• Title, Summary, Keyword: 레이저 산란

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Study on the Experimental Identification of Surface Roughness Using Laser Scattering Image (레이저 산란 영상을 이용한 표면거칠기의 실험적 규명에 관한 연구)

  • Hong, Yeon-Ki;Kim, Gyung-Bum
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.1
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    • pp.35-41
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    • 2010
  • In this paper, surface roughness has been experimentally identified using laser scattering images. The parameters and optical deflected rays of laser scattering are investigated on laser scattering system, and then their optimum parameters on grinding surfaces are selected using design of experiment. The application of the optimum parameters results in featured laser scattering images, in which the mean of vertical scattering distributions is regarded as a feature. It is shown that the feature of laser scattering distributions is linearly increased according to grinding surface roughness and so the information can be used as important factor for the measurement and evaluation of various surface roughness. In the future, the performance of the proposed laser scattering method will be evaluated using AFM.

Study on Experimental Modeling and Estimation of Roughness of Nanoscale Lapping Surface Based on Laser Scattering Patterns (레이저산란패턴 기반 나노 래핑 표면 거칠기의 실험적 모델링 및 추정에 관한 연구)

  • Hong, Yeon-Ki;Kim, Gyung-Bum
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.1
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    • pp.107-114
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    • 2011
  • In this study, a correlation between the roughness of nanoscale lapping surface and its laser scattering pattern has been identified experimentally. The characteristics of laser scattering on a reflected surface are investigated, and a laser scattering mechanism is newly designed by adopting the dark-field method. Laser scattering patterns resulting from nanoscale lapping shape are in the shape of crossed irregular lattice. In addition, optimum laser scattering images are obtained by the design of experiment, and the roughness of nanoscale lapping surface is estimated using regression analysis certain useful features of the laser scattering patterns. The results of fifty experiments on three types of nanoscale lapping surfaces show that the roughness of nanoscale lapping surfaces can be accurately estimated by the proposed mathematical modeling method.

Measurement of angular velocity using the self-mixing effect of semiconductor laser (되먹임 효과를 이용한 회전체의 속도측정)

  • 이병욱
    • Korean Journal of Optics and Photonics
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    • v.11 no.4
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    • pp.250-254
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    • 2000
  • We have constructed laser Doppler velocimetry system using self-mixing effect with a semiconductor laser. This technology is based on the frequency mixing phenomena which occurs when light scattered back from the moving object into the laser cavity interferes with light inside the laser. We have compared the value of Doppler shifted frequency with the velocity variation of the wheel. Frequency dependence on the angle between the moving direction of rotating aluminum wheel and the incident beam also have been proved. As an illustration of the performance of the velocimeter, velocity measurements of a rotating disk are described. Doppler signal shows a good linear relationship with velocity of rotating disk.

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The Turbidity Measured by Division Image Analysis in Flow Type Sample (분할화상분석에 의한 흐름 형태 시료의 탁도 측정)

  • Park, Jong-Ho;Park, Soo-Haeng;Ryu, Min-Su
    • Applied Chemistry for Engineering
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    • v.20 no.6
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    • pp.681-684
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    • 2009
  • The turbidity of flow type samples has a nonlinear relation to brightness of laser scattered light, but the shape of images in laser scattered light is different from each turbidity samples. The turbidity measurement will be easy if it uses a pattern of images in laser scattered light. But the excessive analysis load comes from the turbidity measured by red, green, blue intensity (intensity) of all pixels of images in laser scattered light. Therefore the images in laser scattered light were divided by appropriate block to decrease excessive analysis load. The shape of divided images in laser scattered light was different from each turbidity sample. The real turbidity has a linear relation to turbidity measured by the artificial neural network learned with the intensity of divided images in laser scattered light and turbidity.

