Pub Date : 2024-11-13DOI: 10.1016/j.jqsrt.2024.109259
O.N. Ulenikov , O.V. Gromova , E.S. Bekhtereva , N.I. Nikolaeva , C. Sydow , S. Bauerecker
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 and ) were assigned () and theoretically analyzed in the frame of the effective Hamiltonian model. The obtained set of 139 fitted parameters reproduces the initial 3505 experimental line positions with the cm−4. A list of assigned experimental transitions is presented as the Supplementary data 2 to this paper.
{"title":"First comprehensive high resolution study of the 28SiH4 octad bending bands","authors":"O.N. Ulenikov , O.V. Gromova , E.S. Bekhtereva , N.I. Nikolaeva , C. Sydow , S. Bauerecker","doi":"10.1016/j.jqsrt.2024.109259","DOIUrl":"10.1016/j.jqsrt.2024.109259","url":null,"abstract":"<div><div>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<sup>−1</sup> 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 <span><math><mrow><mn>3</mn><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub><mrow><mo>(</mo><msub><mrow><mi>A</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>)</mo></mrow></mrow></math></span> and <span><math><mrow><mn>3</mn><msub><mrow><mi>ν</mi></mrow><mrow><mn>2</mn></mrow></msub><mrow><mo>(</mo><msub><mrow><mi>A</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>)</mo></mrow></mrow></math></span>) were assigned (<span><math><mrow><msup><mrow><mi>J</mi></mrow><mrow><mtext>max</mtext></mrow></msup><mo>=</mo><mn>20</mn></mrow></math></span>) and theoretically analyzed in the frame of the effective Hamiltonian model. The obtained set of 139 fitted parameters reproduces the initial 3505 experimental line positions with the <span><math><mrow><msub><mrow><mi>d</mi></mrow><mrow><mtext>rms</mtext></mrow></msub><mo>=</mo><mn>7</mn><mo>.</mo><mn>3</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span> cm<sup>−4</sup>. A list of assigned experimental transitions is presented as the Supplementary data 2 to this paper.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"331 ","pages":"Article 109259"},"PeriodicalIF":2.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142696418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.jqsrt.2024.109252
O. Muñoz , E. Frattin , J. Martikainen , D. Guirado , M. Passas-Varo , J. Escobar-Cerezo , F.J. García-Izquierdo , J.C. Gómez-Martín , Z. Gray , T. Jardiel , F. Moreno , A.J. Ocaña , M. Peiteado , A.T. Gallego-Calvente , H. Volten
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 particles. Additionally, we have added the diffuse reflectance spectra of some of our powder samples and, from these spectra, obtained the corresponding refractive indices (200 nm–2000 nm). We have also incorporated synthetic scattering matrices defined across the entire scattering angle range (0° to 180°) for most of the powder samples contained in the database. Data in the database are freely available under the request of citation of this paper and the paper in which the data are published.
{"title":"Update Granada–Amsterdam Light Scattering Database","authors":"O. Muñoz , E. Frattin , J. Martikainen , D. Guirado , M. Passas-Varo , J. Escobar-Cerezo , F.J. García-Izquierdo , J.C. Gómez-Martín , Z. Gray , T. Jardiel , F. Moreno , A.J. Ocaña , M. Peiteado , A.T. Gallego-Calvente , H. Volten","doi":"10.1016/j.jqsrt.2024.109252","DOIUrl":"10.1016/j.jqsrt.2024.109252","url":null,"abstract":"<div><div>We present an update to the Granada–Amsterdam Light Scattering Database (<span><span>https://scattering.iaa.es/</span><svg><path></path></svg></span>), 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 particles. Additionally, we have added the diffuse reflectance spectra of some of our powder samples and, from these spectra, obtained the corresponding refractive indices (200 nm–2000 nm). We have also incorporated synthetic scattering matrices defined across the entire scattering angle range (0° to 180°) for most of the powder samples contained in the database. Data in the database are freely available under the request of citation of this paper and the paper in which the data are published.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"331 ","pages":"Article 109252"},"PeriodicalIF":2.3,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.jqsrt.2024.109245
Xichang Wang
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, whereas temporally resolved diffuse reflectance and transmittance were derived from the time-domain approximation. The validity of the approximate P3 solutions was confirmed by comparing their results with Monte Carlo simulations. In steady-state analysis, the approximate P3 equation demonstrated superior accuracy to the diffusion equation for reflectance, particularly at smaller thicknesses. Accuracy further improved as the absorption coefficient and detection distance increased. For transmittance, the approximate P3 equation closely matched the diffusion equation at low thickness, but divergence occurred with higher absorption. In time-domain analysis, the approximate P3 equation aligned closely with Monte Carlo simulations at peak values, while its numerical values were close approximations of the diffusion equation away from the peak. The potential application of the approximate P3 equation in multi-layer media offers significant advancements for optical non-invasive detection and treatment techniques, enabling the extraction of optical parameters from such media.
