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Xu K, Arbab MH. Terahertz polarimetric imaging of biological tissue: Monte Carlo modeling of signal contrast mechanisms due to Mie scattering. BIOMEDICAL OPTICS EXPRESS 2024; 15:2328-2342. [PMID: 38633080 PMCID: PMC11019684 DOI: 10.1364/boe.515623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 02/16/2024] [Accepted: 02/27/2024] [Indexed: 04/19/2024]
Abstract
Many promising biomedical applications have been proposed for terahertz (THz) spectroscopy and diagnostic imaging techniques. Polarimetric imaging systems are generally useful for enhancing imaging contrasts, yet the interplay between THz polarization changes and the random discrete structures in biological samples is not well understood. In this work, we performed Monte Carlo simulations of the propagation of polarized THz waves in skin and adipose tissues based on the Mie scattering from intrinsic structures, such as hair follicles or sweat glands. We show that the polarimetric contrasts are distinctly affected by concentration, size and dielectric properties of the scatterers, as well as the frequency and polarization of the incident THz waves. We describe the experimental requirements for observing and extracting these polarimetric signals due to the low energy and small angular spread of the back-scattered THz radiation. We analyzed the spatially integrated Mueller matrices of samples in the normal-incidence back-scattering geometry. We show that the frequency-dependent degree of polarization (DOP) can be used to infer the concentrations and dielectric contents of the scattering structures. Our modeling approach can be used to inform the design of the imaging modalities and the interpretation of the spectroscopic data in future terahertz biomedical imaging applications.
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Affiliation(s)
- Kuangyi Xu
- Department of Biomedical Engineering, State University of New York at Stony Brook, Stony Brook, New York 11794, USA
| | - M. Hassan Arbab
- Department of Biomedical Engineering, State University of New York at Stony Brook, Stony Brook, New York 11794, USA
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2
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Zheng D, Pauporté T, Schwob C, Coolen L. Models of light absorption enhancement in perovskite solar cells by plasmonic nanoparticles. EXPLORATION (BEIJING, CHINA) 2024; 4:20220146. [PMID: 38854487 PMCID: PMC10867376 DOI: 10.1002/exp.20220146] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 06/27/2023] [Indexed: 06/11/2024]
Abstract
Numerous experiments have demonstrated improvements on the efficiency of perovskite solar cells by introducing plasmonic nanoparticles, however, the underlying mechanisms are still not clear: the particles may enhance light absorption and scattering, as well as charge separation and transfer, or the perovskite's crystalline quality. Eventually, it can still be debated whether unambiguous plasmonic increase of light absorption has indeed been achieved. Here, various optical models are employed to provide a physical understanding of the relevant parameters in plasmonic perovskite cells and the conditions under which light absorption may be enhanced by plasmonic mechanisms. By applying the recent generalized Mie theory to gold nanospheres in perovskite, it is shown that their plasmon resonance is conveniently located in the 650-800 nm wavelength range, where absorption enhancement is most needed. It is evaluated for which active layer thickness and nanoparticle concentration a significant enhancement can be expected. Finally, the experimental literature on plasmonic perovskite solar cells is analyzed in light of this theoretical description. It is estimated that only a tiny portion of these reports can be associated with light absorption and point out the importance of reporting the perovskite thickness and nanoparticle concentration in order to assess the presence of plasmonic effects.