레이저 기반 플라즈마 진단

  • Seo, Byeong-Hun;Kim, Jeong-Hyeong;Seong, Dae-Jin;Yu, Sin-Jae
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.94.1-94.1
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    • 2016
  • 레이저 진단은 플라즈마 진단법 중 가정 정확한 진단법으로 알려져 있다. 특히 진단이 까다로운 고밀도, 자기장, 고압 환경에서도 그 측정 결과가 신뢰성 있다고 잘 알려져 있다. 본 특별 심포지엄에서는 중 성종을 측정 할 수 있는 레일레이 산란과 자유 전자를 측정 할 수 있는 톰슨 산란, 그리고 분자를 측정할 수 있는 라만 산란을 중심으로 발표 할 것이다. 또한 특정 준위를 갖는 원자 및 분자의 거동을 측정할 수 있는 레이저 유도 형광에 대해서도 간단히 발표 할 것이다. 그밖에 레이저 진단의 종류, 원리 등을 설명 하고 한국표준과학연구원에서 이루어 진고 있는 연구 결과에 대해 발표 할 것이다.

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Laser doppler velocimeter using the self-mixing effect of a $CO_2$ laser (산란광의 되먹임을 이용한 $CO_2$ 레이저 도플러 속도 측정)

  • 최종운;김용평;김윤명
    • Korean Journal of Optics and Photonics
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    • v.7 no.2
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    • pp.157-161
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    • 1996
  • A simple laser Doppler velocimeter(LDV) using a $CO_2$ laser with its self-mixing effect has been developed. We measured the laser power which was modulated by Doppler frequency, when monochromatic laser light was focused to a moving target. The Doppler-shifted frequency was controlled by changing rotating speed of the turntable or the cosine of the angle between the direction of the laser beam and that of the rotating velocity.

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Fabrication of PDMS microlens for optical detection (광학적 검출을 위한 PDMS 마이크로렌즈의 제작)

  • Park, Se-Wan;Kim, Hyeon-Cheol;Chun, Kuk-Jin
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.46 no.4
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    • pp.15-20
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    • 2009
  • In a detection system based on laser light scattering, focusing an excitation laser beam into a focal point of a channel in a microfluidic chip is important for obtaining the highest excitation intensity, and consequently for obtaining a laser light scattering signal using a photodetector with a high efficiency. In this paper, we present a polydimethylsiloxane (PDMS) microfluidic chip consisting of an integrated PDMS microlens for cell detection based on laser light scattering. We fabricated PDMS microlens for optical detection system by simply putting down on PDMS chips. The PDMS microlens was fabricated by photoresist reflow and replica molding. This fabrication technique is simple and has an excellent property in terms of the microlens and a high-dimensional accuracy. The PDMS microlens integrated on the PDMS microfluidic chip has been verified to improve the laser intensity, and accordingly, the signal-to-noise ratio and sensitivity of laser light scattering detection for red blood cells(RBCs)

Laser doppler velocimetry using the optogalvanic effect of $Co_2$ laser (광전류 효과를 이용한 $Co_2$ 레이저 도플러 속도 측정기)

  • 최종운;김용평;김윤명
    • Korean Journal of Optics and Photonics
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    • v.8 no.6
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    • pp.482-485
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    • 1997
  • A new laser Doppler velocimeter employing a $CO_2$laser has been developed by using its optogalvanic effect. A change in the electric impedance of a discharge, induced by mixing of a returned wave with an originally existing wave inside the cavity, was employed to detect the Doppler frequency shift. A Doppler frequency shift as much as 60 KHz was detected, and also a good linear relationship between the velocity and the Doppler frequency shift was obtained.

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Response of laser light active scattering aerosol spectrometer to light-absorbing aerosol particulates (광흡수성 분체입자에 대한 레이저산란광 분체입도측정기의 반응 특성)

  • Jeung, I. S.
    • Journal of the korean Society of Automotive Engineers
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    • v.6 no.2
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    • pp.55-63
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    • 1984
  • Berglund-Liu 진동방식 단분산 분체입자 발생기(Berglund-Liu vibrating orifice monodisperse aerosol generator)에 의하여 제작한 단분산 광흡수성 표준분체입자를 사용하여 레이저 산란광 분체입도 측정기 (Knollenberg active scattering aerosol spectrometer)의 반응특성을 조사하 였다. 실험결과, 기기의 반응특성은 Mie 산란이론에 의하여 계산한 이론치와 매우 잘 일치하며 특히 광흡수성 분체입자는 광통과성 분체입자가 다의적인 특성을 나타내는 것에 반하여 거의 단조증가하는 일의적인 특성을 가지고 있으며 광흡수성 분체입자의 반응특성이 제작자의 교정 치에 가까운 결과를 나타내었다.

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