Interpreting measured absorption spectroscopy data can require repeated simulations of the expected absorption spectrum to fit the data. In cases of high temperature or broadband spectra, the computational load of the spectral analysis can be expensive due to the large number of individual absorption transitions that contribute to each simulation. We present a Graphics Processing Unit (GPU) Accelerated

The study examines the average transmittance of Gaussian beams passing through various biological tissues, taking into account the impact of turbulence, absorption, and scattering. The extended Huygens-Fresnel technique, which utilizes the power spectrum of turbulent biological tissues, is applied to determine the optical intensity at the observation point. Additionally, there are tabulated absorption

The optical constants of fiber materials are of great value in the study of the mechanism and application of radiation regulation, but the conventional methods for obtaining the optical constants of fiber materials suffer from a series of problems such as compositional differences, chemical residues, and microstructural damages, which make it difficult to obtain the optical constants of the fiber materials

The model of a special beam array called multi-cosine-Lorentz correlated (MCLC) beam is introduced, and the coherence function of a MCLC source is related to the multi-cosine function and Lorentz function. The expressions of a MCLC beam in anisotropic oceanic turbulence are derived. Based on the obtained equations, the intensity shapes of a MCLC beam with small δ will become a beam array composed of

Underwater polarization imaging technology has important application prospects in marine scientific research, seabed resource exploration, seabed topography drawing, underwater archaeology and other fields. However, underwater polarization images are subject to degradation in image quality during the acquisition process due to occlusion by water grass, fish, and the absorption of water particles in

We solve the electrostatic boundary problems of a dielectric or conducting hemispheroid (half-spheroid) under arbitrary excitation. The solutions are obtained by expanding the potentials as series of spheroidal harmonics, and integrating over the boundary to obtain matrix equations which can be used to solve for the coefficients. The solutions are used to derive the capacity, polarizability and spatial

The radial quadrature method is proposed recently for evaluating the beam shape coefficients (BSCs) of shaped beams, in which the BSCs are expressed in terms of integrals, infinite series and finite series as well. Previous study reveals that the BSCs expressed in finite series agree exactly with those obtained in the finite series technique and show blowing-ups for high-order partial waves, while

The optical properties of semi-transparent components used as multifunctional coatings or in various non-imaging devices are not always completely known a priori. The quality of plastic covers used in night sky brightness monitors, such as Sky Quality Meter (SQM), can deteriorate with age, causing initially transparent windows to become semi-transparent media that absorb and scatter light. We demonstrate

A determination of the hyperfine structure constants of high lying energy levels of the Niobium (Nb) atom was performed using Fourier-transform spectra. The results obtained complete previous investigations using mainly laser spectroscopy [JQSRT (2020) 245, 106871, 106872, 106873]. In the present work, the hf constants A of altogether 144 levels could be determined, among them 55 levels for which these

Development of a new ultraviolet (UV) laser absorption diagnostic has enabled the probing of nitric oxide (NO) in the second excited vibrational state (v” = 2) for inferences of quantum-state-specific number density and vibrational temperature time-histories. Spectroscopic modeling informed the selection of the new 246.3222 nm wavelength, as this wavelength exhibits high sensitivity for thermometry

A modeling of the photoplasma in a slab cell filled with a sodium vapor and argon mixture one-sided irradiated by a uniform radiation flux was carried out. This study was performed for a spatially heterogeneous distribution of the resonance level density, unlike our previous works. An analytical form of this distribution for the slab available in the literature was used. The present investigation was

Four spectra of methane in natural isotopic abundance in the 900–1050 cm-1 region were recorded using a Fourier transform spectrometer in Tomsk, Russia, with long optical paths 167 m and 1058 m at temperatures 28 and 51 °C. Line positions and intensities were retrieved by non-linear least-squares curve-fitting procedures and analyzed using effective Hamiltonian and effective dipole moment models. The

The paper presents the results of measurements of the hyperfine structure for electronic levels belonging to odd configurations in the terbium atom with a small quantum number J. Laser spectroscopy with laser-induced fluorescence detection was used in the measurements. The hyperfine structure of 32 terbium lines was measured in three spectral regions. The hyperfine structure constants were determined

T-matrix methods, with incident and scattered fields described as sums of multipolar fields, are attractive computational methods for many scattering problems due to their versatility, accuracy, and computational efficiency, especially for repeated calculations. However, numerical difficulties often hamper their use for non-spherical particles with large aspect ratios. Further, even if far-field scattering

Sample properties such as shape and size can be studied via light scattering, if the material complex refractive index is known. A numerical method which utilizes laboratory measurements for deriving the complex refractive index of a mm-sized single particle is introduced. The laboratory measurements are carried out using a 4π scatterometer that measures the intensity of polarized light scattered from

