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Among the fascinating phenomena observed in two-dimensional (2D) magnets, the magneto-exciton effect stands out as a pivotal link between optics and magnetism. Although the excitonic effect has been revealed and exhibits a considerable correlation with the spin structures in certain 2D magnets, the underlying mechanism of the magneto-exciton effect remains underexplored, especially under high magnetic fields. Here we perform a systematic investigation of the spin-exciton coupling in 2D antiferromagnetic NiPS3 under high magnetic fields. When an in-plane magnetic field is applied, the exceptional sharp excitonic emission at ~1.4756 eV exhibits a Zeeman-like splitting with g ≈ 2.0, experimentally identifying the exciton as an excitation of dominant triplet-singlet character. By examining the polarization of excitonic emission and simulating the spin evolution, we further verify the correlation between excitonic emission and Néel vector in NiPS3. Our work elucidates the mechanism behind the spin-exciton coupling in NiPS3 and establishes a strategy for optically probing the spin evolutions in 2D magnets. NiPS3, a van der Waals antiferromagnet exhibits exciton emission with a very sharp linewidth. The exact origin of this is has been a subject of active debate. Here, Wang et al study the behavior of this sharp exciton peak under applied magnetic fields, and find a Zeeman-like splitting, indicating the exciton has triplet-singlet character. [ABSTRACT FROM AUTHOR]

Spatiotemporal structured light has opened up new avenues for optics and photonics. Current spatiotemporal manipulation of light mostly relies on phase-only devices such as liquid crystal spatial light modulators to generate spatiotemporal optical fields with unique photonic properties. However, simultaneous manipulation of both amplitude and phase of the complex field for the spatiotemporal light is still lacking, limiting the diversity and richness of achievable photonic properties. In this work, a simple and versatile spatiotemporal holographic method that can arbitrarily sculpt the spatiotemporal light is presented. The capabilities of this simple yet powerful method are demonstrated through the generation of fundamental and higher-order spatiotemporal Bessel wavepackets, spatiotemporal crystal-like and quasi-crystal-like structures, and spatiotemporal flat-top wavepackets. Fully customizable spatiotemporal wavepackets will find broader application in investigating the dynamics of spatiotemporal fields and interactions between ultrafast spatiotemporal pulses and matters, unveiling previously hidden light-matter interactions and unlocking breakthroughs in photonics and beyond. The authors showcase a spatiotemporal holographic method that can arbitrarily sculpt spatiotemporal light by generating various spatiotemporal wavepackets. The ability to deploy these fully customizable wavepackets opens up exciting avenues for their use in broader applications. [ABSTRACT FROM AUTHOR]

Materials that provide dynamically tunable infrared (IR) response are important for many applications, including active camouflage and thermal management. However, current IR-tunable systems often exhibit limitations in mechanical properties or practicality of their tuning modalities, or require complex and costly fabrication methods. An additional challenge relates to providing compatibility between different spectral channels, such as allowing an object to be reversibly concealed in the IR without making it appear in the visible range. Here, we demonstrate that conducting polymer-cellulose papers, fabricated through a simple and cheap approach, can overcome such challenges. The papers exhibit IR properties that can be electrochemically tuned with large modulation (absolute emissivity modulation of 0.4) while maintaining largely constant response in the visible range. Owing to high ionic and electrical conductivity, the tuning of the top surface can be performed electrochemically from the other side of the paper even at tens of micrometer thicknesses, removing the need for overlaying electrode and electrolyte in the optical beam path. These features enabled a series of electrically tunable IR devices, where we focus on demonstrating dynamic radiative coolers, thermal camouflage, anti-counterfeiting tags, and grayscale IR displays. The conducting polymer-cellulose papers are sustainable, cheap, flexible and mechanically robust, providing a versatile materials platform for active and adaptive IR optoelectronic devices. [ABSTRACT FROM AUTHOR]

This study aimed to establish a virtual cross cylinder method to calculate the total corneal astigmatism by combining the anterior and posterior corneal astigmatism on the secondary principal plane of the cornea based on Gaussian optics. The meridian with the least refractive power, namely, the flattest meridian of the virtual cross cylinder of a ± 0.5 × C diopter, is set as the reference meridian, and the power (F) at an angle of φ between an arbitrary meridian and the reference meridian is defined as F(φ) = − 0.5 × C × cos2φ. The magnitude and axis of the total corneal astigmatism were calculated by applying trigonometric functions and the atan2 function based on the combination of the virtual cross cylinders of the anterior corneal astigmatism and the posterior corneal astigmatism. To verify the performance of the virtual cross cylinder method, a verification experiment with two Jackson cross cylinders and a lensmeter was performed, and the measured and calculated values were compared. The limit of the natural domain of the arctangent function is circumvented by using the atan2 function. The magnitude and axis of the total corneal astigmatism are determined through generalized mathematical expressions. The verification experiment results showed good agreement between the measured and calculated values. Compared to the vector analysis method, the virtual cross cylinder method is mathematically sound and straightforward. A novel technique for calculating total corneal astigmatism, the virtual cross cylinder method, was developed and verified. [ABSTRACT FROM AUTHOR]

Color centers in wide band-gap semiconductors, which have superior quantum properties even at room temperature and atmospheric pressure, have been actively applied to quantum sensing devices. Characterizing the quantum properties of the color centers in the semiconductor materials and ensuring that these properties are uniform over a wide area are key issues for developing quantum sensing devices based on color centers. In this article, we have developed an optics design protocol optimized for evaluating the quantum properties of color centers and have used this design approach to develop a new microscopy system called columnar excitation fluorescence microscope (CEFM). The essence of this system is to maximize the amount of fluorescence detection of polarized color centers, which is achieved by large-volume and uniform laser excitation along the sample thickness with sufficient laser power density. This laser excitation technique prevents undesirable transitions to undesirable charge states and undesirable light, such as unpolarized color center fluorescence, while significantly increasing the color center fluorescence. This feature enables fast measurements with a high signal-to-noise ratio, making it possible to evaluate the spatial distribution of quantum properties across an entire mm-size sample without using a darkroom, which is difficult with typical confocal microscope systems. [ABSTRACT FROM AUTHOR]