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Affiliation(s)
- Daming Zheng
- Sorbonne UniversitéCNRS, Institut de NanoSciences de Paris, INSPParisFrance
- Chimie ParisTechPSL Research UniversityCNRS, Institut de Recherche de Chimie Paris (IRCP), CurieParisFrance
| | - Thierry Pauporté
- Chimie ParisTechPSL Research UniversityCNRS, Institut de Recherche de Chimie Paris (IRCP), CurieParisFrance
| | - Catherine Schwob
- Sorbonne UniversitéCNRS, Institut de NanoSciences de Paris, INSPParisFrance
| | - Laurent Coolen
- Sorbonne UniversitéCNRS, Institut de NanoSciences de Paris, INSPParisFrance
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3
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Zhang S, Zhai J, Dong J, Zhang W, Liu L. Extinction and attenuation by voids in absorbing host media. OPTICS EXPRESS 2023; 31:32214-32226. [PMID: 37859029 DOI: 10.1364/oe.500474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 08/28/2023] [Indexed: 10/21/2023]
Abstract
Extinction and attenuation by particles in an absorbing host have suffered a long-lasting controversy, which has impeded the physical insights on the radiative transfer in the voids dispersed composite. In this paper, we outline the existing extinction definitions, including an equivalence theorem neglecting the host absorption, the near-field analytical definition neglecting the far-field effects, and the operational way which simulates the actual detector readings. It is shown that, under the independent scattering approximation, the generalized operational definition is equivalent to a recent effective medium method according to the rigorous theory of multiple scattering. Using this generalized extinction, we show the important influences of the host absorption on the void extinction. Specifically, at the void resonance, the extinction cross sections of the small voids can be positive, zero, and even negative, which is regulated quantitively by host absorption. Considering the voids in SiC or Ag, the intriguing properties are verified through the attenuation coefficient calculated by the Maxwell-Garnett effective medium theory. In contrast, the equivalent theorem cannot describe any void resonance structures in the absorbing media. Also, the near-field definition fails to generate negative extinction and cannot thus describe the diminished total absorption by the voids. Our results might provide a better understanding of complex scattering theory in absorbing media.
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Loiko NA, Miskevich AA, Loiko VA. Optical characteristics of a monolayer of identical spherical particles in an absorbing host medium. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2023; 40:682-691. [PMID: 37132961 DOI: 10.1364/josaa.476765] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The problem of light interaction with a 2D ensemble of homogeneous spherical particles embedded into an unbounded homogeneous absorbing host medium is considered. Based on the statistical approach, the equations are derived to characterize optical response of such a system with taking into account multiple scattering of light. Numerical data are presented for the spectral behavior of coherent transmission and reflection, incoherent scattering, and absorption coefficients of thin dielectric, semiconductor, and metal films containing a monolayer of particles with various spatial organization. The results are compared with the characteristics of the inverse structure: particles consist of the host medium material and vice versa. Data for the redshift of the surface plasmon resonance of the monolayer of gold (Au) nanoparticles in the fullerene (C 60) matrix are presented as a function of the monolayer filling factor. They are in qualitative agreement with the known experimental results. The findings have potential applications in the development of new electro-optical and photonic devices.
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Khlebtsov NG. Extinction, absorption, and scattering of light by plasmonic spheres embedded in an absorbing host medium. Phys Chem Chem Phys 2021; 23:23141-23157. [PMID: 34617525 DOI: 10.1039/d1cp03057d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Although the general Lorenz-Mie formalism for spheres in an absorbing host has been developed, no correct analytical expressions in the small-particle limit have been published so far. Here, we derive two sets of analytical expressions for the extinction, absorption, and far- and near-field scattering cross sections of small particles embedded in an absorbing host. One set is a modification of the electrostatic approximation (EA) for an absorbing host, whereas the other represents an improved electrostatic approximation (IEA) based on the generalized Lorenz-Mie theory and a new form of Mie coefficients for the internal field expansion. To illustrate the accuracy of the derived approximations, we consider Au and Ag nanospheres embedded in model hosts (real part of the refractive index, 1.33; imaginary part, 0-0.3), in a lossless poly(methyl methacrylate) (PMMA), and a lossy poly(3-hexylthiophene) (P3HT) matrix. In general, the IEA cross sections agree with those calculated using Lorenz-Mie theory if the particle diameter is not greater than 50 nm. Two small-particle limits are found for the near-field scattering cross sections. When host absorption is negligible, the scattering efficiency scales as the fourth power of the size parameter. In contrast, for nonzero absorption, the scattering efficiency scales as the first power of the size parameter. For a spectrally independent host, an increase in host absorption broadens and suppresses plasmonic peaks. We found an exception to this general tendency for near-field scattering by small (10-50 nm) particles; for these, an increase in host absorption increases the scattering peak. This surprising behavior is explained analytically. For 10-30 nm Au particles in the PMMA and P3HT matrixes, the EA and IEA data perfectly agree with the exact Lorenz-Mie simulations, in contrast to the previously reported conclusions. In particular, replacing PMMA with P3HT shifts the plasmonic peaks of the 10 nm particles from 540 nm to 650 nm and strongly enhances near- and far-field scattering. However, far-field scattering does not contribute to the extinction derived from the generalized optical theorem.
