Abstract Interactions between light and matter during short-pulse laser materials processing are highly nonlinear, hence acutely sensitive to parameters such as the pulse energy, repetition rate, number of pulses used. Due this complexity, simulation approaches based on calculation underlying physical principles can often only provide a qualitative understanding inter-relationships these parameters. An alternative approach parameter optimisation, requires systematic time-consuming...

Coherent beam combination of multiple fibres can be used to overcome limitations such as the power handling capability single fibre configurations. In a scheme, focal intensity profile is critically dependent upon relative phase each and so precise control over channel essential. Determining required compensations from alone (as measured via camera) extremely challenging with large number information obfuscated. Whilst iterative methods exist for retrieval, in practice, due noise within...

Abstract A neural network was trained to generate synthetic images of severe and moderate psoriatic plaques, after being on 375 photographs patients with psoriasis taken in a clinical setting. latent w-space vector identified that allowed the degree severity generated be modified. second size plaque modified this used show potential alleviate bias training data. With appropriate data, such an approach could see future application setting where patient is able observe prediction for...

Abstract Whilst advances in lasers now allow the processing of practically any material, further optimisation precision and efficiency is highly desirable, particular via development real-time detection feedback systems. Here, we demonstrate application neural networks for system monitoring visual observation work-piece during laser processing. Specifically, show quantification unintended beam modifications, namely translation rotation, along with closed-loop capable halting immediately...

Coherent soft x rays are produced by high-harmonic generation in a capillary filled with Ar gas. We demonstrate that the tuning of harmonic wavelengths intensity and chirp arises from changes ionization level. Control over can be achieved either changing average laser pulse or varying quadratic spectral phase pulse. observe an ionization-dependent blueshift fundamental wavelength is directly imprinted on wavelengths. The shown to depend nonlinear shifts due plasma created ionization, rather...

A series of nanoparticles was prepared by functionalizing a commercial nanosilica with alkylsilanes varying alkyl tail length, from propyl to octadecyl. By using constant molar concentration silane, the density groups attached each system should be comparable. The effect chain length on structure resulting nanosilica/polyethylene nanocomposites examined and comparison an unfilled reference revealed that, other than through weak nucleating effect, inclusion does not affect matrix structure....

A series of polyethylene-based nanocomposites was prepared, utilizing silicon nitride or dioxide (silica) nanopowders, and the effect filler loading conditioning (i.e., water content) on their morphology electrical properties examined. The addition nanosilicon led to systems that were free obvious nanoparticle aggregates, whereas nanosilica-based showed evidence aggregation up micrometer scale. While composites remained essentially dry under ambient conditions, absorbed appreciable...

The effect of moisture content on the dielectric properties polymer/nano-silica blends was investigated. It found that DC breakdown strength, electrical conductivity and complex permittivity were all strongly influenced by absorbed water. However, a control sample without nano-silica largely unaffected changes in content. This has important implications for researchers cable designers.

Abstract The identification of mixtures particles in a solution via analysis scattered light can be complex task, due to the multiple scattering effects between different sizes and types particles. Deep learning offers capability for solving problems without need physical understanding underlying system, hence an elegant solution. Here, we demonstrate application convolutional neural networks concentration microparticles (silicon dioxide melamine resin) salinity, directly from light....

Laser-induced backward transfer (LIBT) has been demonstrated as a viable technique for precise, localised deposition of microscale regions graphene. Single femtosecond laser pulses, shaped spatially using digital micromirror device (DMD), were incident on pre-prepared sample graphene-coated nickel (the donor substrate) through transparent glass receiver substrate. Under optimal exposure conditions, and in low-pressure gas environment, circular graphene with approximately 30 µm diameter...

Coherent beam combination offers a solution to the challenges associated with power handling capacity of individual fibres, however, combined intensity profile strongly depends on relative phase each fibre. Optimal necessitates precise control over fibre channel, determining required compensations is challenging because information typically not available. Additionally, presence continuously varying noise in laser systems means that single-step and high-speed correction process required. In...

This work combines two existing technologies to demonstrate the possibility for automated, targeted, phototherapy of psoriasis and other skin conditions: 1) Image-to-image translation via a neural network (NN) as method image segmentation. 2) Light control using digital micromirror device (DMD). With small dataset just 104 patient photographs (labeled by expert dermatologists) our NN model was trained identify regions that required treatment, achieving an average accuracy 96.6%. The output...

