• Title/Summary/Keyword: Light-scattering model

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Mumerical Anlysis of light Scattering Patterns for Measurement of Roughmess(I) (표면 거칠기 광산란 패턴의 컴퓨터 수치 분석 (I))

  • 임동열;김승우
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.2
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    • pp.267-280
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    • 1992
  • This paper describes a numerical analysis of the light scattering patterns of roughness profiles. This analysis was based upon the light scattering theory developed by Beckmann. In the analysis, the roughness profile was regarded as a profile whose irregularities depend on the production process and the shape of cutting tool. Generally, waviness of an actual surface seriously distorts the scattered pattern of roughness profile. In order to avoid the effects of waviness of actual surfaces, several theoretically calculated scattering patterns, instead of actual scattering patterns, were used to analyze the scattering patterns of typical engineering roughness profiles. The characteristics of the light scattering patterns for five model surfaces were studied.

Improving the Performances of Dye-Sensitized Solar Cell by the Optimal $TiO_2$ Photoelectrode Thickness and Light-Scattering Enhancement (최적 $TiO_2$ 전극 두께 및 광산란 증가에 의한 염료감응형 태양광전지의 효율 개선)

  • Niu, Zeng Yuan;Kweon, Hyun Kyu;Park, Chang Yong
    • Journal of the Semiconductor & Display Technology
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    • v.13 no.2
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    • pp.37-44
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    • 2014
  • In this study, the performance of dye-sensitized solar cells with different thickness of the photelectrode film was simulated by using the electron-diffusion differential model. Through this simulation, the relationships between the thickness of the photoelectrode film and the performances (open-circuit voltage, short-circuit current density, and overall photoelectric-conversion efficiency) of cells were understood and the performances with different thickness of the photoelectrede film were also examined. For considering the refractive index in the liquid electrolyte and exploring the scattering effect of titanium dioxide particles with different sizes using the Mie light-scattering theory, the highest scattering effect of each particles was found out and the optimal size of the titanium dioxide particle was determined for light scattering in the photoelectrode film of dye-sensitized solar cell. Through experiment, the mixed titanium dioxide cell was better than the single titanium dioxide cell and generated a higher overall conversion efficiency because the optimal titanium dioxide particles in the phoelectrode film as light scattering.

A Gaussian Beam Light Distribution Model of the Biological Tissue (생체의 가우스빔 광분포모델)

  • 조진호;하영호;이건일
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.6
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    • pp.654-662
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    • 1988
  • A simple and useful model of light distribution for the biologhical tissue to the Gaussian beam is proposed. This model assumes that the incident Gaussian beam broadens into two Gaussian beams, travelling in the opposite directions as the result of both isotropic scattering and absorption in the tissue. With this assumption, two-dimensional light intensity of each flux as well as the equations of both absorption and scattering have been derived, and the validity of modeling has been confirmed experimentally. Consequently, the results paved a way for easy evaluation of the light distribution in the biological tissue.

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Study on Analysis of Optical Deflection of Laser Scattering Based on Rayleigh Criterion for Crystalline Silicon Wafer in Solar Cell (태양전지용 결정질 실리콘 웨이퍼에서의 레일리기준 기반 레이저산란의 광편향 분석에 관한 연구)

  • Kim, Gyung-Bum
    • Journal of the Semiconductor & Display Technology
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    • v.9 no.4
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    • pp.31-37
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    • 2010
  • In this paper, optical deflection of laser scattering has been investigated based on Rayleigh criterion for crystalline silicon wafer in solar cell. A laser scattering mechanism is newly designed using light scattering properties in silicon wafer. Intensity distributions of laser scattering are different, depending on the incident angle of laser computed from Rayleigh criterion. In case of the incident angle satisfied with the criterion, they are asymmetric. Also, their specular reflection angle is shifted to unpredicted ones. These phenomena are in accordance with previous theories of laser scattering. The optical deflection of laser scattering is experimentally identified with the designed laser scattering mechanism. Its mathematical model is presented from the geometric relationship of laser scattering. It is shown that the optical deflection of laser scattering agree with the presented model, exclusive of grazing angles which is satisfied with Rayleigh criterion.

Verification on Diffusion of Beam Propagation in Randomly Distributed Scattering Medium (무질서하게 분포된 산란매질에서 빔전파의 확산에 관한 검증)

  • Kim, Ki-Jun;Lee, Hoo-Seol
    • Journal of the Korean Applied Science and Technology
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    • v.24 no.4
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    • pp.354-361
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    • 2007
  • The distribution of light in a randomly scattering medium can represent problems found in many area. Particularly, in the clinical application of lasers for Photodynamic therapy(PDT) or in the fluorescence spectroscopy for biological tissue, turbidity plays a very important role. The influences of fluorophor, scatterer, and absorber in turbid material by light scattering were interpreted for the scattered fluorescence intensity and wavelength. The molecular properties have been studied by laser induced fluorescence spectroscopy in scattering medium as tissue. It has been found that the effects of optical properties in scattering media could be investigated by the optical $parameters({\mu}_s$, ${\mu}_a$ ,${\mu}t)$. Experimental and Monte Carlo simulation method for modelling light transport in tissue was applied. The experimental results using a randomly distributed scattering medium were discussed and compared with those obtained through Monte Carlo simulation. It'll be also important in designing the best model for oil chemistry, medicine and application of medical engineering.