Deep optical optimization has recently emerged as a new paradigm for designing computational imaging systems using only the output image as the objective. However, it has been limited to either simple optical systems consisting of a single element such as a diffractive optical element or metalens, or the fine-tuning of compound lenses from good initial designs. Here we present a DeepLens design method based on curriculum learning, which is able to learn optical designs of compound lenses ab initio from randomly initialized surfaces without human intervention, therefore overcoming the need for a good initial design. We demonstrate the effectiveness of our approach by fully automatically designing both classical imaging lenses and a large field-of-view extended depth-of-field computational lens in a cellphone-style form factor, with highly aspheric surfaces and a short back focal length. The authors present a design method based on curriculum learning, able to learn optical designs of compound lenses from randomly initialized surfaces without human intervention, demonstrating fully automated design of both classical imaging lenses and extended depth-of-field computational lenses. [ABSTRACT FROM AUTHOR]

Purpose: In brain development, Myelination is the characteristic feature of white matter maturation, which plays an important role in efficient information transmitting. The white matter abnormality has been reported to be associated with self-limited epilepsy with centrotemporal spikes (SeLECTS). This study aimed to detect the altered white matter region in the SeLECTS patients by the combination of diffusion tensor imaging (DTI) and quantitative susceptibility mapping (QSM) technique. Methods: 27 children with SeLECTS and 23 age- and gender-matched healthy children were enrolled. All participants were scanned with 3.0-T MRI to acquire the structure, diffusion and susceptibility-weighted data. The susceptibility and diffusion weighted data were processed to obtain quantitative susceptibility map and fraction anisotropy (FA) map. Then voxel-wise tract-based spatial statistics (TBSS) were used to analyze quantitative susceptibility and FA data. Results: Both DTI and QSM revealed extensive white matter alterations in the frontal, parietal, and temporal lobes in SeLECTS patients. The overlapped region of DTI and QSM analyses was located in the fiber tracts of the corona radiata. The FA values in this overlapped region were negatively correlated with the magnetic susceptibility values. Conclusion: Our results suggest that TBSS-based QSM can be employed as a novel approach for characterizing alterations in white matter in SeLECTS. And the combination of QSM and DTI can provide a more comprehensive evaluation of white matter integrity by utilizing different biophysical features. [ABSTRACT FROM AUTHOR]

In this study, Cu/BaTiO3/MoS2/Cu nanodevices were fabricated through magnetron sputtering at room temperature, and the adjustable resistor switching (RS) functionality of the devices under dark and illuminated conditions was systematically investigated. By designing experiments and analyzing data, we propose a conceptual model to explain the conduction mechanism of the device. Under dark conditions, the switching between high-resistance and low-resistance states can be attributed to the modulation of the interface barrier between BaTiO3 and MoS2, as well as the formation and rupture of conductive filaments between the MoS2 layers. However, under illumination, the BaTiO3 layer generates photoexcited electrons that are injected into the MoS2 layer and subsequently captured by defect states, thereby modulating the RS phenomenon. The device exhibits a high-to-low resistance ratio exceeding 104, endurance up to 103 cycles, data retention exceeding 104 s, and a dispersion voltage below 0.05 V at room temperature. The light-controlled functionality of the device provides possibilities for extending the application of resistive switching-based non-volatile random access memory to the field of optics, such as imaging sensors, optoelectronic detectors, and optoelectronic switches. [ABSTRACT FROM AUTHOR]

In this paper, the beam propagation factor (M2-factor) of the so-called vortex Hermite-cosh-Gaussian beams (vHChGB) is investigated by using the second-order intensity moments. The analytical expression of the M2-factor of the vHChGB is derived in detail, and several numerical illustrative examples are given to discuss the influence of the field structure parameters, such as the beam order n, the decentered b, and the topological charge index m, on the M2-factor. The results obtained represent a more general analysis because the considered beam has a variable shape, and it can be reduced under appropriate conditions to well-known vortex beams, such as hollow vortex-Gaussian beams, cosh vortex-Gaussian beams, and vortex Hermite beams. Our work will be useful for practical applications of vortex beams in free-space optical communications, atomic optics, and microparticle manipulation. [ABSTRACT FROM AUTHOR]

Optical sensors have seamlessly integrated the progress of materials science, giving rise to a novel class of devices. These cutting-edge sensors incorporate bioinspired sensing layers, coatings, and mechanisms, tailor-made for various specialized applications in fields like medicine, industry, and technology. This advancement paves the way for groundbreaking improvements in biosensor technology, offering enhanced capabilities for detecting and analyzing various substances in diverse settings. In this brief report the recent and future challenges in biosensors applying bioinspired sensing layers, as well as advances in science and technology to meet them, are presented. [ABSTRACT FROM AUTHOR]

This paper surveys adaptive cameras, i.e. any camera device able to change its geometric settings. We consider their classification in four categories: lensless, dioptric, catadioptric and polydioptric cameras. In each category, we report and describe all the existing adaptive cameras. Then, the known applications of these devices are summarized. Finally, we discuss open research lines for new adaptations of cameras, and their promising uses. [ABSTRACT FROM AUTHOR]

With recent technological advances, more people are moving towards the use of renewable energy instead of fossil fuels. This group includes the photovoltaic technologies that have been improving by leaps and bounds, although they still need a lot of development. Factors as the dust still need further research. In the same vein, this research work investigates the influence of sand, type of dust, and colour on the energy performance of CdTe modules. For this, experimental tests were carried out in the presence of sand and without its presence. In the tests without sand, it was found that the transparency and colour of the modules had an influence on the results, due to their connection with the spotlight irradiation spectrum. In the case of the presence of sand, with various densities, a general decrease in energy assessment parameters was observed with the exception of Fill Factor. For the computational simulation of the implemented 1M5P model, both cases were evaluated, and for the absence of sand, the errors ranged from 9.19 to 11.30%, not being very significant. With sand, the errors varied between 8.87 and 12.09%, but without any tendency with the increase of sand. It can be concluded that the model is representative and serves as an error metric for tests without sand because it was developed for this specific case. However, in the case of the tests with sand, it is no longer representative so, it would be necessary to consider in its development factors such as humidity and temperature. [ABSTRACT FROM AUTHOR]