A microscopic magnetic quadrupole trap for neutral atoms has been realized with a combination of permanent magnets, coils, and ferromagnetic pole pieces. The attainable field gradients $3\ifmmode\times\else\texttimes\fi{}{10}^{5}\phantom{\rule{0ex}{0ex}}\mathrm{G}/\mathrm{cm}$ infer spatial extension the ground state much smaller than wavelength optical transitions. gradient can be varied over wide range which allows efficient loading $4\ifmmode\times\else\texttimes\fi{}{10}^{5}$ lithium...

Logically, the surface chemistry of filler particles must be a key factor that governs how they interact with polymer matrix, determining for example, strongly are bound into matrix and easy or difficult it is to achieve homogenous dispersion particles. This second point surely one most basic challenges when producing nanocomposite (poor frequently stated as cause undesirable results). Many attempts have been made modify through functionalization. Typically, this achieved by chemically...

Particle dispersion, water absorption/desorption and electrical breakdown behavior were studied in a range of polyethylene composites having common matrix morphology. Three different conditioning routes (dry, ambient wet) used to vary the absorbed content. Systems employing oxide fillers (silica alumina) found have poor or intermediate levels particle dispersion could absorb/desorb significant amounts water. Consequently, they required drying provide strengths comparable that host matrix....

We report the experimental realization of glass nanofibers by electrospinning directly from a melt, demonstrating viability fibers non-polymer materials with high melting temperatures and higher surface tensions. The nanofiber material (B2O3) is molten on tip gold wire, voltage applied to causes jet form, resulting in solid diameters ∼100 nm.

A series of polyethylene nanocomposites was prepared utilizing aluminum nitride or alumina nanopowders with comparable morphologies. These were subsequently subjected to different conditioning regimes, namely prolonged storage in vacuum, the ambient laboratory environment water. The effect filler loading and (i.e., water content) on their morphological dielectric properties then examined. Measurements indicated that, case nanocomposites, none regimes led significant absorption and, as such,...

Abstract We demonstrate the capability for identification of single particles, via a neural network, directly from backscattered light collected by 30-core optical fibre, when particles are illuminated using mode fibre-coupled laser source. The network was shown to be able determine specific species pollen with ∼97% accuracy, along distance between end sensing fibre and an associated error ±6 μ m. ability classify has potential in environments which transmission imaging is neither possible...

Laser cutting is a materials processing technique used throughout academia and industry. However, defects such as striations can be formed while cutting, which negatively affect the final quality of cut. As light-matter interactions that occur during laser machining are highly non-linear difficult to model mathematically, there interest in developing novel simulation methods for studying these interactions. Deep learning enables data-driven approach modelling complex systems. Here, we show...

Laser processing techniques such as laser machining, marking, cutting, welding, polishing and sintering have become important tools in modern manufacturing. A key step these processes is to take the intended design convert it into coordinates or toolpaths that are useable by motion control hardware result efficient with a sufficiently high quality of finish. Toolpath can require considerable amounts skilled manual labor even when assisted proprietary software. In addition, blind execution...

Four polyethylene based nano-composites containing either silica or silicon nitride were prepared. After verifying their compositions and morphologies, dielectric properties followed as a function of conditioning (absorbed water content). The loss DC breakdown strength found to be strongly dependent on whilst the control sample (with no nano-filler) invariant. Under ambient conditions, provides composite with reduced increased compared an analogous system employing silica. Silicon systems...

Image reconstruction of pollen grains was performed using neural networks, from light scattering patterns recorded with simultaneous irradiation at three laser wavelengths. The shapes the reconstructed optical images one network were shown to have a pixel accuracy on average 98.9%. Two other networks be able convert into predictions z-stack maximum intensity projection microscope and scanning electron microscopy images. capability producing magnified in variety formats directly will...

The effects of functionalizer chain length and water content were explored in a series polyethylene/silica nanocomposites. Silane molecules with differing lengths (propyl, octyl octadecyl) used to vary the nanoparticle surface chemistry, while vacuum drying immersion extract from or add samples previously equilibrated under ambient conditions. Electrical conductivity was found be highly dependent upon as space charge distributions. Both interfacial conditions overall transport through sample...

The response of adult human bone marrow stromal stem cells to surface topographies generated through femtosecond laser machining can be predicted by a deep neural network. network is capable predicting cell statistically significant level, including positioning predictions with probability P < 0.001, and therefore used as model determine the minimum line separation required for alignment, implications tissue structure development engineering. application network, model, reduces amount...