task and energy consumption per sample. We achieve significant reduction of energy consumption by optimizing the number of quantization bits, the sampling frequency, and the injection current of the semiconductor laser,

arXiv:2607.22725v1 Announce Type: new Abstract: Data augmentation is routinely used to improve generalization in image classification, but the assumptions underlying standard policies are poorly matched to coherent imaging. Laser speckle patterns are not generic textures; they arise from coherent interference, and their discriminative content is carried by structured stochastic spatial and frequency statistics. This study examines how controlled augmentation perturbations influence speckle-based material classification on the SensiCut dataset. We train ResNet18 and EfficientNet-B0 under a parametric augmentation framework comprising rotation, Gaussian blur, independent Gaussian noise, spatially correlated speckle-aware noise, intensity jitter, and spatial masking, and evaluate test performance using macro F1-score averaged over three random seeds. Separate ordinary least squares models link augmentation parameters to performance for each architecture. Across both models, Gaussian blur

Laser dicing, a technique that uses focused laser pulses to separate individual chips from a semiconductor wafer, is increasingly favored over mechanical blade cutting because it can process delicate, low-strength materials with minimal physical stress. However, achieving proper yield requires precise control over the process.

arXiv:2607.21830v1 Announce Type: new Abstract: Recently, the possibility of LPA-produced muon beams has gained significant interest within the accelerator application community. Directional, multi-GeV muons can be produced via Bethe-Heitler interactions when multi-GeV electrons hit solid targets. They are highly penetrating and, thanks to the compactness of the LPA, offer a path toward a deployable, active muon source. At the BELLA Center of the Lawrence Berkeley National Laboratory, we previously unambiguously detected muons generated during the interaction of multi-GeV electron beams with a 4 meter-thick electron beam dump. A new campaign has now extended our diagnostic capabilities to single-muon trajectory reconstruction and energy measurements. The setup allowed us to individually reconstruct each muon trajectory, defined by us as a muon passing through three detectors used for the reconstruction. For a subset of events, we extracted the muon energy from the magnetic-field