• 제목/요약/키워드: Scattered Light

검색결과 247건 처리시간 0.024초

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

  • 김기준;성기천
    • 한국응용과학기술학회지
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    • 제23권1호
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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.

PHASE VARIATION IN DOPPLER SIGNAL FOR VARIOUS OPTICAL PARAMETERS

  • Son, Jung-Young;Kim, Myung-Sik;Oh, Myung-Kwan
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1989년도 하계종합학술대회 논문집
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    • pp.629-632
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    • 1989
  • The scattered light intensity from a spherical particle passing through the cross-over region of two coherent laser beams, varies periodically. Photodetection of this light beams produces a periodic signal of varying amplitude. The phase of the signal varies with the particle size and refractive index, the beam crossing angle and wavelength, and the position and size of the scattered ligth collecting aperture. In this paper the phase variation with respect to the particle absorptive index of retraction, collecting lens size and beam crossing angle is calculated using both Mie scattering theory and reflection theory. The two theories show good agreement in phase predictions, especially for large absorptive indices and for small collection lenses. Both theories predict phase to be inversely proportional to the beam crossing angle.

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레이저빔 반사 화상을 이용한 연마면 거칠기 측정법에 관한 연구 (A Study on Roughness Measurement of Polished Surfaces Using Reflected Laser Beam Image)

  • ;임한석;김화영;안중환
    • 한국정밀공학회지
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    • 제16권2호통권95호
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    • pp.145-152
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    • 1999
  • This paper presents the principle and experimental results of a non-contact surface roughness measurement by means of screen projected pattern of lase beam reflected from a polished surface. In the reflected laser beam pattern especially from a fine surface like ground or polished one, light intensity varies from the center fo the image to its boundary as the Gaussian distribution. The standard deviation of a light intensity distribution is assumed to be a good non-contact estimator for measuring the surface roughnes, because the light reflectivity is known to be well related with the surface roughness. This method doesn't need to discriminate between the specularly reflected light and the diffusely reflected one, whereas the scattered laser intensity method must do. Nor it needs to adjust the change of light intensity caused by environmental lights or specimen materials. Reflected laser beam pattern narrowly spreads out in the vertical direction to tiny scratches on the polished surface due to abrasives. The deeper the scratch the more the dispersion, which means the rougher surface. The standard deviation of the pattern is nearly in proportion to the surface roughness. Measurement errors by this method are shown to be below 10 percent compared with those obtained by a common contact method. The inclination of measuring unit from the normal axis causes the measurement errors up to 10 percent for an angle of 4 degree. Therefore the proposed method can be used as an on-the-machine quick roughness estimator within 10 percent measurement error.

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Improvement of output coupling efficiency of organic light emitting device by using porous anodic alumina

  • Lee, Hyung-Sup;Choi, Ji-Young;Gao, Xinwei;Kim, Seong-Su;Lee, K.W.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.625-628
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    • 2004
  • Porous anodic alumina(PAA) which has arrays of nano size holes, was incorporated into organic light emitting devices. Porous anodic alumina on glass scattered the light generated from emitting layer and was decreased the waveguiding modes within the glass. An increase in the device coupling-out factor for the scattering structure is demonstrated.

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산란이론과 신경회로에 의한 입자크기계측 (Particle Sizing Using Light Scattering and Neural Networks)

  • 남부희;이상재;박민현;이영진;이석원;류태우;방병렬
    • 제어로봇시스템학회논문지
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    • 제6권6호
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    • pp.447-453
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    • 2000
  • Using the scattering theory of laser light, we analyze the particle sizing method. The scattered profile measured by the photodetector is sampled, scale conditioned by a 32 channel analog-to-digital converter, and is analyzed with the transform matrix from the light energy signals to the weights of the particle sizes. The particle size distribution is classified using the Hopfield neural network method as well as the conventional nonnegative least square method.