HOBIT, which stands for "Hybrid Optical Bench for Innovative Teaching and learning" is an educational platform that leverages the combination of numerical simulation and physical manipulation to facilitate learning of complex phenomena and motivate users about wave optics in practical work. HOBIT operates in real time and is self-adaptive, providing realistic displays of optical phenomena with virtual augmentations designed to facilitate their understanding. HOBIT makes it quick and easy to build any reconfigurable optical experiment. Students can manipulate optical components and observe the changes induced on detectors and displays. We detail the technology, the simulation model and the initial teaching aids. Current and future enhancements should meet the needs of students at different levels, from high school to higher education degrees. [ABSTRACT FROM AUTHOR]

Multimodal deep learning plays a pivotal role in supporting the processing and learning of diverse data types within the realm of artificial intelligence generated content (AIGC). However, most photonic neuromorphic processors for deep learning can only handle a single data modality (either vision or audio) due to the lack of abundant parameter training in optical domain. Here, we propose and demonstrate a trainable diffractive optical neural network (TDONN) chip based on on-chip diffractive optics with massive tunable elements to address these constraints. The TDONN chip includes one input layer, five hidden layers, and one output layer, and only one forward propagation is required to obtain the inference results without frequent optical-electrical conversion. The customized stochastic gradient descent algorithm and the drop-out mechanism are developed for photonic neurons to realize in situ training and fast convergence in the optical domain. The TDONN chip achieves a potential throughput of 217.6 tera-operations per second (TOPS) with high computing density (447.7 TOPS/mm2), high system-level energy efficiency (7.28 TOPS/W), and low optical latency (30.2 ps). The TDONN chip has successfully implemented four-class classification in different modalities (vision, audio, and touch) and achieve 85.7% accuracy on multimodal test sets. Our work opens up a new avenue for multimodal deep learning with integrated photonic processors, providing a potential solution for low-power AI large models using photonic technology. Most photonic processors can only handle a single data modality due to the lack of abundant parameter training in optical domain. Here, authors propose and demonstrate a trainable diffractive optical neural network chip based on on-chip diffractive optics with tunable elements to address these constraints. [ABSTRACT FROM AUTHOR]

Next-generation light-emitting applications such as displays and optical communications require judicious control over emitted light, including intensity and angular dispersion. To date, this remains a challenge as conventional methods require cumbersome optics. Here, we report highly directional and enhanced electroluminescence from a solution-processed quasi-2-dimensional halide perovskite light-emitting diode by building a device architecture to exploit hybrid plasmonic-photonic Tamm plasmon modes. By exploiting the processing and bandgap tunability of the halide perovskite device layers, we construct the device stack to optimise both optical and charge-injection properties, leading to narrow forward electroluminescence with an angular full-width half-maximum of 36.6° compared with the conventional isotropic control device of 143.9°, and narrow electroluminescence spectral full-width half-maximum of 12.1 nm. The device design is versatile and tunable to work with emission lines covering the visible spectrum with desired directionality, thus providing a promising route to modular, inexpensive, and directional operating light-emitting devices. By exploiting Tamm plasmon modes, Ooi et al. report highly directional and enhanced electroluminescence in quasi-2D perovskite LEDs with angular FWHM of 36.6° and spectral FWHM of 12.1 nm. The photonic platform is versatile and tuneable across the visible spectral range with directionality up to 40°. [ABSTRACT FROM AUTHOR]

Anderson localization is a multiple-scattering phenomenon of linear waves propagating within a disordered medium. Discovered in the late 50s for electrons, it has since been observed experimentally with cold atoms and with classical waves (optics, microwaves, and acoustics), but whether wave localization is enhanced or weakened for nonlinear waves is a long-standing debate. Here, we show that the nonlinearity strengthens the localization of surface-gravity waves propagating in a canal with a random bottom. We also show experimentally how the localization length depends on the nonlinearity, which has never been reported previously with any type of wave. To do so, we use a full space-and-time-resolved wavefield measurement as well as numerical simulations. The effects of the disorder level and the system's finite size on localization are also reported. We also highlight the first experimental evidence of the macroscopic analog of Bloch's dispersion relation of linear hydrodynamic surface waves over periodic bathymetry. Anderson localization is a linear phenomenon, with ongoing debate about the impact of nonlinearity. This study shows that nonlinearity strengthens the localization of surface-gravity waves in a canal with a random bottom through experimental measurements and numerical simulations. [ABSTRACT FROM AUTHOR]

Humans constantly interact with their environment, with other humans, as well as natural and artificial non-human agents. Nevertheless, our somatosensory system limits the diversity of our ways of communicating. Such organisms as plants thus escape our notice, blending into the landscape. This phenomenon is called Plant blindness. This leads not only to indifference and lack of empathy towards plants among ordinary people but also to a deficit in funding plant conservation. We believe that it is important to develop connections and also rethink the relationship between humans and flora. This paper examines the Plant turn in the context of an art-science project titled Plantoverse. The scientific part of the project is based on a study of plant epidermis cells, which possess optical properties and function as a "lens". The data acquired via confocal microscopy was used to construct a mathematical model of these lenses which in turn formed the basis of the artistic work. It is a representation of the plant epidermis in a digital environment. The work allows us to look at ourselves through "plant optics'' and find new tools for interacting with the vegetal world. This interdisciplinary approach can help transfer knowledge about flora from the professional environment to lay society and form a new, more empathetic view toward plants. [ABSTRACT FROM AUTHOR]