Understanding and accounting for quantum effects in nanoplasmonics is essential for accurate modeling and design of nanophotonic devices. In this paper, we investigate the influence of such quantum effects as spatial nonlocality and splitting of the wave function of conduction electrons near the surface of plasmonic nanoparticles on the extinction cross-section and the field enhancement factor. We

Diatomic species play a pivotal role in complex media, such as the interstellar and circumstellar media. Furthermore, there is a notable lack of information regarding NaC and its ions, NaC+ and NaC−, despite the pervasiveness of the carbon element (C) and the validated role of Na-bearing molecules as organic reagents or in catalytic processes. In this study, ab initio multi-reference calculations,

Resonance ionization mass spectroscopy using three-step photoionization (PI) schemes was employed to study the 642 nm transition of Lu I. Multimode tunable dye lasers were used in these studies to confirm the transition and further characterization of its hitherto unreported hyperfine structure. The hyperfine features of less abundant isotope 176Lu and hyperfine A constant of upper level of 642 nm

About two decades ago, very unusual highly-resolved x-ray spectra were observed using a femtosecond laser-produced plasma that included a new type of satellite lines identified as being emitted from the autoionizing states of hollow ions (such as, for example, exotic KK hollow ions with the empty K shell). Though atomic structure calculations were able to predict the locations of such newly observed

Fifteen transitions of the 20012-00001 band of 13CO2 in air have been recorded at 296 K using a cavity ring-down spectrometer linked to an optical frequency comb referenced to a GPS-disciplined Rb oscillator. In parallel, measurements of 12CO2 in air were made with a Fourier transform spectrometer for transitions belonging to the same 20012-00001 band, enabling comparison of the air-induced half-width

A high-level ab initio computation has been performed in order to determine the molecular structures, electronic characters and transition properties of a hitherto unknown diatomic cation of NaAs+. The electronic states associated with five dissociation channels, including both the Na++As and Na+As+ limits, are subjected to detailed analysis. The results of the potential energy functions, spectroscopic

The aerosol particles are positively associated with the cloud parameters, precipitation and radiation budgets. The correlations of the aerosols-clouds-precipitations interaction ACPI are uncertain, that show large spatiotemporal variability in their magnitude. For this study, the aerosol particles and clouds data were retrieved from the Moderate Resolution Imaging Spectroradiometer MODIS sensors.

Nonreciprocal thermal emitters that break Kirchhoff’s law of thermal radiation promise exciting applications for thermal and energy applications. The design of the bandwidth and angular range of the nonreciprocal effect, which directly affects the performance of nonreciprocal emitters, typically relies on physical intuition. In this study, we present a general numerical approach to maximize the nonreciprocal

The infrared spectrum of mono-silane was measured at varied experimental conditions with a Bruker Fourier transform infrared spectrometer IFS125HR and analyzed for the first time in the 2600–2950 cm−1 region of the octad where 16 strongly interacting triply excited bending bands are located. The 3505 transitions belonging to fourteen sub-bands of the octad (with the exception of unappeared 3ν4(A1)

Understanding the radiative transfer processes in the Earth’s atmosphere is crucial for accurate climate modeling and climate change predictions. These processes are governed by complex physical phenomena, which can be generally modeled by the radiative transfer equation (RTE). Solutions to the RTE are obtained by various methods including numerical (standard RTE solvers), stochastic (Monte-Carlo)

This study aimed to establish a steady-state and time-domain solutions for the approximate P3 equation in arbitrary multi-layer slab media for light propagation, based on a diffusion model with an isotropic point source in the first layer and extrapolated boundary conditions. Spatially resolved diffuse reflectance and transmittance were calculated using the steady-state approximation of the P3 equation

We present an update to the Granada–Amsterdam Light Scattering Database (https://scattering.iaa.es/), which includes experimental data from both the IAA-Cosmic Dust Laboratory in Granada and the Amsterdam light scattering setup. The updated version features an expanded collection of samples and a more user-friendly interface. We have extended the size range of our mineral samples to mm-cm-sized single

Herein, we derive the expression for the atmospheric refractive index structure constant under the influence of planar acoustic wave perturbations under the influence of the acoustic field on the refractive index and energy of the atmosphere. Utilizing the low-frequency compensated power spectrum inversion technique, we simulate the refractive index power spectrum of atmospheric turbulence perturbed

Line-shape parameters for self-broadened CO2 transitions are predicted for temperatures ranging from 296 K to 1250 K, using requantized molecular dynamics simulations (rCMDS). The line broadening coefficient, the speed dependence component and the first-order line-mixing coefficient for lines with rotational quantum number from 2 to 100, have been determined from fits of the rCMDS spectra with the

