• Title/Summary/Keyword: optical scattering

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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.

General Theory of Wave Scattering by Two Separated Particles

  • Park, Byong Chon;Kim, Myung-Whun;Kim, Jin Seung
    • Journal of the Optical Society of Korea
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    • v.18 no.2
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    • pp.188-193
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    • 2014
  • A general theory of scalar wave scattering by two separated particles is developed to give the coefficients of scattering and transmission in the form of recurrence formulae. Iterative applications of the formulae yield the coefficients in the form of power series of the coefficients obtained from single-particle scattering theories, and each term of the of power series can be interpreted as multiple scattering of the wave between the two particles in increasingly higher order.

A study on the LCD backlight unit using polymer (LCD backlight unit의 고분자 산란형 도광판에 관한 연구)

  • 정일용;박우상
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.578-581
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    • 1999
  • Dot pattern print methods composed of a diffusion film and two prism sheets, have been generally used for backlighting systems of LCDs. However, this methods require complex structures and show high power consumption and optical loss. To improve these disadvantages of conventional backlight units, light guides using highly scattering optical transmissions (HSOT) polymer as scatters, have been introduced. In this study we analyzed multiple scattering effect in light guide by means of Monte carlo simulation based on Mie scattering theory and ray tracing method. As a result it was revealed that scattering intensity depends on the size of scatters. On the other hands, it was shown that scattering efficiency depends on the wavelength of fluorescent lamp as well as the size of scatters.

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Measurements of Optical Constants of Biomedical Media Based on Time-Resolved Reflectance (시간 분해 반사율 측정에 의한 다중산란 매질의 광학 계수 측정)

  • Jeon, K.J.;Park, S.H.;Kim, U.;Yoon, K.W.;Kim, W.K.
    • Proceedings of the KOSOMBE Conference
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    • v.1996 no.05
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    • pp.235-239
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    • 1996
  • In recent years, the optical properties of multiple-scattering media like tissue have been studied for their potential applications in medicine. In this work the optical properties of multiple scattering media were investigated using the time-resolved reflectance measurement. The reflected light was measured by time-correlated single photon counting system. The transport scattering and absorption coefficient are related to the initial rapid decay and the subsequent decay in reflected light, respectively. Also the optical properties of the samples were measured by conventional method, ie., using continuous wave light. When the distance between the light source and the detector is over 8mm, the optical coefficient can be measured accurately using the suggested method.

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Suppression of Stimulated Brillouin Scattering in Optical Fiber using Sampled-Fiber Brags Grating (샘플링 광섬유 Bragg 격자를 이용한 광섬유 내의 유도 Brillouin 산란 억제)

  • Lee, Ho-Joon
    • Korean Journal of Optics and Photonics
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    • v.16 no.6
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    • pp.485-489
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    • 2005
  • I have investigated a scheme for suppressing stimulated Brillouin scattering in optical fibers. The scheme makes use of a sampled Bragg grating fabricated within the fiber used for transmitting intense Q-switched pulses. The grating is designed such that the spectrum of the Stokes pulse generated through stimulated Brillouin scattering falls entirely within its stop band. I show numerically that the number of sampled fiber Bragg gratings in 1 m is applied directly to suppressing stimulated Brillouin scattering rather than the coupling coefficient. This prevents the build up of the backward-propagating Stokes wave and mitigates the deleterious effects of stimulated Brillouin scattering. The simulation shows that 15 ns pulses with 1 kW peak power can be transmitted though a 1 m-long fiber with little energy loss using this scheme.

Position Detection of a Scattering 3D Object by Use of the Axially Distributed Image Sensing Technique

  • Cho, Myungjin;Shin, Donghak;Lee, Joon-Jae
    • Journal of the Optical Society of Korea
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    • v.18 no.4
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    • pp.414-418
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    • 2014
  • In this paper, we present a method to detect the position of a 3D object in scattering media by using the axially distributed sensing (ADS) method. Due to the scattering noise of the elemental images recorded by the ADS method, we apply a statistical image processing algorithm where the scattering elemental images are converted into scatter-reduced ones. With the scatter-reduced elemental images, we reconstruct the 3D images using the digital reconstruction algorithm based on ray back-projection. The reconstructed images are used for the position detection of a 3D object in the scattering medium. We perform the preliminary experiments and present experimental results.

A noncontact optical roughness measurement technique of ground surface by light scattering (광산란을 이용한 연삭표면의 비접촉식 광학적 조도측정기술)

  • 임동열;김승우
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.6
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    • pp.1303-1311
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    • 1988
  • Described is method for development of an optical roughness measurement sensor for in-subequality assurance in the precision grinding. Main approach is made based upon the Brckmann's light scattering theory, in which general solutions of the optical scattering behaviour are given under many simplifying assumptions on the model of the surfaces illuminated. For the ground surface, the assumptions are verified through computer simulation and experimental work in order to examine the validity of Beckmann's theory on predicting the optical responses according to the roughness variation. As a result, an optical monitoring strategy is derived which can evaluate the roughness value of the ground surface by statistically detecting the pattern of intensity distribution of the scattered light. Finally, the strategy is proven by comparing with the results using the stylus method.

Optical Clearing Agent Decreases Scattering of Stratum Corneum and Modulates Physical Properties of Corneocytes by Hydration (광산란 감소 물질에 의한 피부 각질층의 산란 감소 및 수화에 의한 각질세포의 물리적 특성에 대한 연구)

  • Jun, Seung-Hyun;Yeom, Jun-Seok;Ahn, Byung Jun;Park, Sun Gyoo;Lee, Cheon Koo;Lee, Seol-Hoon;Kang, Nae-Gyu
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.44 no.1
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    • pp.81-87
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    • 2018
  • The objective of this article is to provide analytical tools for the scattering of stratum corneum (SC) and to check whether the optical clearing agents (OCAs) could be applied in optics affecting the scattering reduction. Dark field images of tape striped corneocyte separates scattered light of the SC from others in vitro. Several optical clearing agents were tested to reduce the scattering. Physical properties of SC such as water contents, keratin configuration and volume after OCAs treatment were investigated by FT-IR and 3D laser microscope. Several reducing sugars, monomeric sugars, sugar alcohol, and hyaluronic acid, which were used as humectants in cosmetic field, also reduced scattering. However, unlike dehydration in optics, water penetrated into the keratin in SC and scattering was decreased at low concentration of OCAs. In that condition, the volume of corneocyte was increased and stiffness seemed to decrease. The analyzing of tape-stripped SC, showed the change of optical and physical properties of corneocyte by optical clearing agents. The hydration of SC layer by optical clearing agents decreased the scattering of corneocyte and thus improved the skin appearance and moisturizing effect, which are important benefits in the cosmetic field and could provide new possibility to develop skin care study targeting at SC.

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.