In this manuscript, we introduce optical fractional normalization and fractional recursive operators for a particle. The significance of this research lies in obtaining optical fractional recursive operators and normalized operators of magnetic fields through the utilization of a fractional spherical frame within spherical space. Throughout the study, we employ the general form of fractional derivatives, as it enables us to derive more generalized results compared to classical derivatives. Additionally, we derive the microfluidic optical fractional electroosmotic magnetic optimistic fractional energy. We propose a design for optical recursion-based fractional electroosmotic magnetic optimistic fractional energy. This innovative study holds significant potential for applications across various fields, including fluid dynamics, optics, and energy conversion. [ABSTRACT FROM AUTHOR]

This study investigates a widely recognized Hirota–Maccari model used in plasmas, fluid mechanics, and optics. Novel dynamics of this nonlinear structure are introduced through the computational software Maple 18. Three reliable and effective methods, such as the unified scheme, the G ′ G ′ + G + A technique, and the modified rational sine–cosine approach, are applied to investigate the governing model. The stability analysis of the adopted model is also studied using the Hamiltonian approach. Our investigation yields various outcomes, such as a single dark-bright breather wave, multiple dark-bright breather waves, a local breather wave, a dark soliton, a kink wave, an anti-kink wave, a periodic wave, and an M -shaped periodic wave. Finally, the acquired outcomes are presented in two-dimensional and three-dimensional plots for various parametric values. It is shown that the mentioned techniques are reliable, effective, and applicable mathematical algorithms for solving nonlinear models. [ABSTRACT FROM AUTHOR]

In the realm of modern information technology, data compression technology occupies a pivotal position. With advancements in quantum information technology, the need to compress large-scale qubits ensembles has become urgent, aiming to reduce the demand on quantum storage resources. However, existing quantum state compression schemes generally face a limitation: the particles before and after compression must reside in the same dimensional space. In specific scenarios, compressing qubits into particles of higher dimensions not only enhances the efficiency of quantum state compression but also further reduces the usage of quantum storage resources. Here we experimentally demonstrated a quantum state compression between particles of different dimensions, successfully compressing two qubits into a single qutrit. The average fidelity of the resulting qutrit with the ideal quantum state is 0.8835. Our study may have potential applications in future quantum information, such as increasing quantum communication bandwidth and reducing storage resource consumption in quantum computing. [ABSTRACT FROM AUTHOR]

The investigation in this article focused on the role of La2O3 on the optical, physical, and radiation protection performance of La2O3-based glasses in the form 21.5SiO2-58.5B2O3-(20−x)ZnO:xLa2O3, where x , ( 0 ≤ x ≤ 10 ) mol%. The melt-quenching process was used to synthesize the glasses under study. Density results increased from 3.174 to 4.754, the values of the ( E opt. indi ) increased from 2.996 to 3.313 and ( E opt. di) increased from 3.364 to 3.689. Several radiation shielding factors have been evaluated to study the attenuation abilities of the ZBSL glasses and for all of them, there is a positive correlation between the mean free path (MFP) values and the incoming photon energy. The effective atomic number, Zeff, values increased for all the energies when La2O3 was employed in place of ZnO. Therefore, of all the competing shielding glasses and regular concrete, ZBSL10 glass is an excellent choice for shielding applications from gamma rays and neutrons. This study should be very beneficial for the design of these glasses or for the fabrication of new glasses for radiation protection. [ABSTRACT FROM AUTHOR]

Recently there has been growing interest in using photonics to perform the linear algebra operations of neuromorphic and quantum computing applications, aiming at harnessing silicon photonics' (SiPho) high-speed and energy-efficiency credentials. Accurately mapping, however, a matrix into optics remains challenging, since state-of-the-art optical architectures are sensitive to fabrication imperfections. This leads to reduced fidelity that degrades as the insertion losses of the optical matrix nodes or the matrix dimensions increase. In this work, we present the experimental deployment of a 4 × 4 coherent crossbar (Xbar) as a silicon chip and validate experimentally its theoretically predicted fidelity restoration credentials. We demonstrate the experimental implementation of 10,000 arbitrary linear transformations achieving a record-high fidelity of 99.997% ± 0.002, limited mainly by the measurement equipment. Our work represents an integrated optical circuit providing almost unity and loss-independent fidelity in the realization of arbitrary matrices, highlighting light's credentials in resolving complex computations. The Authors demonstrate a fidelity-restorable universal integrated linear optical circuit that relies on a novel 4 × 4 silicon photonic crossbar architecture. Its experimental characterization yields a fidelity of 99.93 ± 0.06%, calculated over 10,000 matrices. [ABSTRACT FROM AUTHOR]

The new extended direct algebraic technique (EDAT) is used to investigate the rational, and soliton solution for time dependent dimension-less paraxial wave model. The wave solutions help in considerations of physical phenomena and have significant applications in engineering and physics. In optics and photonics, various optical patterns of waves can be beneficial for demonstrating the dynamics behavior of optical solutions that pertain to studying a several kind of mechanical techniques involving the flow of light via optical fibers like mirror, lenses and imaging. By applying suitable parameter values, the exact solutions are obtained with dark, bright, singular, bright-dark, periodic form by using Mathematica 11.0. The 3-D density, 2-D plot and contour plot are plotted and explored the self-focusing structure of electromagnetic waves in non-linear techniques to present a physical description of examined solutions using Matlab. The obtain soliton solutions demonstrate the non-dispersive and non-diffractive localized propagation wave packets in optical kerr media. [ABSTRACT FROM AUTHOR]

Biocompatible optical devices are breakthrough illumination, imaging, and biomedical sensing technologies. Despite the noteworthy developments in silk, cellulose, and hydrogel-based optics, such approaches rely on expensive precursors and intricate fabrication. Therefore, agar extracted from red algae emerges as a promising biodegradable alternative as an edible, low-cost, and renewable material. This paper overviews the state-of-the-art of agar-based optical devices. Firstly, we revisit this phycocolloid's fundamentals and highlight its appealing mechanical, optical, and electrical characteristics. Subsequently, we summarize the available agar elements, slab waveguides, and optical fibers. Lastly, we discuss their advantages and challenges by envisaging opportunities for future developments and applications. [ABSTRACT FROM AUTHOR]

