Interaction Of Light Research Articles

Singlet Oxygen in Photodynamic Therapy.

Photodynamic therapy (PDT) is a therapeutic modality that depends on the interaction of light, photosensitizers, and oxygen. The photon absorption and energy transfer process can lead to the Type II photochemical reaction of the photosensitizer and the production of singlet oxygen (1O2), which strongly oxidizes and reacts with biomolecules, ultimately causing oxidative damage to the target cells. Therefore, 1O2 is regarded as the key photocytotoxic species accountable for the initial photodynamic reactions for Type II photosensitizers. This article will provide a comprehensive review of 1O2 properties, 1O2 production, and 1O2 detection in the PDT process. The available 1O2 data of regulatory-approved photosensitizing drugs will also be discussed.

Effect of various processing parameters on the properties of ZnO thin films

Zinc oxide (ZnO) thin films are essential in opto-/piezo-electronics due to their transparency, high electron mobility, wide bandgap (∼3.37 eV), and high excitonic binding energy (60 meV). Effects of processing parameters on ZnO thin films, such as the molarity, ageing, thickness, and calcination temperature, on the microstructural and optical properties deposited by sol-gel spin-coating are investigated under one roof. X-ray diffraction (XRD) confirmed the polycrystalline nature of all films, along with a dominant orientation (002) plane, indicating the formation of a c-axis oriented hexagonal wurtzite structure of ZnO regardless of the processing parameters. Peak intensities varied for all samples and exhibited the highest peak intensity annealed at 500 °C, which correlates with the increase in crystallite size from 15.93 to 16.41 nm due to a decrease in defect density via the thermal expansion. 0.4 M aged solution over 70 h showed the variation in the crystallite size and dislocation density, indicating the improvements in the thin film quality. Thickness-dependent ZnO thin films also improved the crystallinity, which was confirmed by high peak intensities. Decreasing the Urbach energy (Eu) of 0.4 M solution indicates reduced lattice imperfections/defects and high electronic quality of thin-film materials. Deposited ZnO films with an ageing time of 70 h and thickness of 109 nm exhibit the highest refractive index of 3.9 and 2.6, indicating light interaction and optimal density. The optimized conditions of sol-gel derived ZnO thin films augment the ease of development of economic devices for practical implications in opto-/piezo-electronics.

Flame aerosol deposition Y3Al5O12:Yb 3+ , Er 3+ nanoparticles on monolayer MoS2 for broadening near-infrared photoelectroresponse

Monolayer molybdenum disulfide (MoS2) is a two-dimensional material with a direct bandgap widely used in photoelectric detection. It exhibits excellent characteristics such as an ultra- high specific surface area, strong light interaction, and good carrier mobility. However, due to the bandgap limitation, monolayer MoS2 can only efficiently detect visible wavelengths less than 680 Combining lanthanide-doped upconversion nanoparticles with monolayer MoS2 to realize near- infrared (NIR) photodetection is a feasible strategy. Thus, Y3Al5O12:Yb 3+ , Er3+ up-conversion nanoparticles are deposited on the surface of a monolayer MoS2 by flame aerosol deposition (FAD), significantly extending their photoelectric response range to the near-infrared 980 nm. The Y3Al5O12:Yb 3+ , Er3+ nanoparticles synthesized by flame can achieve efficient up-conversion from near-infrared (~980 nm) to visible light (~450, ~550, ~650 nm). Therefore, the visible light can be subsequently absorbed by monolayer MoS2. The carefully designed Y3Al5O12:Yb 3+ , Er3+ /MoS2 photodetector shows strong responsivity and highly specific detectivity in the near-infrared spectrum. Under the bias voltage of 3 V and laser irradiation of 980 nm at 2.8 μW, the newly designed MoS2 device achieves a responsivity of 16.82 A/W and a specific detectivity of 1.47×10 12 Jones, as the traditional monolayer MoS2 usually responds to zero. This work can further expand the application of two-dimensional materials and their composites in near-infrared photoelectric detection