{"title":"Approximate P3 equation analysis in multi-layer slab media: Steady-state and time-domain based on the diffusion model","authors":"Xichang Wang","doi":"10.1016/j.jqsrt.2024.109245","DOIUrl":"10.1016/j.jqsrt.2024.109245","url":null,"abstract":"<div><div>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, whereas temporally resolved diffuse reflectance and transmittance were derived from the time-domain approximation. The validity of the approximate P3 solutions was confirmed by comparing their results with Monte Carlo simulations. In steady-state analysis, the approximate P3 equation demonstrated superior accuracy to the diffusion equation for reflectance, particularly at smaller thicknesses. Accuracy further improved as the absorption coefficient and detection distance increased. For transmittance, the approximate P3 equation closely matched the diffusion equation at low thickness, but divergence occurred with higher absorption. In time-domain analysis, the approximate P3 equation aligned closely with Monte Carlo simulations at peak values, while its numerical values were close approximations of the diffusion equation away from the peak. The potential application of the approximate P3 equation in multi-layer media offers significant advancements for optical non-invasive detection and treatment techniques, enabling the extraction of optical parameters from such media.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"331 ","pages":"Article 109245"},"PeriodicalIF":2.3,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142696421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.jqsrt.2024.109253
Shai Zucker , Dmitry Batenkov , Michal Segal Rozenhaimer
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), and data-driven (machine-learning) approaches. This paper introduces a novel numerical approach utilizing a Physics-Informed Neural Network (PINN) to solve the RTE in atmospheric scenarios, applying physics constraints in a machine-learning framework. We show that our PINN model offers a flexible and efficient solution, enabling the simulation of radiance values using plane-parallel atmosphere, and under diverse conditions, including clouds and aerosols.
{"title":"Physics-informed neural networks for modeling atmospheric radiative transfer","authors":"Shai Zucker , Dmitry Batenkov , Michal Segal Rozenhaimer","doi":"10.1016/j.jqsrt.2024.109253","DOIUrl":"10.1016/j.jqsrt.2024.109253","url":null,"abstract":"<div><div>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), and data-driven (machine-learning) approaches. This paper introduces a novel numerical approach utilizing a Physics-Informed Neural Network (PINN) to solve the RTE in atmospheric scenarios, applying physics constraints in a machine-learning framework. We show that our PINN model offers a flexible and efficient solution, enabling the simulation of radiance values using plane-parallel atmosphere, and under diverse conditions, including clouds and aerosols.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"331 ","pages":"Article 109253"},"PeriodicalIF":2.3,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142696420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-08DOI: 10.1016/j.jqsrt.2024.109265
Q. Ma , C. Boulet
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 the models at T = 296 K and experimental measurements are presented, showing that our latest model very closely matches the measurements. For the qQ branch, where measurements are unavailable, we compare our N2-broadened halfwidths with the converted air-broadened data from HITRAN 2008, obtaining similarly good agreement. The variation in the j and k dependencies of the N2-broadened halfwidths is discussed in detail. Additionally, the theoretically determined conversion factor from N2- to air-broadening is provided. Finally, based on our theoretical calculations of N2-broadened halfwidths of the qR(j,3) lines at five different temperatures, ranging from 250 K to 350 K, the temperature exponent N is determined and its dependence on j is analyzed.