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Effect of Wavelength-dependent Scattering on the Color Chromaticity of the LCD Backlight

  • Kwon, Jin Hyuk;Jun, Hwa Joon;Gwag, Jin Seog;Lee, Hong Su
    • Journal of the Optical Society of Korea
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    • 제17권3호
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    • pp.275-278
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    • 2013
  • The effect of the wavelength-dependent scattering on the change of the color chromaticity in the lightguide panel of a liquid crystal display is examined. The white light emitted from the white LEDs located at the edge of the lightguide propagates in the lightguide and is scattered by the patterned dots that are placed on the bottom of the lightguide. The scattered lights that are far from the LEDs showed reddish color compared to the bluish color that is scattered from the near area from the LEDs. The color difference was between 0.01 to 0.06 depending on the resin and the thickness of the lightguide.

In Vitro에서 광증감제에 의한 광학적 영향에 관한 연구 (A Study on the Optical Influence by Photosensitizer in Vitro)

  • 김기준;성기천
    • 한국응용과학기술학회지
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    • 제22권2호
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    • pp.182-190
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    • 2005
  • The propagation of light radiation within tissues is an important problem that confronts the dosimetry of therapeutic laser delivery and the development of diagnostic spectroscopy. In the clinical application of photodynamic therapy(PDT) and in photobiology, the photon deposition within a tissue determines the spatial distribution of photochemical reactions. Scattered light is measured as a function of the distance (r) between the axis of the incident beam and the detection spot. Consequently, knowledge of the photosensitizer(Chlorophyll-a) function that characterizes a phantom is important. To obtain the results of scattering coefficients(${\mu}s$) of a turbid material from diffusion described by experimental approach. It was measured the energy fluency of photon radiation at the position of penetration depth. From fluorescence experimental method obtained the analytical expression for the scattered light as the values of $(I\;/I_o)_{wavelength}$ vs the distance between the center of the incident beam and optical fiber in terms of the condition of "in situ spectroscopy(optically thick)" and real time by fluorometric measurements.

세포내 염색체의 분산에 관한 연구 -적혈염용액의 광조사 처리에 의한 염색체의 분산- (The Study on Scattering of Chromosomes in Cells -Scattering of Chromsomes by Treatment with Potassium Ferricyanide Solution under Light-)

  • 김종호
    • Journal of Plant Biology
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    • 제17권3호
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    • pp.113-117
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    • 1974
  • In counting chromosome number and karyotype study, it is necessary to let chromosomes on metaphase by pretreatment before fixation. For this purpose, colchicine, or 8-oxyquinoline are generally used. The author found out that chromosomes could be scattered by illuminating cyanoferrate complex solution in which root-tips were sunk. As materials, 8 sorts of plant such as Allium fisturosum, allium tuberosum Rottler, Triticum vulgare were used. Their root-tips were sunk on the bottom of beaker in potassium ferricyanide solution $3{\times}10-4M$ and illuminated through the solution by sterilizing lamp for 1~2 hours in dark room, keeping 10 cm distance from light source to the surface of solution and 2cm depth of solution. Then again, they were illuminated to the light which was somewhat weaker intensity than the former (distance, 16cm; depth, 3cm) for 1.5~2 hours after immersed in 1/100N-HCl and washed in water for each 5minutes. By such methods chromosomes could be scattered. About the mechanism of scattering, it is supposed that CN and Fe(CN)x ions $(x {\leq}5)$ which were gradually produced in the process of photodissociation acted together on the scattering of chromosomes.

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도로조명의 빛공해 계산 및 규제안 제안 (Calculation and Regulation Proposal of Light Pollution from Road Lightings)

  • 조숙현;이민욱;최현석;김훈
    • 조명전기설비학회논문지
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    • 제25권12호
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    • pp.21-26
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    • 2011
  • This is a study to establish regulations against light pollution for lighting on roads. Many kinds of light pollution by luminaire on roads was calculated and analyzed by applying the classification method of luminaires(Cut-off classification of IDA-IESNA, BUG Rating Classification) and the calculation method of Upward Lighting Ratio of CIE among measures to prevent light pollution that international lighting organizations suggest. As a result of the analysis, it was found that the regulation by Cutoff of IESNA and ULR classification of CIE could be one for scattered light of light pollution compared to BUG classification but is not sufficient for the regulation of light tresspass or glare. BUG classification by each lighting zone was suggested as threshold value of the light pollution regulation considering domestic conditions.