The N2-, O2, and air-broadened halfwidths of CH3CN lines in the parallel ν4 band have been calculated, along with the relaxation matrices W. These calculations employ our modified and refined versions of the Robert-Bonamy formalism and use all potential parameters from the literature without adjustments. Extensive comparisons between the predicted N2-broadened halfwidths in the qR and qP branches from

We analyze the predictions of two recently developed effective-medium approximations for the effective refractive index of a system of either transparent or plasmonic spherical particles, dispersed randomly in a transparent liquid matrix, as a function of their geometrical and physical parameters. The importance and significance of these approximations is that besides the radiative corrections to the

A Rayleigh mixing rule that relates the effective imaginary part of the refractive index of a composite medium, such as an aerosol or colloid, to the complex refractive index of the Rayleigh particles is derived using Rayleigh scattering theory. The derivation is simple, straightforward, and only weakly dependent on particle morphology. The Rayleigh mixing rule offers an opportunity to derive the imaginary

Under a general approximation of multiple scattering paths involving small-angle scatterings interspersed with occasional large-angle scatterings, we performed Monte Carlo vector radiative transfer simulations to investigate the spatial and temporal distribution of the reduced Mueller matrix (RMM) of lidar returns from water clouds. Our findings indicate that the normalized RMM elements M̃22′ and M̃33′

LiDB is a database of molecular radiative lifetimes (Owens et al., 2023), created to aid in the modelling of radiative effects in low-temperature plasmas. Here, we report the addition of atomic radiative lifetimes to LiDB. Datasets are generated for neutral and singly-charged atomic species based on energy levels, transitions, and transition probabilities extracted from the National Institute of Standards

Our objective is to provide reliable Stark broadening data for Sn II spectral lines needed for astrophysics, plasma physics, fusion research, and different plasmas in laboratory and technology. We used the semiclassical perturbation method for the calculation of Stark broadening parameters, full widths at half intensity maximum and shifts for 44 spectral lines of singly charged tin ion (Sn II), for

In this study, we propose an innovative design for nanoporous Si thin film (NPTF) solar cell, seamlessly integrated with semiconducting (CdSe)ZnS Quantum Dots (QDs), without the need for additional metal-dielectric interfaces to attain plasmonic like effects. The intricate network of randomized nano-scaled pores within thin film creates similar enhancement, complemented by QDs inducing excitonic resonances

In this work, Mie theory is employed to study the opto-thermal response of magneto plasmonic Fe/Co/Ni@Au and Fe/Co/Ni@Ag core-shell nanostructures of different sizes in the presence of dielectric media (i.e., water) is investigated numerically. The optical and thermal characteristics from the Fe, Co, and Ni as core material with noble metal Au and Ag as coating (shell) material are susceptible to being

A comprehensive semi-classical study of the collisional line broadening and shift coefficients of C2H2 by several key perturbers (H2, He, N2, C2H2, CO, and CO2) for astronomical applications using the Complex Robert–Bonamy–Ma (CRBM) framework is presented. Following the CRBM computational protocol, the intermolecular interaction potentials are constructed from atom–atom and electrostatic interactions

Synchrotron radiation has been used to record for the first time absolute vacuum ultraviolet photoabsorption cross-sections of trifluoroacetic acid (TFA) and chlorodifluoroacetic acid (CDFA) in the 4.5–10.8 eV energy range. In order to further our knowledge of the major electronic transitions and thus help interpret the photoabsorption data, theoretical calculations using time-dependent density functional

The circular intensity differential scattering (CIDS), which is the normalized Mueller matrix element -S14/S11, has been measured from single biological particles as a function of scattering angle. CIDS is valuable for its potential in detecting chiral particles that may include the helical structures of DNA or RNA molecules in biological samples, and as such is a potential method for detecting biological

A mathematical method to enable absorption cross-section measurements using an optical cell with a non-uniform temperature distribution is formulated, validated and experimentally demonstrated in this study. The motivation of the proposed method is to facilitate high-temperature spectroscopic studies in the long-wavelength mid-IR region, and to offer an alternative to highly engineered optical cells

Preparation of metastable Kr atoms in the 5s[3/2]2 level via laser-induced ionization has been achieved. The temporal evolution of the intensity of Kr atomic spectral lines at 760.15 nm, 811.29 nm, and 431.96 nm was used to elucidate the production mechanisms of metastable Kr atoms. These mechanisms primarily involve two processes: the “excitation + radiation” process, dominated by multiphoton excitation

Hyperspectral absorption tomography has emerged as a promising technique for combustion diagnostics due to its rich spectral measurements. However, the non-linear and ill-posed nature of the inverse problem makes obtaining accurate results challenging. This paper proposes a novel application of a physics-informed neural network to address the non-linear inverse problem in hyperspectral absorption spectroscopy