这些计算采用了我们对罗伯特-博纳米形式主义的修改和完善版本，并使用了文献中的所有电势参数，未作任何调整。在 T = 296 K 时，模型预测的 qR 和 qP 支 N2 扩宽半宽与实验测量结果进行了广泛的比较，结果表明我们的最新模型与测量结果非常接近。对于没有测量数据的 qQ 支，我们将我们的 N2 展宽半宽与来自 HITRAN 2008 的转换空气展宽数据进行了比较，得到了类似的良好一致性。我们详细讨论了 N2 扩增半宽的 j 和 k 依赖性变化。此外，还提供了从 N2-到空气增宽的理论确定的转换系数。最后，根据我们对从 250 K 到 350 K 五种不同温度下 qR(j,3) 线的 N2 扩宽半宽的理论计算，确定了温度指数 N 并分析了它与 j 的关系。
{"title":"The j and k dependencies of N2-, O2-, and air-broadened halfwidths of the CH3CN molecule","authors":"Q. Ma , C. Boulet","doi":"10.1016/j.jqsrt.2024.109265","DOIUrl":"10.1016/j.jqsrt.2024.109265","url":null,"abstract":"<div><div>The N<sub>2</sub>-, O<sub>2</sub>, and air-broadened halfwidths of CH<sub>3</sub>CN lines in the parallel ν<sub>4</sub> 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 N<sub>2</sub>-broadened halfwidths in the qR and qP branches from the models at <em>T</em> = 296 K and experimental measurements are presented, showing that our latest model very closely matches the measurements. For the qQ branch, where measurements are unavailable, we compare our N<sub>2</sub>-broadened halfwidths with the converted air-broadened data from HITRAN 2008, obtaining similarly good agreement. The variation in the j and k dependencies of the N<sub>2</sub>-broadened halfwidths is discussed in detail. Additionally, the theoretically determined conversion factor from N<sub>2</sub>- to air-broadening is provided. Finally, based on our theoretical calculations of N<sub>2</sub>-broadened halfwidths of the qR(j,3) lines at five different temperatures, ranging from 250 K to 350 K, the temperature exponent <em>N</em> is determined and its dependence on j is analyzed.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"330 ","pages":"Article 109265"},"PeriodicalIF":2.3,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-08DOI: 10.1016/j.jqsrt.2024.109264
N.H. Ngo , H. Tran
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 Voigt and speed dependent Voigt profiles. These parameters and their temperature dependence were compared with recent high-quality measurements at both room and high temperatures, showing good agreements for all considered parameters. In particular, this study highlights that the temperature dependence of the speed dependent Voigt line broadening coefficient in the HITRAN database needs to be corrected. Additionally, we demonstrate that the temperature dependence for the speed-dependence of the line broadening differs from that of the line broadening, contrary to the assumption widely used in the literature. These findings confirm the quality of theoretical predictions using rCMDS. The data provided can be used to complete and improve spectroscopic databases for various applications.