We describe a method for estimating detection depth of underwater hydrodynamic structures in above-water optical data. In situ and remote sensing data, as well as numerical modeling of the formation of upward radiation from the water surface are used for the design. The results of this study improve the interpretation of spectral data obtained from remote sensing of water color, which is associated with vertical variations in the content of optically active substances. Additionally, the method allows for determining the thickness of the surface layer within which some hydrodynamic phenomena can be remotely detected in the visible spectral range. [ABSTRACT FROM AUTHOR]

Microscopes are indispensable devices of laboratories. They are widely used in industry and science, such as medicine, geology, biology, chemistry and so on. Thanks to the developing technology, manual microscopes are leaving their place to automatic systems. However, automatic microscopy systems are difficult to obtain due to their high costs. The best way to circumvent this problem is to reduce device costs as much as possible. Based on this idea, a fully automated digital microscope system (FADMS) has been proposed as a low-cost prototype. The FADMS can scan and autofocus for various microscopic samples. In addition, it can be controlled over the internet thanks to a developed software and can store scanned microscopic images. The total cost of the developed system is around 2500 US dollars. In experimental studies, mechanical motion sensitivity and focusing tests of the FADMS were performed. Five different methods were tested on peripheral blood smear images for autofocus. According to the results obtained based on six different measurement criteria, Brenner's and Geusebroek's method showed the best performance. In positioning tests for the mechanical stage (X and Y axes), the motors in the driving system were moved forward and backward for a distance of 100 μm. The results obtained showed a deviation of 2.6 μm for the X-axis and 3.6 μm for the Y-axis. Experimental results show that micron-sized biological cells can be observed in detail. The FADMS has been designed in a modular structure that allows it to be replaced with lighting, optical system and imaging device alternatives. In terms of performance/cost ratio, the FADMS is attractive for high-throughput microscopy applications ranging from digital pathology to health screening in low-income countries and is considered to be an alternative solution for many industries. [ABSTRACT FROM AUTHOR]

In the course of the Horizon 2020 project HighNESS, a second moderator concept has been developed for the European Spallation Source, which complements the currently built moderator and is optimized for high intensity with a large viewable surface area. In this work we introduce conceptual designs for neutron instruments for condensed matter research designed to make optimal use of the capabilities of this moderator. The focus is on two concepts for small-angle neutron scattering and one neutron imaging instrument, which are intended to complement corresponding instruments that are already under construction at the European Spallation Source. One small-angle neutron scattering instrument concept resembles a conventional pinhole collimator geometry and aims to profit from the proposed second moderator by enabling to illuminate larger samples and providing particularly high resolution, drawing on a 30 m collimation and corresponding detector distance. A second small-angle neutron scattering instrument concept adopts nested mirror optics that enable to efficiently exploit the large moderator size and provide high resolution by focusing on the detector. The neutron imaging instrument concept is a typical pinhole instrument that can be found at continuous sources and draws on the corresponding strengths of high flux and large homogeneous fields-of-view, while still providing moderate wavelength resolution for advanced imaging methods. [ABSTRACT FROM AUTHOR]

Extreme ultraviolet (EUV) light is difficult to focus due to strong absorption of most materials. Photon sieves (PS), rather than Fresnel zone plates (FZP), can focus EUV to smaller spot and suppress the higher orders of secondary maxima by several orders of magnitude. The number of pinholes used in PS is far more than that of transparent rings used in FZP, providing a great flexibility to manipulate structured focusing in EUV. In this work we investigate the Fermat-spiral PS to produce focused vortices with different topological charges. Experiment at the wavelength of 46.9 nm is carried out and multi-planar coherent diffractive imaging is used to retrieve the phase map of the focused EUV vortices. These results show the enormous potential of PS for manipulating EUV light. This study not only provides a compact, affordable substitute to focusing vortices where transmissive optics materials are unavailable, but also provides a route of converting various complex light manipulation ranging from visible light to EUV and soft x-ray. [ABSTRACT FROM AUTHOR]

The dangerous chemical elements associated with nanoparticles (NPs) and ultra-fine sediment particles in hydrological bays have the capacity to move contaminants to large oceanic regions. The general objective of this study is to quantify the major chemical elements present in NPs and ultra-fine particles in aquatic sediments sampled from Guanabara Bay and compare these data to values determined through spectral optics using the Sentinel-3B Satellite OLCI (Ocean Land Color Instrument) during the winter and summer seasons of 2018, 2019, 2020, 2021, and 2022. This is done to highlight the impacts anthropogenic environmental hazards have on the marine ecosystem and human beings. Ten aquatic sediment field collection points were selected by triangulated irregular network (TIN). Samples were subjected to analysis by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron dispersion spectroscopy (EDS), and transmission electron microscopy (TEM), which enabled a detailed analysis using scanning transmission electron microscopy (STEM). Geospatial analyses using Sentinel-3B OLCI Satellite images considered Water Full Resolution (WFR) at 300 m resolution, in neural network (NN), normalized at 0.83 µg/mg. A maximum average spectral error of 6.62% was utilized for the identification of the levels of Absorption Coefficient of Detritus and Gelbstoff (ADG443_NN) at 443 m−1, Chlorophyll-a (CHL_NN) (m−3), and Total Suspended Matter (TSM_NN) (g m−3) at 581 sample points. The results showed high levels of ADG443_NN, with average values as high as of 4444 m−1 (summer 2021). When related to the analyses of nanoparticulate sediments and ultrafine particles collected in the field, they showed the presence of major chemical elements such as Ge, As, Cr, and others, highly toxic to human health and the aquatic environment. The application of satellite and terrestrial surveys proved to be efficient, in addition to the possibility of this study being applied to other hydrological systems on a global scale. [ABSTRACT FROM AUTHOR]

Promising wavelengths for next-generation lithography with a wavelength shorter than 13.5 nm based on a synchrotron X-ray source are discussed. Theoretical and experimental values of the reflection coefficients of multilayer X-ray mirrors providing the maximum reflectivity in the range of 11.4–3.1 nm are presented. The theoretical efficiency of multilayer optics is compared for different wavelengths. [ABSTRACT FROM AUTHOR]