The Collision-Induced Absorption (CIA) fundamental band of H2 has been studied in the 3600–5500 cm−1 spectral range for temperatures ranging from 120 to 500 K for both a pure H2 gas and a H2-He mixture. We used a simulation chamber called PASSxS (Planetary Atmosphere System Simulation x Spectroscopy) developed at INAF/ISAC which contains a Multi-Pass cell interfaced with a Fourier Spectrometer, aligned

Evaluation of the Voigt function, a convolution of a Lorentzian and a Gaussian profile, is essential in various fields such as spectroscopy, atmospheric science, and astrophysics. Efficient computation of the function is crucial, especially in applications where the function may be called for an enormous number of times. In this paper, we present a highly efficient novel algorithm and its Fortran90

Microdispersed photocatalysts based on titanium dioxide (TiO2) in the form of hollow core-shell microspheres (microcapsules) with mesoporous structure are widely demanded in modern critical technologies related to the catalysis of various chemicals, solving environmental problems, and obtaining cheap fuel. To date, a number of experimental works are known, showing that geometrical parameters of microcapsules

This study introduced a new model for quantitative analysis of the state-resolved laser-induced fluorescence signal of diatomic molecules, namely StaR-LIF. This model is built upon a master equation of the collisional-radiative transfer processes, which incorporated the latest data on the collisional energy transfer rates between individual spin- and parity-resolved rovibronic quantum levels, together

We consider radiative transfer and coherent backscattering (RT-CB) in a discrete random medium of particles. The elementary scattering matrix of the medium conforms to the ensemble-averaged scattering matrix for nonspherical particles and their mirror particles, both in random orientation. We express the ensemble-averaged matrix, via spectral decomposition, as a linear superposition of four pure Mueller

The present study uses a high-resolution Fourier Transform Spectrometer to provide data on the spectral line measurements of atomic bromine (Br I) in the 6000 – 12,000 cm‒1 range in the near-infrared spectral region. Bromine electrodeless discharge lamps (EDL) were prepared and utilized as light sources, while light detectors comprised InGaAs and Si diodes. A total of 302 spectral lines were detected

This manuscript investigates the electronic structures, spectral properties, and photoionization processes of the confined atomic system. For this purpose, a relativistic methodology employing the Dirac–Coulomb Hamiltonian within the context of relativistic configuration interaction is suggested, utilizing independent particle basis wavefunctions. The key idea of this approach is to place the atom

The T-matrix for electromagnetic scattering is most commonly computed using the Extended Boundary Condition Method (EBCM), but this approach is numerically unstable for finite cylinders of high aspect ratio. In the electrostatics limit, we show that this instability is caused by catastrophic cancellations in the numerical calculations of oscillatory integrals. We find that the problematic integrals

This paper presents a comprehensive simulation approach for the temperature-dependent Raman spectra of CO2, a common product in combustion and reactive environments. Previous studies have typically been limited to isotropic scattering or a restricted number of energy levels. In contrast, our simulation incorporates both isotropic and anisotropic scattering, including all ro-vibrational O, P, Q, R,

The "GF Special Project" is a massive remote sensing technology initiative including a number of satellites and various observation platforms. GF-5 is the satellite with the most payloads, the highest spectral resolution, and the most difficulty in development, and it can monitor a variety of environmental elements using spatial heterodyne spectroscopy (SHS) technology, including atmospheric aerosols

Ionization cross sections are studied for energy levels of the ground configurations of the Ne3+ and Ne4+ ions. The distorted wave (DW) approximation is used to analyze experimental data. The scaled DW cross sections are used to explain measurements for the Ne3+ ion. Study includes analysis of contributions from the direct and indirect ionization processes. Convergences of excitation-autoionization

Optical Emission Spectroscopy is used within the LIBS (Laser-Induced Breakdown Spectroscopy) technique to measure the elemental composition of a sample irradiated by a laser pulse. When the objective is to characterize a known alloy or to analyze the sample semi-quantitatively, standards can be used. This method refers to the “calibrated LIBS”. When the studied sample is complex (for instance unknown

Laser-Induced Fluorescence (LIF) is an essential optical diagnostic technique for the high-resolution and low-uncertainty measurement of combustion species concentration in a variety of applications and conditions. Two different calibration techniques are explored in this study to obtain quantitative Nitric Oxide (NO) concentration measurements in flames. The first technique, the most employed in the

Understanding the radiative properties of particles is essential for interpreting and analyzing atmospheric remote sensing, target detection, combustion diagnostics, etc. At present, there is a relative lack of studies and understanding of the radiative properties of large aggregate particles. In this work, we comprehensively investigate the radiative properties of large dust aggregate particles via