{"title":"Line-shape parameters and their temperature dependence for self-broadened CO2 lines in the 296 K- 1250 K range by requantized classical molecular dynamics simulations","authors":"N.H. Ngo , H. Tran","doi":"10.1016/j.jqsrt.2024.109264","DOIUrl":"10.1016/j.jqsrt.2024.109264","url":null,"abstract":"<div><div>Line-shape parameters for self-broadened CO<sub>2</sub> 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 Voigt and speed dependent Voigt profiles. These parameters and their temperature dependence were compared with recent high-quality measurements at both room and high temperatures, showing good agreements for all considered parameters. In particular, this study highlights that the temperature dependence of the speed dependent Voigt line broadening coefficient in the HITRAN database needs to be corrected. Additionally, we demonstrate that the temperature dependence for the speed-dependence of the line broadening differs from that of the line broadening, contrary to the assumption widely used in the literature. These findings confirm the quality of theoretical predictions using rCMDS. The data provided can be used to complete and improve spectroscopic databases for various applications.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"331 ","pages":"Article 109264"},"PeriodicalIF":2.3,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-08DOI: 10.1016/j.jqsrt.2024.109266
Jialin Zhang , Mingjun Wang , Xiaohu Wu , Min Liu
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 by a planar acoustic wave. Numerical analysis is conducted on the transmission characteristics of the vortex light superposition states in atmospheric turbulence perturbed by a plane acoustic wave under different acoustic wave transmission heights, acoustic pressure amplitudes, and frequencies. Results indicate that introducing an acoustic field induces fluctuations in the atmospheric refractive index structure constant, with a more pronounced impact on the refractive index than on energy. Compared with the sole consideration of the impact of the acoustic field on the atmospheric refractive index, incorporating its effect on atmospheric energy results in a decrease in the atmospheric refractive index structure constant. The impact of the acoustic field on atmospheric turbulence is directly proportional to both acoustic pressure amplitude and frequency. The influence of the acoustic field on the transmission properties of the vortex optical superposition state varies with different acoustic transmission distances. Consequently, the transmission characteristics of the vortex light superposition state can be actively modulated according to varying acoustic wave transmission distances. This study offers a theoretical basis for modulating the optical field transmission characteristics via acoustic fields.
{"title":"Transmission characteristics of vortex light superposition in atmospheric turbulence disturbed by plane acoustic waves","authors":"Jialin Zhang , Mingjun Wang , Xiaohu Wu , Min Liu","doi":"10.1016/j.jqsrt.2024.109266","DOIUrl":"10.1016/j.jqsrt.2024.109266","url":null,"abstract":"<div><div>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 by a planar acoustic wave. Numerical analysis is conducted on the transmission characteristics of the vortex light superposition states in atmospheric turbulence perturbed by a plane acoustic wave under different acoustic wave transmission heights, acoustic pressure amplitudes, and frequencies. Results indicate that introducing an acoustic field induces fluctuations in the atmospheric refractive index structure constant, with a more pronounced impact on the refractive index than on energy. Compared with the sole consideration of the impact of the acoustic field on the atmospheric refractive index, incorporating its effect on atmospheric energy results in a decrease in the atmospheric refractive index structure constant. The impact of the acoustic field on atmospheric turbulence is directly proportional to both acoustic pressure amplitude and frequency. The influence of the acoustic field on the transmission properties of the vortex optical superposition state varies with different acoustic transmission distances. Consequently, the transmission characteristics of the vortex light superposition state can be actively modulated according to varying acoustic wave transmission distances. This study offers a theoretical basis for modulating the optical field transmission characteristics via acoustic fields.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"331 ","pages":"Article 109266"},"PeriodicalIF":2.3,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142696422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-07DOI: 10.1016/j.jqsrt.2024.109262
Omar Vázquez-Estrada , Augusto García-Valenzuela , Anays Acevedo-Barrera , Rubén G. Barrera
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 optical response of the particles, they include full dynamic corrections to the field exciting any given particle. We perform this analysis by comparing the values obtained using them with the ones obtained from three well-known and widely used effective-medium approximations: Maxwell Garnett, Maxwell Garnett-Mie and van de Hulst. We provide plots of the real and imaginary parts of the effective index of refraction, for the five approximations considered, for polystyrene and gold nanoparticles of different sizes, as a function of the filling fraction and wavelength, pointing out the relevance of the new predictions, as well as the actual physical processes behind the so-called dependent scattering and what we now call dependent absorption.
