• 제목/요약/키워드: point-diffraction interferometer

검색결과 14건 처리시간 0.016초

Volumetric Interferometry Using Spherical Wave Interference for Three-dimensional Coordinate Metrology

  • Rhee, Hyug-Gyo;Chu, Ji-Young;Kim, Seung-Woo
    • Journal of the Optical Society of Korea
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    • 제5권4호
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    • pp.140-145
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    • 2001
  • We present a new method of volumetric interferometer, which is intended to measure the three-dimensional coordinates of a moving object in a simultaneous way with a single optical setup. The method is based on the principles of phase-measuring interferometry with phase shifting. Two diffraction point sources, which are made of the polished ends of single-mode optical fibers are embedded on the object. Two spherical wavefronts emanate from the diffraction point sources and interfere with each other within the measurement volume. One wavefront is phase-shifted by elongating the corresponding fiber using a PZT extender. A CCD array sensor fixed at the stationary measurement station detects the resulting interference field. The measured phases are then related to the three-dimensional location of the object with a set of non-liner equations of Euclidean distance, from which the complete set of three-dimensional spatial coordinates of the object is determined through rigorous numerical computation based upon the least square error minimization.

Shack-Hartmann 파면분석기와 점광원을 이용한 광학부품의 수차 측정 (Wavefront Aberration Measurement with Shack-Hartmann Sensor and Point Source)

  • 이진석;김학영;박영필;박노철;한재원
    • 정보저장시스템학회:학술대회논문집
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    • 정보저장시스템학회 2005년도 추계학술대회 논문집
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    • pp.160-161
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    • 2005
  • Using a Shack-Hartmann sensor, we construct an optical testing system measuring the wavefront error of small optical components. The systematic error of the sensor is compensated with a reference plane-wave system that produces almost perfect plane waves. Several types of lenses are tested using a point source that generates spherical waves emitted from a pinhole. The results of the optical testing obtained with the Shack- Hartman sensor are compared with those measured with Zygo interferometer.

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위상천이 디지털 홀로그래피를 이용한 3차원 상대 거리 측정 (Three-dimensional relative-distance measurement by use of the phase-shifting digital holography)

  • 김현;이연호
    • 한국광학회지
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    • 제14권2호
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    • pp.200-207
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    • 2003
  • 본 논문에서는 기존의 위상천이 디지털 홀로그래피에서 기준빔으로 사용되는 평면파 대신 보다 일반적인 구면파를 이용하여 3차원 공간상에 위치한 두 물체점들 사이의 상대적인 거리를 측정하는 새로운 시스템 및 알고리듬을 제안한다. 본 논문에서는 이러한 시스템에 대한 모의실험 및 광학실험을 실시하였다. 이러한 시스템에서는 홀로그램 기록에 사용된 기준빔의 정확한 정보를 알고 있지 않더라도 3차원 공간상의 두 물체점들 사이의 상대적인 거리를 정확하게 측정할 수 있다. 본 논문에서는 광학실험을 통하여 약 300 cm 거리에서 서로 0.5 cm 떨어진 두 물체점들 사이의 상대적인 거리를 10% 미만의 오차로 측정하였다.

삼각형 간섭계를 이용한 Incoherent 홀로그래피의 수치적 재생에 관한 연구 (Numerical reconstruction of Incoherent Holography using the triangular interferometer)

  • 배유석;이혁
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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    • pp.388-390
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    • 1994
  • We are familiar with the holography in these days. For making holography the coherent sources like LASER are used in many fields. But coherent holography has many problems. Coherent holography needs many instrument for practical use like 3-D TV case. In solving the problem we use the non-coherent source. Nowadays many methods like conoscopic holo graphy using anisotropic crystal, shadow casting and interferometric systems are suggested. In this paper we make the hologram using the triangular interferometric systems. [1],[2],[3],[4]. We explain the afocal and double-afocal system which consists of the triangular interferometric system. The holography made in one point and two point cases is imaged on CCD camera and we handle the image data digitally for the reconstruction efficiently. In reconstructing the hologram the Fraunhofer diffraction theory is used. We adopt the rectangular aperture for the convenience of calculation. In the future we must reconstruct the perfect 3-Dimensional object by optical method. For this, we have many problems like resolution problem. We must solve these problem for perfect reconstruction.

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