In this paper, the security of linear optics cloning machine-enhanced passive state preparation continuous-variable quantum key distribution is investigated. The employment of passive state preparation eliminates the strict requirements on electro-optical modulators, while an appropriately tuned linear optics cloning machine can compensate the preparation noise introduced in passive state preparation and improve the system performance. The expression of the composable secret key rate in the finite-size regime of the proposed scheme is obtained. Simulation results demonstrate that the proposed scheme can effectively enhance the secret key rate and increase the maximum secure transmission distance. [ABSTRACT FROM AUTHOR]

Entanglement concentration protocol (ECP), as a practical technique, can be use to preclude degraded fidelity and improve security in long-haul quantum communication. We propose an efficient ECP for less-entangled unknown W states with simple linear-optics elements and effective single-photon detectors, resorting to time-delay degree of freedom. Moreover, in contrast to previous ECPs proposed for W states, the scheme has the advantages over requiring less quantum resource without auxiliary photons, comparatively simplified circuits, involving neither post-selection techniques nor photon-number-resolving detectors to distinguish the parity outcome, and being provided with a higher success probability by reusing the less-entangled states. [ABSTRACT FROM AUTHOR]

Band engineering stands as an efficient route to induce strongly correlated quantum many-body phenomena. Besides inspiring analogies among diverse physical fields, tuning on demand the group velocity is highly attractive in photonics because it allows unconventional flows of light. Λ-schemes offer a route to control the propagation of light in a lattice-free configurations, enabling exotic phases such as slow-light and allowing for highly optical non-linear systems. Here, we realize room-temperature intercavity Frenkel polaritons excited across two strongly coupled cavities. We demonstrate the formation of a tuneable heavy-polariton, akin to slow light, appearing in the absence of a periodic in-plane potential. Our photonic architecture based on a simple three-level scheme enables the unique spatial segregation of photons and excitons in different cavities and maintains a balanced degree of mixing between them. This unveils a dynamical competition between many-body scattering processes and the underlying polariton nature which leads to an increased fluorescence lifetime. The intercavity polariton features are further revealed under appropriate resonant pumping, where we observe suppression of the polariton fluorescence intensity. Band engineering in optics allows the design of unconventional forms of light with potential optoelectronic applications. Here, the authors realize slow-light intercavity polaritons in an array of coupled cavities, the photonic architecture enables the spatial segregation of photons and excitons [ABSTRACT FROM AUTHOR]

Optical beam propagation through the atmosphere is suffering from turbulence condition and scattering due to the refractive index effects on propagation. In this paper, we study optical beam propagation under the UAE's weather conditions. An outdoor test was carried out to gather the atmosphere parameters (temperature, wind, humidity, and refractive index) and feed them to a beam propagation model. The beam centroid was determined to study and predict the effects on it at different periods of the day. [ABSTRACT FROM AUTHOR]

Biocompatible polymers such as poly(vinyl pyrrolidone) (PVP) are used to prepare hydrogels for biomedical applications, optical applications, cosmetic and smart medical contact lenses, and many other applications. However, the commercial PVP lenses available today are optically poor, and wearers of PVP medical contact lenses typically experience spherical, coma, astigmatism, and chromatic aberrations due to light dispersion when the pupil is opened at 2.50 mm. In this work, three contact lenses were prepared by doping PVP hydrogel with 0.1%, 0.5%, and 1% by weight of laboratory-manufactured silver nanoparticles (Ag NPs). This work demonstrates the evaluation of vision correction through each lens and the effect of changing the concentration of Ag NPs on its refractive index. The simulation included the design and simulation of an aberrated human eye based on the Liou and Brennan model and the insertion of the contact lenses for vision correction using the ZEMAX optical design program. The resulting refractive index of one PVP-Ag lens was relatively high at 532 nm = 1.545, leading the lens to guide light rays into a small spot of 3.983 µm root mean square and a highest image contrast (lowest MTF curve degradation) of 0.863 ± 0.027 at 20 cycles/mm. [ABSTRACT FROM AUTHOR]

In this work, an analytical model to study graphene-based spatiotemporal modulated structures is developed and verified through comparison with full wave numerical simulations. Graphene is an ideal material for realizing spatiotemporal modulated structures at high frequencies of THz and optics. In this analysis, the electromagnetic response of studied structures is expressed in terms of weighted Floquet-Bloch modes supported by the structure, while graphene is modeled by a spatiotemporal modulated surface current that imposes certain boundary conditions on the modes. The developed analytical technique is a comprehensive tool and can be used for accurate modeling of different kinds of spatiotemporal devices including lossy, guided, and leaky wave structures. To demonstrate the accuracy of the model, two plasmonic waveguides with space and time modulated graphene conductivity are analyzed and their interband and intraband transition between modes are thoroughly investigated. Using the developed analytical model, spatiotemporal modulation phenomena such as mode conversion, wave amplification and nonreciprocal response are explored and discussed for the studied structures. [ABSTRACT FROM AUTHOR]

The in vivo diagnosis and monitoring of pulmonary disorders (caused for example by emphysema, Covid-19, immature lung tissue in infants) could be effectively supported by the non-invasive sensing of the lung through light. With this purpose, we investigated the feasibility of probing the lung by means of time-resolved diffuse optics, leveraging the increased depth (a few centimeters) attained by photons collected after prolonged propagation time (a few nanoseconds). We present an initial study that includes measurements performed on 5 healthy volunteers during a breathing protocol, using a time-resolved broadband diffuse optical spectroscopy system. Those measurements were carried out across the spectral range of 600–1100 nm at a source-detector distance of 3 cm, and at 820 nm over a longer distance (7–9 cm). The preliminary analysis of the in vivo data with a simplified homogeneous model revealed a maximum probing depth of 2.6–3.9 cm, suitable for reaching the lung. Furthermore, we observed variations in signal associated with respiration, particularly evident at long photon propagation times. However, challenges stemming from both intra- and inter-subject variability, along with inconsistencies potentially arising from conflicting scattering and absorption effects on the collected signal, hindered a clear interpretation. Aspects that require further investigation for a more comprehensive understanding are outlined. [ABSTRACT FROM AUTHOR]