Porous cellulose photonic film via controlled unidirectional interlayer freezing for rapid visual sensing

Structure color, arising from the interaction of light with regularly arranged sub-micrometer-sized structures, has spurred interest in sensor design. However, typical cellulose nanocrystal (CNC) photonic films derived from biomass, known for their sustainability and cost-effectiveness, often suffer from limited sensitivity and slow response times due to their dense structure. To address this challenge, we have utilized a unidirectional interlayer freezing-photopolymerization strategy to introduce porous structures into CNC photonic films without compromising their vibrant structural color. This method harnesses ice crystal-induced lamellar pores while preserving the periodic arrangement of CNCs. The underlying mechanism of ice kinetics and CNC assembly is established, highlighting the transition from non-iridescent aerogels to iridescent, porous photonic films. The resulting porous CNC photonic film exhibits apparent color response and rapid sensing capabilities in response to various solvent stimuli, outperforming its non-porous counterparts. We have validated the film as a portable vapor detector for rapid visualized alcohol detection. This approach provides promising developments in sustainable, highly responsive sensor technologies.

Blind non-linear spectral unmixing with spatial coherence for hyper and multispectral images

Multi and hyperspectral images have become invaluable sources of information, revolutionizing various fields such as remote sensing, environmental monitoring, agriculture and medicine. In this expansive domain, the multi-linear mixing model (MMM) is a versatile tool to analyze spatial and spectral domains by effectively bridging the gap between linear and non-linear interactions of light and matter. This paper introduces an upgraded methodology that integrates the versatility of MMM in non-linear spectral unmixing, while leveraging spatial coherence (SC) enhancement through total variation theory to mitigate noise effects in the abundance maps. Referred to as non-linear extended blind end-member and abundance extraction with SC (NEBEAE-SC), the proposed methodology relies on constrained quadratic optimization, cyclic coordinate descent algorithm, and the split Bregman formulation. The validation of NEBEAE-SC involved rigorous testing on various hyperspectral datasets, including a synthetic image, remote sensing scenarios, and two biomedical applications. Specifically, our biomedical applications are focused on classification tasks, the first addressing hyperspectral images of in-vivo brain tissue, and the second involving multispectral images of ex-vivo human placenta. Our results demonstrate an improvement in the abundance estimation by NEBEAE-SC compared to similar algorithms in the state-of-the-art by offering a robust tool for non-linear spectral unmixing in diverse application domains.

Three-dimensional object reconstruction based on spin–orbit interaction of light

Three-dimensional (3D) reconstruction has received extensive attention in recent years and is of great significance to various application fields. We propose a simple method of 3D object reconstruction based on spin–orbit interactions occurring from light reflection at the air–glass interface. By rotating the object, edge images of the object in various orientations are obtained; we overlap these edge images to ultimately reconstruct the 3D object. This 3D image detection based on spin–orbit interaction of light provides a low energy consumption, low cost, and more algorithmic method compared to traditional 3D image processing. This can be used in fields such as medicine, autonomous vehicles, planetary observation, and other areas.

Advancing SARS‐CoV‐2 Variant Detection with High Affinity Monoclonal Antibodies and Plasmonic Nanostructure

AbstractA nanoplasmonic biosensor for the precise detection of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) by leveraging advances in nanostructured sensing materials and highly selective monoclonal antibodies is presented. The sensor integrates plasmonic Au nanostructures optimized for surface‐enhanced Raman scattering (SERS), enhancing sensitivity through unique light interactions at the nanoscale. Coupled with exclusive antibodies that specifically target SARS‐CoV‐2 and its evolving variants, this sensor demonstrates remarkable selectivity and versatility. Validated with 270 clinical samples, it demonstrates a sensitivity of 98.9% and specificity of 100%. More importantly, the virus in nasopharyngeal swab samples collected over 3 years, marking the long‐term, large‐scale clinical validation of the nanoplasmonic biosensor for SARS‐CoV‐2 is been successfully detected. Furthermore, the integration of this sensor with face masks enables the detection of airborne SARS‐CoV‐2, highlighting its potential for routine management of coronavirus disease 2019 (COVID‐19).