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Affiliation(s)
- Nikolai G Khlebtsov
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prospekt Entuziastov, Saratov 410049, Russia. .,Saratov State University, 83 Ulitsa Astrakhanskaya, Saratov 410012, Russia
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6
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Zeng S, Pian S, Su M, Wang Z, Wu M, Liu X, Chen M, Xiang Y, Wu J, Zhang M, Cen Q, Tang Y, Zhou X, Huang Z, Wang R, Tunuhe A, Sun X, Xia Z, Tian M, Chen M, Ma X, Yang L, Zhou J, Zhou H, Yang Q, Li X, Ma Y, Tao G. Hierarchical-morphology metafabric for scalable passive daytime radiative cooling. Science 2021; 373:692-696. [PMID: 34353954 DOI: 10.1126/science.abi5484] [Citation(s) in RCA: 153] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 06/28/2021] [Indexed: 12/12/2022]
Abstract
Incorporating passive radiative cooling structures into personal thermal management technologies could effectively defend humans against intensifying global climate change. We show that large-scale woven metafabrics can provide high emissivity (94.5%) in the atmospheric window and high reflectivity (92.4%) in the solar spectrum because of the hierarchical-morphology design of the randomly dispersed scatterers throughout the metafabric. Through scalable industrial textile manufacturing routes, our metafabrics exhibit desirable mechanical strength, waterproofness, and breathability for commercial clothing while maintaining efficient radiative cooling ability. Practical application tests demonstrated that a human body covered by our metafabric could be cooled ~4.8°C lower than one covered by commercial cotton fabric. The cost-effectiveness and high performance of our metafabrics present substantial advantages for intelligent garments, smart textiles, and passive radiative cooling applications.
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Affiliation(s)
- Shaoning Zeng
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Sijie Pian
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310058, China
| | - Minyu Su
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zhuning Wang
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310058, China
| | - Maoqi Wu
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China.,iFabric Lab, TD Energy, Inc., Weifang 261500, China
| | - Xinhang Liu
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310058, China
| | - Mingyue Chen
- iFabric Lab, TD Energy, Inc., Weifang 261500, China
| | - Yuanzhuo Xiang
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jiawei Wu
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Manni Zhang
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Qingqing Cen
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310058, China
| | - Yuwei Tang
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310058, China
| | - Xianheng Zhou
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310058, China
| | - Zhiheng Huang
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Rui Wang
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Alitenai Tunuhe
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiyu Sun
- iFabric Lab, TD Energy, Inc., Weifang 261500, China
| | - Zhigang Xia
- State Key Laboratory of New Textile Materials and Advanced Processing Technologies, Wuhan Textile University, Wuhan 430200, China
| | - Mingwei Tian
- Research Center for Intelligent and Wearable Technology, College of Textiles and Clothing, State Key Laboratory of Bio-Fibers and Eco-Textiles, Intelligent Wearable Engineering Research Center of Qingdao, Qingdao University, Qingdao 266071, China
| | - Min Chen
- Wuhan National Laboratory for Optoelectronics and School of Computer Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiao Ma
- State Key Laboratory of Biobased Fiber Manufacturing Technology, China Textile Academy, Beijing 110105, China
| | - Lvyun Yang
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jun Zhou
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Huamin Zhou
- State Key Laboratory of Material Processing and Die and Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Qing Yang
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310058, China
| | - Xin Li
- State Key Laboratory of Biobased Fiber Manufacturing Technology, China Textile Academy, Beijing 110105, China
| | - Yaoguang Ma
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310058, China.
| | - Guangming Tao
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China.