Vectorial optics with fine inhomogeneous polarization control are highly desired. Metasurfaces have been captivated a promising candidate, but their static post-fabrication geometry largely limits the dynamic tunability. Liquid crystal (LC) is usually employed as an additional index-changing layer together with metasurfaces. Unfortunately, most of the reported LCs only impart a varying but uniform phase on top of that from the metasurface, which we term "scalar" LC optics. Here, we pixelate a single-layer LC to display versatile and tunable vectorial holography, in which the polarization and amplitude could be arbitrarily and independently controlled at varying spatial positions. Furthermore, the subtle and vectorial LC-holography highlights the broadband and electrically-switchable functionalities. Our vectorial LC holography reveals significant opportunities for advanced cryptography, super-resolution imaging, and many other applications. [ABSTRACT FROM AUTHOR]

Focusing on the problem of unclear ray-traced spots and their distribution rules in the design process of the Herriott cell, first, the characteristics of long-optical-path gas absorption cells were analyzed, and the calculation method of basic cavity length and the effective optical path of Herriott gas absorber cells were studied. Second, according to the transmission characteristics of geometric optics, a physical model of light transmission in Herriott cells was established via the LightTools software. Finally, simulation analysis was performed on Herriott cells with 5- and 14.4-m optical paths separately, determining the quantitative relationship between d/f and the number of spots reflected on the concave mirror, and optimizing the effective optical path and output laser energy of the Herriott cells. Through research analysis, the sizes and distribution positions of concave mirror spots in the Herriott cells were identified, as well as the factors affecting the number of reflections. It was also found that the number of reflected spots gradually decreases as d/f increases, revealing the light-tracing results and its spot distribution rule on the mirror surface, as well as verifying the accuracy of the theory. The findings of this study provide a basis for the optical path system design and optimization for Herriott cells with different optical path lengths. [ABSTRACT FROM AUTHOR]

Expressions are obtained for the position of the maximum Imax of the Fourier transform of a Bessel–Gaussian beam (BGB) and its dependence on the topological charge is substantiated. It is found that Imax depends on the angle of the cone and the parameters of the Gaussian beam. Here, as the cone angle is reduced (and, therefore, the diffraction-free region increases), the distances between the maxima of the intensity distributions in the focal plane of the lens, corresponding to different magnitudes of the topological charge, increase. An expression is found for the position of the energy center of the Fourier transform of the BGB and it is shown that it also depends on the cone angle γ and the size of the Gaussian beam waist w0. As the product γw0 increases, the shift in the energy center of the BGB relative to the radius R of the annular Fourier spectrum in the approximation of geometric optics decreases. These results reveal the impossibility of forming perfect vortices with a BGB. Here the degree of their "imperfection" is determined by the deviation of the maximum of the intensity distribution in the focal plane of the lens on the parameter R which specifies the radius of the ring of the Fourier image of the Bessel beam, which is greater for beams with a larger diffraction-free region. [ABSTRACT FROM AUTHOR]

An overview of publications dedicated to the application of various X-ray fluorescence techniques for investigating the chemical composition of ancient ceramics and clays is presented. Examples of conventional wavelength dispersive and energy dispersive X-ray fluorescence spectrometers, portable X-ray analyzers, spectrometers with polycapillary optics (micro X-ray fluorescence spectrometry), and total reflection geometry are considered. Although X-ray fluorescence serves as the analytical signal in all cases, the listed X‑ray fluorescence techniques differ in the range of analytes, methods of sample preparation, and methods for calculating element concentrations. The author experience in applying the described techniques of X-ray fluorescence spectrometry to a comprehensive study of archaeological materials from the Stone Age for the historical reconstruction of economic activities in the Baikal Siberia population is also discussed. [ABSTRACT FROM AUTHOR]

Propagation of light through a random scattering media is a challenging, yet a highly practical problem in numerous fields, such as in astronomy, medical diagnosis, non-line-of-sight imaging, imaging through fog, etc. Scattering media distort the light and generate a random pattern without any directly useful information. Nevertheless, the randomness of the light plays a significant role in designing and developing correlation-based imaging and measurement techniques. Correlation optics exploits the intrinsic fundamental features of randomness to unveil hidden information within the scattered light. This mini-review highlights the role of polarization correlation and pilot-assisted beam guiding through scattering medium in information recovery through random scattering media. Here, one of the orthogonal polarization components of the light is loaded with the information and the other is without the information, and this special scheme of the colinear beam propagation through the random scattering medium is referred to as the pilot-assisted beam guiding. Such a pilot-assisted propagation strategy helps to counter the randomness and preserves the desired information through the scattering channel. In this article, we mainly focus on the recent progress and advancement in polarization correlation with pilot-assisted beam guiding in looking through random scattering media. [ABSTRACT FROM AUTHOR]

A fateful decision as a 15-year-old high school student, and good advice from a distinguished professor of zoology, were the catalysts that not only decided my entire career but also led me to the Journal of Comparative Physiology A, and to the myriad biological wonders that were held within its covers. In my celebration of JCPA, I look back on the formative years of my career in Australia, and the crucial role that the journal played in shaping my emerging research interests, and ultimately my entire life. [ABSTRACT FROM AUTHOR]

Optical systems, such as a mobile LiDAR system, encounter mechanical disturbances associated with the condition of the road, resulting in significant misalignments in the optical paths within the system. To address this issue, considerable time is dedicated to the realignment process to restart the system. A suggested approach to overcome this challenge involves the implementation of automatic realignment through the control of the motion of the steering mirrors using an advanced control technique known as Model Predictive Control (MPC). This technique, which is relatively new in the field of optics, is widely utilized in the industry due to its capability to manage and resolve a broad range of problems that are inherent to industrial systems, particularly, those that are subject to constraints or undergo disturbances during operation. In this study, we utilize MPC on the optical chain, specifically the LiDAR component, to regulate the beam and promptly rectify any flexure that occurs during both constant and variable trajectories, as well as in the presence of disturbances. A comparative analysis is conducted with the PID controller to evaluate the performance of the advanced technique proposed. [ABSTRACT FROM AUTHOR]