Experimental investigation of the impact of model complexity on indoor daylight spectral simulations

Daylight spectral simulation is crucial for designing functional, healthy spaces and predicting light interactions. It is essential for accurate non-image-forming effects of light calculations. This study addresses the knowledge gap in reproducing indoor daylight spectral conditions in the built environment. Using varying levels of geometry (LOG) and information (LOI), simulation accuracy was assessed by comparing it with experimental data from two offices over three days with cloudy and clear sky conditions. The lowest accuracy was found with high LOI and low LOG simulations. For the highest accuracy, specific material spectral properties are needed, while spectrally-neutral materials at low LOG produced comparable results. Simulations near and facing windows were the most accurate. The study concludes that to reproduce indoor daylight spectral conditions, modelling should use either the lowest or highest geometry and information complexity, depending on available modelling time and required accuracy.

Theory and Measurement of Heat Transport in Solids: How Rigidity and Spectral Properties Govern Behavior.

Models of heat transport in solids, being based on idealized elastic collisions of gas molecules, are flawed because heat and mass diffuse independently in solids but together in gas. To better understand heat transfer, an analytical, theoretical approach is combined with data from laser flash analysis, which is the most accurate method available. Dimensional analysis of Fourier's heat equation shows that thermal diffusivity (D) depends on length-scale, which has been confirmed experimentally for metallic, semiconducting, and electrically insulating solids. A radiative diffusion model reproduces measured thermal conductivity (K = DρcP = D × density × specific heat) for thick solids from ~0 to >1200 K using idealized spectra represented by 2-4 parameters. Heat diffusion at laboratory temperatures (conduction) proceeds by absorption and re-emission of infrared light, which explains why heat flows into, through, and out of a material. Because heat added to matter performs work, thermal expansivity is proportional to ρcP/Young's modulus (i.e., rigidity or strength), which is confirmed experimentally over wide temperature ranges. Greater uptake of applied heat (e.g., cP generally increasing with T or at certain phase transitions) reduces the amount of heat that can flow through the solid, but because K = DρcP, the rate (D) must decrease to compensate. Laser flash analysis data confirm this proposal. Transport properties thus depend on heat uptake, which is controlled by the interaction of light with the material under the conditions of interest. This new finding supports a radiative diffusion mechanism for heat transport and explains behavior from ~0 K to above melting.

On-demand green/red light-responsive self-doped SnO2 nanoparticles for single/multi-color transitioning fabrics

Semiconductor/redox-based dual light-induced color switching systems (LCSs) with a visible light response at different wavelengths are highly sought after for efficient redox reactions. In this work, Sn2+ self-doped SnO2 has been designed as nanophotocatalysts for preparing visible light-responsive inks/fabrics with single/multi-color abilities. The self-doping of SnO2 nanoparticles results in the formation of oxygen vacancies due to charge compensation effects leading to electron-driven photoreduction and photooxidation of LSC inks. By mixing SnO2-x nanoparticles dispersions with specific redox-sensitive dyes can lead to the creation of well-designed sets of visible light-responsive semiconductor-driven LCS systems with both single-color (RGB) and multi-color (violet and green) changes. The exposure of LCS inks to green (550 nm) light culminates in the rapid photoreduction of the inks to decolorized state, while red (660 nm) light initiates the photooxidation in air. The combination of the LCS inks with –OH-rich polymers can be coated on the hydrophobic surface of the layered fabric to produce photo-responsive fabrics with single/multi-color response. The interaction of green light with the semiconductor-driven LCS systems allows the remote photo-printing of different images/letters on the LCS fabrics. Spontaneous erasure can be achieved by red light with high stability and repeatability (>35 cycles). The research in this paper provides new perspectives and insights for the development of new color-changing materials with potential applications as light-activated sensors and display units.