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7
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Dong J, Zhang W, Liu L. Discrete dipole approximation method for electromagnetic scattering by particles in an absorbing host medium. OPTICS EXPRESS 2021; 29:7690-7705. [PMID: 33726265 DOI: 10.1364/oe.418467] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 02/17/2021] [Indexed: 06/12/2023]
Abstract
Electromagnetic (EM) scattering by particles in an absorbing host medium is frequently encountered in practical applications, which makes the conventional EM scattering theory controversial and most of the theoretical methods for EM scattering inapplicable. Most of the relevant works in literature are confined to spherical particles. In this work, we develop the discrete dipole approximation (DDA) method for EM scattering by an arbitrary particle immersed in an absorbing host medium. We elaborate how the near- and far-field scattering quantities can be calculated by DDA. The accuracy of DDA is validated by comparison with the apparent and inherent scattering quantities of spherical particles computed by exact Mie theory. Then EM extinction by non-absorbing spheroids in absorbing host medium is studied by DDA. We find that particles that are prolonged in the incident direction are more likely to produce a negative apparent extinction, which is also supported by the near-field electric field distribution. The DDA method we develop will be useful and flexible in the study of EM scattering by particles in absorbing host medium.
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8
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Ivanenko Y, Gustafsson M, Nordebo S. Optical theorems and physical bounds on absorption in lossy media. OPTICS EXPRESS 2019; 27:34323-34342. [PMID: 31878482 DOI: 10.1364/oe.27.034323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 10/10/2019] [Indexed: 06/10/2023]
Abstract
Two different versions of an optical theorem for a scattering body embedded inside a lossy background medium are derived in this paper. The corresponding fundamental upper bounds on absorption are then obtained in closed form by elementary optimization techniques. The first version is formulated in terms of polarization currents (or equivalent currents) inside the scatterer and generalizes previous results given for a lossless medium. The corresponding bound is referred to here as a variational bound and is valid for an arbitrary geometry with a given material property. The second version is formulated in terms of the T-matrix parameters of an arbitrary linear scatterer circumscribed by a spherical volume and gives a new fundamental upper bound on the total absorption of an inclusion with an arbitrary material property (including general bianisotropic materials). The two bounds are fundamentally different as they are based on different assumptions regarding the structure and the material property. Numerical examples including homogeneous and layered (core-shell) spheres are given to demonstrate that the two bounds provide complimentary information in a given scattering problem.
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9
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Wang CC, Ma LX. Effect of host medium absorption on polarized radiative transfer in dispersed media. APPLIED OPTICS 2019; 58:7157-7164. [PMID: 31503989 DOI: 10.1364/ao.58.007157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 08/13/2019] [Indexed: 06/10/2023]
Abstract
This paper focuses on polarized radiative transfer in a thin layer composed of titanium dioxide particles while considering the effect of host medium absorption on particle scattering. The single-scattering properties of particles in an absorbing medium are calculated using the modified Lorenz-Mie program recently developed based on the first-principles theory of electromagnetic scattering, and the vector radiative transfer equation is solved by using the spectral element method. The relative errors of Stokes parameters caused by using the conventional Lorenz-Mie theory are systemically investigated. The results show that neglecting the effect of host medium absorption on particle scattering has a more significant impact on the radiation intensity than the polarization components in most cases. Meanwhile, the relative errors of Stokes parameters induced by using the conventional Lorenz-Mie theory obviously increase with the increase of the host medium absorption index and particle size parameter. Due to the larger scattering coefficients and scattering albedos (i.e., for the case of particle size parameter x=10.0 in this study), the relative errors of Stokes parameters of monodisperse particles are obviously larger than those of polydisperse particles. Moreover, it is found that the relative errors of the Stokes parameters change nonlinearly with the particle volume fraction, especially for large size particles.
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10
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MISHCHENKO MICHAELI, YURKIN MAXIMA, CAIRNS BRIAN. Scattering of a damped inhomogeneous plane wave by a particle in a weakly absorbing medium. OSA CONTINUUM 2019; 2:2362-2368. [PMID: 33103067 PMCID: PMC7580800 DOI: 10.1364/osac.2.002362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 07/04/2019] [Indexed: 06/11/2023]
Abstract
We use the volume integral equation formulation to consider frequency-domain electromagnetic scattering of a damped inhomogeneous plane wave by a particle immersed in an absorbing medium. We show that if absorption in the host medium is sufficiently weak and the particle size parameter is sufficiently small, then (i) the resulting formalism (including the far-field and radiative-transfer regimes) is largely the same as in the case of a nonabsorbing host medium, and (ii) one can bypass explicit use of sophisticated general solvers of the Maxwell equations applicable to inhomogeneous-wave illumination. These results offer dramatic simplifications for solving the scattering problem in a wide range of practical applications involving absorbing host media.