Penetration depth and Wave Propagation in Random Media (무질서한 매질에서 침투깊이와 파동 전파)

  • Kim, Ki-Jun;Sung, Ki-Chun
    • Journal of the Korean Applied Science and Technology
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    • v.23 no.1
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    • pp.70-76
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    • 2006
  • The influence of fluorophor, scatterer, absorber in turbid materials by light scattering were interpreted for the scattered fluorescence intensity and wavelength, it is studied the molecular property by laser induced fluorescence spectroscopy. It can be found that the effects of optical property are penentrated in scattering media by the optical $parameters({\mu}s$, ${\mu}a$, ${\mu}t$, ${\gamma}$, ${\rho})$. The value of scattering coefficient ${\mu}s$ is large appeared by means of the increasing particles of scattering, it can be found that the slope appears exponentially as a function of distance from laser source to detector. It may also utilize in designing the best model for oil chemistry, laser medicine and application of medical engineering.

Measurement and Analysis of Light Scattering of Au Pads on PCB Surface to Extract Scattering Parameters (인쇄회로기판용 Au 패드의 산란 특성 측정 및 분석에 의한 산란 인자 추출)

  • Ko, Nak-Hoon;Park, Dae-Seo;Kim, Young-Seok;O, Beom-Hoan;Park, Se-Geun;Lee, El-Hang;Lee, Seung-Gol;Choi, Tae-Il
    • Korean Journal of Optics and Photonics
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    • v.20 no.2
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    • pp.134-140
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    • 2009
  • In this study, the influence of surface roughness on light scattering from Au pads on a PCB surface was investigated. Angular distributions of light scattered from Au pads with different surface roughness were measured for several incident angles. Diffusely-scattered light could be separated by using the fact that the amount of specularly-scattered light was directly related to surface roughness. The separated diffuse term was curve-fitted with a physics-based model, and then the related scattering parameters were extracted and compared with measured parameters.

Prediction of Color Reproduction using the Scattering and Absorption Coefficients derived from the Kubelka-Munk model in Package Printing (패키지 인쇄에 있어서 Kubelka-Munk Model 유래의 산란 및 흡수 계수를 이용한 색상 재현성 예측)

  • Hyun, Young-joo;Park, Jae-sang;Tae, Hyun-chul
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.27 no.3
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    • pp.203-210
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    • 2021
  • With the development of package printing technology, the package has expanded from the basic function of protecting products to the marketing function through package design. Color, the visual element that composes the package design, is delivered to the consumer most quickly and effectively. As color marketing of these package designs expands, accurate color reproduction that the product wants to express is becoming more important. The color of an object is transmitted by absorption and scattering of light. Spectral reflectance refers to the intensity of light reflected by an object at different wavelengths by the spectral effect. As a result, the color of the object is expressed in various colors. Packaged printing inks have their own absorption and scattering coefficients, and the Kubelka-Munk model for color reproduction and prediction defines the relationship between these correlation coefficients through reflectance. In the Kubelka-Munk model for color reproduction and prediction, the relationship between the absorption and scattering coefficients (K/S) of printed material is predicted as the sum of the K/S values according to the mixing ratio of all color ink used. In this study, the reflectance of the measured print is reversely calculated at the mixing ratio of print ink using the Kubelka-Munk model. Through this, the relationship value of the ink-specific absorption/scattering coefficient constituting the final printed material is predicted. Delta E is derived through the predicted reflectance, and the similarity between the measured value and the predicted value is confirmed.

LABORATORY SIMULATION OF LIGHT SCATTERING FROM REGOLITH ANALOGUES: EFFECT OF POROSITY

  • KAR, AMRITAKSHA;DEB, SANJIB;SEN, A.K.;GUPTA, RANJAN
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.65-67
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    • 2015
  • The surfaces of most atmosphereless solar system objects are referred to as regolith, layers of loosely connected fragmentary debris, produced by meteorite impacts. Measurements of light scattered from such surfaces provides information about the composition and structure of the surface. A suitable way to characterize the scattering properties is to consider how the intensity and polarization of scattered light depends on the particle size, composition, porosity, roughness, wavelength of incident light and the geometry of observation. In the present work, the effect of porosity on bidirectional reflectance as a function of phase angle is studied for alumina powder with grain size of $0.3{\mu}m$ and olivine powder with grain size of $49{\mu}m$ at 543.5 nm. The optical constants of the alumina sample for each porosity were calculated with Maxwell Garnett effective medium theory. On using each of the optical constants of alumina sample in Mie theory with the Hapke model the variation of bidirectional reflectance is obtained as a function of phase angle with porosity as a parameter. Experimental reflectance data are in good agreement the model. For the olivine sample the effect of porosity is studied using Hapke (2008).

Studies on the Measurements of Optical Parameters in Turbid Material by Light Scattering (혼탁 매질에서 광산란에 의한 광학적 파라미터들의 측정에 관한 연구)

  • Kim, Ki-Jun;Sung, Ki-Chun
    • Journal of the Korean Applied Science and Technology
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    • v.12 no.2
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    • pp.151-156
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    • 1995
  • The influences of fluorophor, scatterer, absorber in turbid material by light scattering were interpreted for the scattered fluorescence intensity and wavelength, it has been studied the molecular properties by laser induced fluorescence spectroscopy. It has been found that the effects of optical properties in scattering media by the optical parameters(${\mu}_{s}$, ${\mu}_{a}$, ${\mu}_{t}$). The value of scattering coefficient ${\mu}_{s}$ is large by means of the increasing particles of scatterer, it has been found that the slope decays exponentially as a function of distance from laser source to detector. It may also aid in designing the best model for oil chemistry, laser medicine and application of medical engineering.