• Proceedings of the Optical Society of Korea Conference
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• 2008.07a
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• pp.271-272
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• 2008

• Proceedings of the Optical Society of Korea Conference
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• 2008.07a
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• pp.287-288
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• 2008

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.131-132
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• 2006

• Ceramist
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• v.7 no.3
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• pp.10-14
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• 2004

최근 광 네트워크 기술은 놀라운 발전을 거듭하고 있다. 이러한 이유는 광섬유(optical fiber)가 일반 케이블에 비해서 탁월한 장점들이 있기 때문인데, 예를 들면 넓은 대역폭, 낮은 손실, 케이블간의 전자기적인 간섭(electromagnetic interference)에 자유로운 점, 그리고 특히 WDM(Wavelength Division Multiplexing)에 의한 네트워크 용량의 증가는 광섬유가 가지고 있는 가장 큰 매력일 것이다. (중략)

• Proceedings of the Optical Society of Korea Conference
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• 2002.11a
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• pp.286-287
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• 2002

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.2
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• pp.121-126
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• 2015

In general, the pearlescent pigment is a pigment which was used for optical characteristics like pearl, rainbow and metallic luster. Titanium dioxide coated mica plate developed by DuPont in 1965 is currently being used as a main part of pearlescent pigment for cosmetics. Although the smooth and clear surface substrate laminated with 2 ~ 3 ingredients is thicker than a previous monolayer coated substrate, it has been applied for cosmetics as the optical interference powder to realize stronger shine and brighter interference color than monolayer one. In this study, we developed a new optical interference powder with thinner and higher chroma than a current pearlescent pigment for the strong luster and bright interference color. It was prepared from the manufacturing process, in which the coated titanium dioxide precursor was changed and crystallized by coating and heat treatment process with a half of dividing the coated amount of titanium dioxide. We confirmed the dense coating of titanium dioxide grain with Scanning Electron Microscope and measured superior crystallization degree compared with a monolayer coated pearlescent pigment by X-ray Diffraction. It is concluded that our new pearlescent pigment had higher reflectivity of light and stronger interference color than previous products.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.7
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• pp.605-613
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• 2014

Scanning white-light interferometry is an important measurement option for many surfaces. However, serious profile measurement errors can be present when measuring free-form surfaces being highly curved or tilted. When the object surface slope is not zero, the object and reference rays are no longer common path and optical aberrations impact the measurement. Aberrations mainly occur at the beam splitter in the interference objective and from misalignment in the optical system. Both effects distort the white-light interference signal when the surface slope is not zero. In this paper, we describe a modified version of white-light interferometry for eliminating these measurement errors and improving the accuracy of white-light interferometry. Moreover, we report systematic errors that are caused by optical aberrations when the object is not flat, and compare our proposed method with the conventional processing algorithm using the random ball test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3435-3440
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• 2010

Unlike the electric method capable of checking only product defect, the real time optical metrology is suggested for measuring and visualizing vibration with respect to position of surface acoustic wave in RF device. The measuring limits and conditions for surface acoustic wave is given, and the interference and diffraction due to RF signal are analyzed by optical interpretation. A single mode laser and a 105MHz-center-frequency repeater filter were employed for experiments and theoretical analysis. In this paper, the optical metrology providing visual energy distribution and real time inspection for surface acoustic wave is proposed for development of high quality multi-service and multi-frequency RF module.

• Journal of the Optical Society of Korea
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• v.5 no.4
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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.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.1
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• pp.29-35
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• 2003

In this paper, we propose an improved image decryption system using a phase-encoded image and the principle of interference. An original image and a random image consist of only binary values. The phase-encoded original image is encrypted into a binary phase-only image by multiplying with a phase-encoded random key. Therefore the phase-encoded images have two phase values 0 or $\pi$. The proposed decryption technique is simply performed by interfering between a reference wave and a direct pixel-to-pixel mapping of the encrypted image with a decrypting key. Optical experiments confirmed that the proposed technique is a simple and robust architecture for optical encryption.