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Affiliation(s)
| | - MAXIM A. YURKIN
- Voevodsky Institute of Chemical Kinetics and Combustion SB RAS, Institutskaya Str. 3, 630090, Novosibirsk, Russia
- Novosibirsk State University, Pirogova Str. 2, 630090, Novosibirsk, Russia
| | - BRIAN CAIRNS
- NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025, USA
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11
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Mishchenko MI, Dlugach JM. Multiple scattering of polarized light by particles in an absorbing medium. APPLIED OPTICS 2019; 58:4871-4877. [PMID: 31503803 PMCID: PMC6741441 DOI: 10.1364/ao.58.004871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 05/22/2019] [Indexed: 06/10/2023]
Abstract
We study multiple scattering of light by particles embedded in an absorbing host medium using a recently developed single-scattering and vector radiative-transfer methodology directly based on the Maxwell equations. The first-principles results are compared with those rendered by the conventional heuristic approach according to which the single-scattering properties of particles can be computed by assuming that the host medium is nonabsorbing. Our analysis shows that the conventional approach yields very accurate results in the case of aerosol and cloud particles suspended in an absorbing gaseous atmosphere. In the case of air bubbles in water, the traditional approach can cause large relative errors in reflectance, but only when strong absorption in the host medium makes the resulting reflectance very small. The corresponding polarization errors are substantially smaller.
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Affiliation(s)
| | - Janna M. Dlugach
- Main Astronomical Observatory of the National Academy of Sciences of Ukraine, 27 Zabolotny Str., 03143, Kyiv, Ukraine
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12
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Frisvad JR. Phase function of a spherical particle when scattering an inhomogeneous electromagnetic plane wave. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2018; 35:669-680. [PMID: 29603957 DOI: 10.1364/josaa.35.000669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 02/27/2018] [Indexed: 06/08/2023]
Abstract
In absorbing media, electromagnetic plane waves are most often inhomogeneous. Existing solutions for the scattering of an inhomogeneous plane wave by a spherical particle provide no explicit expressions for the scattering components. In addition, current analytical solutions require evaluation of the complex hypergeometric function F12 for every term of a series expansion. In this work, I develop a simpler solution based on associated Legendre functions with argument zero. It is similar to the solution for homogeneous plane waves but with new explicit expressions for the angular dependency of the far-field scattering components, that is, the phase function. I include recurrence formulas for practical evaluation and provide numerical examples to evaluate how well the new expressions match previous work in some limiting cases. The predicted difference in the scattering phase function due to inhomogeneity is not negligible for light entering an absorbing medium at an oblique angle. The presented theory could thus be useful for predicting scattering behavior in dye-based random lasing and in solar cell absorption enhancement.
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13
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Mishchenko MI, Videen G, Yang P. Extinction by a homogeneous spherical particle in an absorbing medium. OPTICS LETTERS 2017; 42:4873-4876. [PMID: 29216132 DOI: 10.1364/ol.42.004873] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 10/20/2017] [Indexed: 06/07/2023]
Abstract
We use a recent computer implementation of the first-principles theory of electromagnetic scattering to compute far-field extinction by a spherical particle embedded in an absorbing unbounded host. Our results show that the suppressing effect of increasing absorption inside the host medium on the ripple structure of the extinction efficiency factor as a function of the size parameter is similar to the well-known effect of increasing absorption inside a particle embedded in a nonabsorbing host. However, the accompanying effects on the interference structure of the extinction efficiency curves are diametrically opposite. As a result, sufficiently large absorption inside the host medium can cause negative particulate extinction. We offer a simple physical explanation of the phenomenon of negative extinction consistent with the interpretation of the interference structure as being the result of interference of the field transmitted by the particle and the diffracted field due to an incomplete wavefront resulting from the blockage of the incident plane wave by the particle's geometrical projection.