Transverse Spin-Orbit Interaction of Light.

Light carries both longitudinal and transverse spin angular momentum. The spin can couple with its orbital counterpart, known as the spin-orbit interaction (SOI) of light. Complementary to the longitudinal SOI known previously, here we show that transverse SOI of light is inherent in the Helmholtz equation when transverse spinning light propagates in curved paths. It lifts the degeneracy of dispersion relations of light for opposite transverse spin states, analogous to the Dresselhaus effect. Transverse SOI is ubiquitous in nanophotonic systems where transverse spin and optical path bending are inevitable. It can explain anomalous effects like the dispersion relation of surface plasmon polaritons on curved paths and the energy level of whispering gallery modes. Our results reveal the analogies of spin photonics and spintronics and offer a new degree of freedom for integrated photonics, spin photonics, and astrophysics.

Organic Crystals and Optical Functions in Biology: Knowns and Unknowns.

Organic crystals are widely used by animals to manipulate light for producing structural colors and for improving vision. To date only seven crystal types are known to be used, and among them β-guanine crystals are by far the most widespread. The fact that almost all these crystals have unusually high refractive indices (RIs) is consistent with their light manipulation function. Here, the physical, structural, and optical principles of how light interacts with the polarizable free-electron-rich environment of these quasiaromatic molecules are addressed. How the organization of these molecules into crystalline arrays introduces optical anisotropy and finally how organisms control crystal morphology and superstructural organization to optimize functions in light reflection and scattering are also discussed. Many open questions remain in this fascinating field, some of which arise out of this in-depth analysis of the interaction of light with crystal arrays. More types of organic crystals will probably be discovered, as well as other organisms that use these crystals to manipulate light. The insights gained from biological systems can also be harnessed for improving synthetic light-manipulating materials.

Advanced quantum and semiclassical methods for simulating photoinduced molecular dynamics and spectroscopy

AbstractMolecular‐level understanding of photoinduced processes is critically important for breakthroughs in transformative technologies utilizing light, ranging from photomedicine to photoresponsive materials. Theory and simulation play a crucial role in this task. Despite great advances in hardware and computational methods, the theoretical description of photoinduced phenomena in the presence of complex environments and external photoexcitation conditions still poses formidable challenges for theoreticians and there are numerous formal and computational difficulties that must be overcome. The development of predictive, accurate, and at the same time, computationally efficient theoretical approaches to describe complex problems in photochemistry and photophysics is an active field of research in contemporary theoretical and computational chemistry. In this advanced review, we discuss modern computational advances and novel approaches that have been recently developed in excited‐electronic structure methods, and multiscale modeling, with a special emphasis on coupled electron‐nuclear dynamics and spectroscopy, from fully quantum to semi‐classical methodologies—including dissipative effects, the explicit light field interaction, femtosecond time‐resolved spectroscopy, and software infrastructure.This article is categorized under: Software > Quantum Chemistry Electronic Structure Theory > Combined QM/MM Methods Theoretical and Physical Chemistry > Spectroscopy Software > Molecular Modeling

Perspective on Quantum Sensors from Basic Research to Commercial Applications

Quantum sensors represent a new generation of sensors with improved precision, accuracy, stability, and robustness to environmental effects compared to their classical predecessors. After decades of laboratory development, several types of quantum sensors are now commercially available or are part-way through the commercialization process. This paper provides a brief description of the operation of a selection of quantum sensors that employ the principles of atom–light interactions and discusses progress toward packaging those sensors into products. This paper covers quantum inertial and gravitational sensors, including gyroscopes, accelerometers, gravimeters, and gravity gradiometers that employ atom interferometry, nuclear magnetic resonance gyroscopes, atomic and spin-defect magnetometers, and Rydberg electric field sensors.