Diverse aspects of real-world problems are portrayed through nonlinear Schrodinger equations. This exploration considers a pair of fractional order Schrodinger equations describing important nonlinear instability phenomena which are related to heat pulse, quantum condensates, nonlinear acoustics, hydrodynamics, and nonlinear optics. The improved auxiliary equation and improved tanh schemes are imposed on the governing model which generate a bulk of innovative accurate wave solutions. Plenty of wave solutions achieved in this study could be utilized to characterize the interior mechanisms of intricate phenomena relating to the considered nonlinear models. Some of the solutions are selected to figure out in the sense of contours, 3D and 2D outlines after assigning suitable values to the involved free parameters. The directed techniques are employed to explore appropriate wave solutions of the above-stated nonlinear model for the first time ensuring the unique solutions rather than the results in earlier studies. This present work highlights the competency of used methods celebrating huge appropriate wave solutions of suggested complex nonlinear models and gives a guideline for related future research. [ABSTRACT FROM AUTHOR]

The current research aims to create of novel nanostructured films from silicon sarbide(SiC)/cerium oxide (CeO2) doped polyvinyl alcohol (PVA) as a promising nanocomposites materials to utilize in numerous quantum electronics and optical nanodevices. The fabricated nanostructures have great properties compared of other nanomaterials comprised few cost, excellent optical characteristics, flexible and lightweight. The structure, optical, and electronic features of PVA/SiC/CeO2 nanostructures were investigated. The structure properties included optimization, FTIR and optical microscope (OM). The optical characteristics were tested at wavelength ranged (200–800) nm. The optical characteristics results indicated that the absorbance of PVA rises about 76.9% at (λ = 240 nm, UV-spectra) while rises of 87% at (λ = 540 nm, VIS-spectra) when the SiC/CeO2 NPs content reached of (5.7 wt%).%. The energy gap decreased when the SiC/CeO2NPs content reached of 5.7wt% where it reduced from 4.5 to 2.7 eV, this performance make them appropriate for may optoelectronics nanodevices like transistors, photovoltaic cell, electronic gates, lasers, diodes and other applications. The optical parameters of PVA; with an increase in the SiC/CeO2 NPs content, the optical conductivity(σop), real (ε1) and imaginary (ε2) dielectric constants, absorption coefficient (α), refractive index (n), extinction coefficient (k), and other properties improved. Finally, the obtained results demonstrated that the PVA/SiC/CeO2 nanostructures are promising nanomaterials to employ in many quantum electronics and optical nanodevices. [ABSTRACT FROM AUTHOR]

We present here research seeking to develop an automated method for determining blood groups. Agglutination reactions are detected by photometry of the test sample, which consists of a sessile drop, along with application of mechanical influences to the samples. The influences of the nature of mechanical vibrations on the distribution of immune complexes in the study samples were demonstrated experimentally. A mechanical vibration mode was selected and experimentally grounded for detection of immunological reactions in samples containing monoclonal antibodies and human blood. This method can provide the basis for creating a device for blood group determination and for identifying donor/recipient compatibility during surgical interventions. [ABSTRACT FROM AUTHOR]

The current work presents a detailed numerical analysis in a solar parabolic trough collector with optimized secondary optics to enhance the thermal performance of the PTC. The heat flux distribution on an absorber tube of a standard LS-3 collector system was evaluated under different slope error conditions. The obtained heat flux distribution is adopted in the present study for thermal analysis. The simulation is carried out using the ANSYS FLUENT 15.0 tool with standard k–ε viscous model and Therminol VP-1 as the heat transfer fluid. The influence of slope error on the thermal performance of the standard and proposed model has been illustrated and investigated in detail. The thermal performance parameters are evaluated for the Reynolds number ranging from 5000 to 50,000 and with three different inlet temperatures of 400, 500 and 600 K. The proposed model has been compared in terms of Nusselt number and friction factor with the standard LS-3 collector. The outcome confirms that the proposed model performs well than standard one. The incorporation of optimized secondary optics exhibited a maximum available and overall thermal efficiency of 92.6 and 84.2%, respectively. The maximum heat transfer coefficient and exergy efficiency of 1481 W/m2K and 52.8%, respectively, was obtained. [ABSTRACT FROM AUTHOR]

The optimization of separator masses in this paper is based on the realization of the linearity of the system under study and the consequences of Liouville's theorem. The properties of several mass separators with an ion energy of 30 keV and a beam emittance of 4 mm mrad are considered. Focusing is provided by an aberration-free lens and a magnetic corrector. Phase diagrams along the beam path are in the form of parallelograms, which indicates the absence of geometric aberrations. For each of the separators, the resolution calculated in the linear approximation coincides with the simulation results. It is shown that a mass separator based on a magnet with a rotation angle of 54.7° has a resolution of about 5000, and a separator based on two magnets with a rotation angle of 45° and 90°, respectively, has a resolution of 14 000–15 000. [ABSTRACT FROM AUTHOR]

We are researching a new display device that allows the public to experience augmented reality without wearable devices. In this paper, we implement an image processing system that improves the dynamically changing image quality deterioration, which is a problem unique to optical systems that project images on the real space, and specify the necessary system requirements from the results of verification of the effect. We quantify the characteristics of blur for each of the three primary colors defined as digital image data, and implement image processing that applies filter correction to the input image data during aerial imaging. Since the effect on image quality depends on what kind of imaging optical path is formed, we designed the device structure assuming that it will be applied to signage products, and built an experimental environment that can analyze the aerial image that the user actually sees. The image subjected to the correction process follows an optical path that forms an image in the air, and the user visually recognizes the image with emphasized edges. We compared the results of the actual aerial image and the simulation results, and clarified the system requirements for realizing an image processing system with higher correction accuracy. [ABSTRACT FROM AUTHOR]