我们分析了最近开发的两种有效介质近似方法对随机分散在透明液体基质中的透明或等离子球形粒子系统的有效折射率的预测，它们是粒子的几何和物理参数的函数。这些近似值的重要性和意义在于，除了对粒子光学响应的辐射修正外，它们还包括对激发任何给定粒子的场的全动态修正。我们在进行分析时，将使用这些近似值获得的数值与使用三种著名且广泛使用的有效介质近似值获得的数值进行了比较：Maxwell Garnett、Maxwell Garnett-Mie 和 van de Hulst。我们提供了针对不同尺寸的聚苯乙烯和金纳米粒子，所考虑的五种近似值的有效折射率的实部和虚部与填充分数和波长的函数关系图，指出了新预测的相关性，以及所谓的依附散射和我们现在所说的依附吸收背后的实际物理过程。
{"title":"Analysis of the radiative corrections and dynamic extensions to the local field in the effective refractive index of particle suspensions","authors":"Omar Vázquez-Estrada , Augusto García-Valenzuela , Anays Acevedo-Barrera , Rubén G. Barrera","doi":"10.1016/j.jqsrt.2024.109262","DOIUrl":"10.1016/j.jqsrt.2024.109262","url":null,"abstract":"<div><div>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 optical response of the particles, they include full dynamic corrections to the field exciting any given particle. We perform this analysis by comparing the values obtained using them with the ones obtained from three well-known and widely used effective-medium approximations: Maxwell Garnett, Maxwell Garnett-Mie and van de Hulst. We provide plots of the real and imaginary parts of the effective index of refraction, for the five approximations considered, for polystyrene and gold nanoparticles of different sizes, as a function of the filling fraction and wavelength, pointing out the relevance of the new predictions, as well as the actual physical processes behind the so-called dependent scattering and what we now call dependent absorption.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"331 ","pages":"Article 109262"},"PeriodicalIF":2.3,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142696423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-07DOI: 10.1016/j.jqsrt.2024.109254
Hans Moosmüller , Justin B. Maughan , Prakash Gautam , Christopher M. Sorensen
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 part of refractive index spectra of Rayleigh particles, suspended in a non-absorbing medium with known refractive index spectrum, from an extinction spectrum of the composite medium. However, for this application, the real refractive index spectrum of the particle must be known reasonably well and the imaginary part must be known well enough to decide between two mathematical solutions for it. The Rayleigh mixing rule is compared with widely used mixing rules (i.e., volume, Maxwell Garnett, and Bruggeman mixing rules) and we show that in the small volume fraction regime both the Maxwell Garnet and Bruggeman mixing rules agree with the Rayleigh mixing rule.
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Pub Date : 2024-11-07DOI: 10.1016/j.jqsrt.2024.109256
Zhen Wang
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 and are highly affected by two types of scattering plane randomizations: the overall rotation of scattering planes along multiple scattering paths, and the correlation of the rotation of scattering planes along sub-paths separated by large-angle scatterings. The simulation results reveal that the specific geometries of lidar multiple scattering paths, driven by strong forward-scattering in water clouds, result in the two scattering plane randomizations producing markedly different effects on the linear polarization. This insight not only elucidates the varying decline rates in linearly cross-polarized pattern contrast and linear polarization degree observed in current on-beam lidars but also establishes a basis for analyzing polarized signals in potential future off-beam lidar systems.
{"title":"Impacts of scattering plane randomization on lidar multiple scattering polarization signals from water clouds","authors":"Zhen Wang","doi":"10.1016/j.jqsrt.2024.109256","DOIUrl":"10.1016/j.jqsrt.2024.109256","url":null,"abstract":"<div><div>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 <span><math><msubsup><mrow><mover><mrow><mi>M</mi></mrow><mrow><mo>̃</mo></mrow></mover></mrow><mrow><mn>22</mn></mrow><mrow><mo>′</mo></mrow></msubsup></math></span> and <span><math><msubsup><mrow><mover><mrow><mi>M</mi></mrow><mrow><mo>̃</mo></mrow></mover></mrow><mrow><mn>33</mn></mrow><mrow><mo>′</mo></mrow></msubsup></math></span> are highly affected by two types of scattering plane randomizations: the overall rotation of scattering planes along multiple scattering paths, and the correlation of the rotation of scattering planes along sub-paths separated by large-angle scatterings. The simulation results reveal that the specific geometries of lidar multiple scattering paths, driven by strong forward-scattering in water clouds, result in the two scattering plane randomizations producing markedly different effects on the linear polarization. This insight not only elucidates the varying decline rates in linearly cross-polarized pattern contrast and linear polarization degree observed in current on-beam lidars but also establishes a basis for analyzing polarized signals in potential future off-beam lidar systems.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"330 ","pages":"Article 109256"},"PeriodicalIF":2.3,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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