Deep SVBRDF Acquisition and Modelling: A Survey

AbstractHand in hand with the rapid development of machine learning, deep learning and generative AI algorithms and architectures, the graphics community has seen a remarkable evolution of novel techniques for material and appearance capture. Typically, these machine‐learning‐driven methods and technologies, in contrast to traditional techniques, rely on only a single or very few input images, while enabling the recovery of detailed, high‐quality measurements of bi‐directional reflectance distribution functions, as well as the corresponding spatially varying material properties, also known as Spatially Varying Bi‐directional Reflectance Distribution Functions (SVBRDFs). Learning‐based approaches for appearance capture will play a key role in the development of new technologies that will exhibit a significant impact on virtually all domains of graphics. Therefore, to facilitate future research, this State‐of‐the‐Art Report (STAR) presents an in‐depth overview of the state‐of‐the‐art in machine‐learning‐driven material capture in general, and focuses on SVBRDF acquisition in particular, due to its importance in accurately modelling complex light interaction properties of real‐world materials. The overview includes a categorization of current methods along with a summary of each technique, an evaluation of their functionalities, their complexity in terms of acquisition requirements, computational aspects and usability constraints. The STAR is concluded by looking forward and summarizing open challenges in research and development toward predictive and general appearance capture in this field. A complete list of the methods and papers reviewed in this survey is available at computergraphics.on.liu.se/star_svbrdf_dl/.

A Polymeric Two-in-One Electron Transport Layer and Transparent Electrode for Efficient Indoor All-Organic Solar Cells.

Transparent electrodes (TEs) are vital in optoelectronic devices, enabling the interaction of light and charges. While indium tin oxide (ITO) has traditionally served as a benchmark TE, its high cost prompts the exploration of alternatives to optimize electrode characteristics and improve device efficiencies. Conducting polymers, which combine polymer advantages with metal-like conductivity, emerge as a promising solution for TEs. This work introduces a two-in-one electron transport layer (ETL) and TE based on films of polyethylenimine ethoxylated (PEIE)-modified poly(benzodifurandione) (PBFDO). These PEIE-modified PBFDO layers exhibit a unique combination of properties, including low sheet resistance (130 Ω sq-1), low work function (4.2 eV), and high optical transparency (>85% in the UV-vis-NIR range). In contrast to commonly used poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), the doping level of PBFDO remains unaffected by the PEIE treatment, as verified through UV-vis-NIR absorption and X-ray photoelectron spectroscopy measurements. When employed as a two-in-one ETL/TE in organic solar cells, the PEIE-modified PBFDO electrode exhibits performance comparable to conventional ITO electrodes. Moreover, this work demonstrates all-organic solar cells with record-high power conversion efficiencies of >15.1% under indoor lighting conditions. These findings hold promise for the development of fully printed, all-organic optoelectronic devices.

Fabricated ZnIn2S4/Cu2S S-scheme heterojunction with snowflake structure for boosting photocatalytic CO2 reduction in gas–solid reactor

Designing S-scheme heterojunctions has become a powerful strategy to enhance photocatalytic activity and improve the localization of catalyst surface charge. Therefore, more and more research has been devoted to S-scheme heterojunctions. In this work, we employed a simple two-step hydrothermal method to fabricate S-scheme ZnIn2S4/Cu2S (ZIS/Cu2S) heterojunctions. The results show that the composites exhibit good performance in the photoreduction of CO2 to CO and CH4. Especially, at 40 %-ZIS/Cu2S, the release rates of CO and CH4 were 13.35 μmol g−1 and 34.81 μmol g−1 under the condition of a 4 h reaction, and the selectivity of CH4 reached 80 %. In addition, the in situ FTIR test revealed that the catalyst promoted the formation of the key intermediates COOH* and CH3O* under the effect of light interaction, which was favorable to the photoreduction of CO2. This indicates that the electron transfer path of S-type not only promotes the separation of carriers for conversion but also has a strong redox ability to selectively convert CO2 to CH4, which provides some thoughts for the design of S-scheme heterojunction photocatalysts. This provides some thoughts for the design of S-scheme heterojunction photocatalysts.