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14
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Kok DJ, Guguschev C, Markurt T, Niu M, Bertram R, Albrecht M, Irmscher K. Origin of brown coloration in top-seeded solution grown SrTiO 3crystals. CrystEngComm 2016. [DOI: 10.1039/c6ce00247a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Aernouts B, Watté R, Van Beers R, Delport F, Merchiers M, De Block J, Lammertyn J, Saeys W. Flexible tool for simulating the bulk optical properties of polydisperse spherical particles in an absorbing host: experimental validation. OPTICS EXPRESS 2014; 22:20223-20238. [PMID: 25321232 DOI: 10.1364/oe.22.020223] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this study, a flexible tool to simulate the bulk optical properties of polydisperse spherical particles in an absorbing host medium is described. The generalized Mie solution for Maxwell's equations is consulted to simulate the optical properties for a spherical particle in an absorbing host, while polydispersity of the particle systems is supported by discretization of the provided particle size distributions. The number of intervals is optimized automatically in an efficient iterative procedure. The developed tool is validated by simulating the bulk optical properties for two aqueous nanoparticle systems and an oil-in-water emulsion in the visible and near-infrared wavelength range, taking into account the representative particle sizes and refractive indices. The simulated bulk optical properties matched closely (R2 ≥ 0.899) with those obtained by reference measurements.
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16
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Gaonkar HA, Kumar D, Ramasubramaniam R, Roy A. Decoupling scattering and absorption of turbid samples using a simple empirical relation between coefficients of the Kubelka-Munk and radiative transfer theories. APPLIED OPTICS 2014; 53:2892-2898. [PMID: 24921877 DOI: 10.1364/ao.53.002892] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 03/29/2014] [Indexed: 06/03/2023]
Abstract
Efforts are underway to better understand the absorption properties of micro- and nano-sized particles due to their potential in various photonic applications. However, most of these particles exhibit strong scattering in the spectral regions of interest in addition to absorption. Due to strong interference from scattering, the absorption of these turbid samples cannot be directly measured using conventional spectroscopy techniques. The optical properties of these particles are also different from that of the bulk due to quantum confinement and plasmon resonance effects and cannot be inferred from their bulk properties. By measuring the total transmittance and total reflectance (diffuse and collimated) of turbid samples and using an empirical relation between the coefficients of the Kubelka-Munk and radiative transfer theories, we have demonstrated a method to calculate the absorption and reduced scattering coefficients of turbid samples. This method is capable of extracting the absorption coefficient of turbid samples with an error of 2%. Using this method, we have decoupled the specific absorption and specific reduced scattering coefficients of commercially available micro-sized iron oxide particles. The current method can be used to measure the optical properties of irregularly shaped particle dispersions, which are otherwise difficult to estimate theoretically.
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17
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Wei W, Fedorov AG, Luo Z, Ni M. Radiative properties of dense nanofluids. APPLIED OPTICS 2012; 51:6159-6171. [PMID: 22945164 DOI: 10.1364/ao.51.006159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 07/29/2012] [Indexed: 06/01/2023]
Abstract
The radiative properties of dense nanofluids are investigated. For nanofluids, scattering and absorbing of electromagnetic waves by nanoparticles, as well as light absorption by the matrix/fluid in which the nanoparticles are suspended, should be considered. We compare five models for predicting apparent radiative properties of nanoparticulate media and evaluate their applicability. Using spectral absorption and scattering coefficients predicted by different models, we compute the apparent transmittance of a nanofluid layer, including multiple reflecting interfaces bounding the layer, and compare the model predictions with experimental results from the literature. Finally, we propose a new method to calculate the spectral radiative properties of dense nanofluids that shows quantitatively good agreement with the experimental results.
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Affiliation(s)
- Wei Wei
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, Zhejiang 310027, China
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Dynich RA. Utilization efficiency of spherical metal nanoparticles that increase light absorption in absorbing media. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2011; 28:222-228. [PMID: 21293526 DOI: 10.1364/josaa.28.000222] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This paper proposes a novel approach for estimating the utilization efficiency of metal particles to increase light energy absorption by a medium with a nonzero imaginary part of a medium refractive index. This method is implemented for spherical Ag and Au nanoparticles embedded in muscle tissue. Numerical calculations for spheres in absorbing media show that the utilization efficiency of metal particles increases with the decreasing absorbability of the medium.
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Affiliation(s)
- Raman A Dynich
- BI Stepanov Institute of Physics, National Academy of Sciences of Belarus, 68 Prospekt Nezavisimosti, Minsk BY-220072, Belarus.
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