Innovative Thin PiG Plates Boost the Luminous Efficacy and Reliability of WLEDs for Vehicles

In this study, we demonstrate the high luminous efficacy of 118 lm/W and the high reliability of white LEDs (WLEDs) through 450 °C thermal aging, utilizing four-inch YAG: Ce3+ phosphor-in-glass (PiG) plates designed for vehicle headlights. The sintering process of mixing glass and phosphor typically generates pores, which can scatter light and reduce the luminous efficacy of the fabricated PiG. In this study, we produced four-inch PiG plates under four different fabrication conditions to evaluate their luminous efficacy. Our results revealed that the PiG plate with a thin thickness of 0.08 mm exhibited a 16.83% increase in luminous efficacy compared to the 0.15 mm plate, attributed to reduced light interaction with the pores. Unlike silicone-based phosphor WLEDs, which offer high performance but lower reliability due to the silicone resin’s low transition temperature (150 °C), our novel thin PiG plate achieves high performance and reliability. This advancement suggests that the proposed thin PiG plate could replace traditional silicone-based phosphors, enabling the development of high-quality WLEDs for vehicle headlights in automotive applications.

How to find optimal quantum states for optical micromanipulation and metrology in complex scattering problems: tutorial

The interaction of quantum light with matter is of great importance to a wide range of scientific disciplines, ranging from optomechanics to high-precision measurements. A central issue we discuss here, is how to make optimal use of both the spatial and the quantum degrees of freedom of light for characterizing and manipulating arbitrary observable parameters in a linear scattering system into which suitably engineered light fields are injected. Here, we discuss a comprehensive framework based on a quantum operator that can be assembled solely from the scattering matrix of a system and its dependence on the corresponding local parameter, making this operator experimentally measurable from the far field using only classical light. From this, the effect of quantum light in the near field, i.e., in the vicinity of the target object, can be inferred. Based on this framework, it is straightforward to formulate optimal protocols on how to jointly design both the spatial shape and the quantum characteristics of light for micromanipulation as well as for parameter estimation in arbitrarily complex media. Also, the forces of the quantum vacuum naturally emerge from this formalism. The aim of our tutorial is to bring different perspectives into alignment and thereby build a bridge between the different communities of wave control, quantum optics, micromanipulation, quantum metrology, and vacuum physics.

Photocatalytic performance of Soot/TiO2 nanocomposite against toxic dye

Nowadays, composing semiconductors with carbon structures to enhance their optical properties shows huge interest as a nanophotocatalyst for trending applications (i.e., photodegrading pollutants). In this study, TiO2 and soot/TiO2 nanocomposites were prepared via a one-step sol-gel assisted hydrothermal method, using a temperature of 220 °C and a reaction time of 6 h. Characterization by X-ray diffraction and Raman spectroscopy confirmed that the resulting TiO2 and soot/TiO2 materials exhibited a pure anatase crystal phase, without the presence of other TiO2 polymorphs. Soot composition on TiO2 showed enhanced photocatalysis properties, such as a lower combination rate of electron-hole pairs than pure TiO2. Crystal violet (CV) was applied as a pollutant model to examine the photocatalytic degradation of synthesized TiO2 and soot/TiO2. The photodegradation experiments of CV dye in its aqueous media by UV light interaction showed 26.63 % and 89.09 % in the presence of TiO2 and soot/TiO2 nanocomposite, respectively. In the basic media (pH 11), maximum photodegradation (97.95 %) is attained when 0.004 g of Photocatalyst (soot/TiO2) is used. Using the recycled photocatalyst, the dye's photodegradation efficiency remained high throughout the reusability cycles, even after four consecutive cycles.